common/cli_hush.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  23  *        and many builtins derived from contributions by Erik Andersen
  24  *      miscellaneous bugfixes from Matt Kraai
  25  *
  26  * There are two big (and related) architecture differences between
  27  * this parser and the lash parser.  One is that this version is
  28  * actually designed from the ground up to understand nearly all
  29  * of the Bourne grammar.  The second, consequential change is that
  30  * the parser and input reader have been turned inside out.  Now,
  31  * the parser is in control, and asks for input as needed.  The old
  32  * way had the input reader in control, and it asked for parsing to
  33  * take place as needed.  The new way makes it much easier to properly
  34  * handle the recursion implicit in the various substitutions, especially
  35  * across continuation lines.
  36  *
  37  * Bash grammar not implemented: (how many of these were in original sh?)
  38  *      $@ (those sure look like weird quoting rules)
  39  *      $_
  40  *      ! negation operator for pipes
  41  *      &> and >& redirection of stdout+stderr
  42  *      Brace Expansion
  43  *      Tilde Expansion
  44  *      fancy forms of Parameter Expansion
  45  *      aliases
  46  *      Arithmetic Expansion
  47  *      <(list) and >(list) Process Substitution
  48  *      reserved words: case, esac, select, function
  49  *      Here Documents ( << word )
  50  *      Functions
  51  * Major bugs:
  52  *      job handling woefully incomplete and buggy
  53  *      reserved word execution woefully incomplete and buggy
  54  * to-do:
  55  *      port selected bugfixes from post-0.49 busybox lash - done?
  56  *      finish implementing reserved words: for, while, until, do, done
  57  *      change { and } from special chars to reserved words
  58  *      builtins: break, continue, eval, return, set, trap, ulimit
  59  *      test magic exec
  60  *      handle children going into background
  61  *      clean up recognition of null pipes
  62  *      check setting of global_argc and global_argv
  63  *      control-C handling, probably with longjmp
  64  *      follow IFS rules more precisely, including update semantics
  65  *      figure out what to do with backslash-newline
  66  *      explain why we use signal instead of sigaction
  67  *      propagate syntax errors, die on resource errors?
  68  *      continuation lines, both explicit and implicit - done?
  69  *      memory leak finding and plugging - done?
  70  *      more testing, especially quoting rules and redirection
  71  *      document how quoting rules not precisely followed for variable assignments
  72  *      maybe change map[] to use 2-bit entries
  73  *      (eventually) remove all the printf's
  74  */
  75
  76 #define __U_BOOT__
  77 #ifdef __U_BOOT__
  78 #include <malloc.h>         /* malloc, free, realloc*/
  79 #include <linux/ctype.h>    /* isalpha, isdigit */
  80 #include <common.h>        /* readline */
  81 #include <console.h>
  82 #include <bootretry.h>
  83 #include <cli.h>
  84 #include <cli_hush.h>
  85 #include <command.h>        /* find_cmd */
  86 #ifndef CONFIG_SYS_PROMPT_HUSH_PS2
  87 #define CONFIG_SYS_PROMPT_HUSH_PS2      "> "
  88 #endif
  89 #endif
  90 #ifndef __U_BOOT__
  91 #include <ctype.h>     /* isalpha, isdigit */
  92 #include <unistd.h>    /* getpid */
  93 #include <stdlib.h>    /* getenv, atoi */
  94 #include <string.h>    /* strchr */
  95 #include <stdio.h>     /* popen etc. */
  96 #include <glob.h>      /* glob, of course */
  97 #include <stdarg.h>    /* va_list */
  98 #include <errno.h>
  99 #include <fcntl.h>
 100 #include <getopt.h>    /* should be pretty obvious */
 101
 102 #include <sys/stat.h>  /* ulimit */
 103 #include <sys/types.h>
 104 #include <sys/wait.h>
 105 #include <signal.h>
 106
 107 /* #include <dmalloc.h> */
 108
 109 #if 1
 110 #include "busybox.h"
 111 #include "cmdedit.h"
 112 #else
 113 #define applet_name "hush"
 114 #include "standalone.h"
 115 #define hush_main main
 116 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 117 #define BB_BANNER
 118 #endif
 119 #endif
 120 #define SPECIAL_VAR_SYMBOL 03
 121 #define SUBSTED_VAR_SYMBOL 04
 122 #ifndef __U_BOOT__
 123 #define FLAG_EXIT_FROM_LOOP 1
 124 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 125 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 126
 127 #endif
 128
 129 #ifdef __U_BOOT__
 130 DECLARE_GLOBAL_DATA_PTR;
 131
 132 #define EXIT_SUCCESS 0
 133 #define EOF -1
 134 #define syntax() syntax_err()
 135 #define xstrdup strdup
 136 #define error_msg printf
 137 #else
 138 typedef enum {
 139         REDIRECT_INPUT     = 1,
 140         REDIRECT_OVERWRITE = 2,
 141         REDIRECT_APPEND    = 3,
 142         REDIRECT_HEREIS    = 4,
 143         REDIRECT_IO        = 5
 144 } redir_type;
 145
 146 /* The descrip member of this structure is only used to make debugging
 147  * output pretty */
 148 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 149         { 0,                         0, "()" },
 150         { O_RDONLY,                  0, "<"  },
 151         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 152         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 153         { O_RDONLY,                 -1, "<<" },
 154         { O_RDWR,                    1, "<>" }
 155 };
 156 #endif
 157
 158 typedef enum {
 159         PIPE_SEQ = 1,
 160         PIPE_AND = 2,
 161         PIPE_OR  = 3,
 162         PIPE_BG  = 4,
 163 } pipe_style;
 164
 165 /* might eventually control execution */
 166 typedef enum {
 167         RES_NONE  = 0,
 168         RES_IF    = 1,
 169         RES_THEN  = 2,
 170         RES_ELIF  = 3,
 171         RES_ELSE  = 4,
 172         RES_FI    = 5,
 173         RES_FOR   = 6,
 174         RES_WHILE = 7,
 175         RES_UNTIL = 8,
 176         RES_DO    = 9,
 177         RES_DONE  = 10,
 178         RES_XXXX  = 11,
 179         RES_IN    = 12,
 180         RES_SNTX  = 13
 181 } reserved_style;
 182 #define FLAG_END   (1<<RES_NONE)
 183 #define FLAG_IF    (1<<RES_IF)
 184 #define FLAG_THEN  (1<<RES_THEN)
 185 #define FLAG_ELIF  (1<<RES_ELIF)
 186 #define FLAG_ELSE  (1<<RES_ELSE)
 187 #define FLAG_FI    (1<<RES_FI)
 188 #define FLAG_FOR   (1<<RES_FOR)
 189 #define FLAG_WHILE (1<<RES_WHILE)
 190 #define FLAG_UNTIL (1<<RES_UNTIL)
 191 #define FLAG_DO    (1<<RES_DO)
 192 #define FLAG_DONE  (1<<RES_DONE)
 193 #define FLAG_IN    (1<<RES_IN)
 194 #define FLAG_START (1<<RES_XXXX)
 195
 196 /* This holds pointers to the various results of parsing */
 197 struct p_context {
 198         struct child_prog *child;
 199         struct pipe *list_head;
 200         struct pipe *pipe;
 201 #ifndef __U_BOOT__
 202         struct redir_struct *pending_redirect;
 203 #endif
 204         reserved_style w;
 205         int old_flag;                           /* for figuring out valid reserved words */
 206         struct p_context *stack;
 207         int type;                       /* define type of parser : ";$" common or special symbol */
 208         /* How about quoting status? */
 209 };
 210
 211 #ifndef __U_BOOT__
 212 struct redir_struct {
 213         redir_type type;                        /* type of redirection */
 214         int fd;                                         /* file descriptor being redirected */
 215         int dup;                                        /* -1, or file descriptor being duplicated */
 216         struct redir_struct *next;      /* pointer to the next redirect in the list */
 217         glob_t word;                            /* *word.gl_pathv is the filename */
 218 };
 219 #endif
 220
 221 struct child_prog {
 222 #ifndef __U_BOOT__
 223         pid_t pid;                                      /* 0 if exited */
 224 #endif
 225         char **argv;                            /* program name and arguments */
 226         /* was quoted when parsed; copy of struct o_string.nonnull field */
 227         int *argv_nonnull;
 228 #ifdef __U_BOOT__
 229         int    argc;                            /* number of program arguments */
 230 #endif
 231         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 232 #ifndef __U_BOOT__
 233         int subshell;                           /* flag, non-zero if group must be forked */
 234         struct redir_struct *redirects; /* I/O redirections */
 235         glob_t glob_result;                     /* result of parameter globbing */
 236         int is_stopped;                         /* is the program currently running? */
 237         struct pipe *family;            /* pointer back to the child's parent pipe */
 238 #endif
 239         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 240         int type;
 241 };
 242
 243 struct pipe {
 244 #ifndef __U_BOOT__
 245         int jobid;                                      /* job number */
 246 #endif
 247         int num_progs;                          /* total number of programs in job */
 248 #ifndef __U_BOOT__
 249         int running_progs;                      /* number of programs running */
 250         char *text;                                     /* name of job */
 251         char *cmdbuf;                           /* buffer various argv's point into */
 252         pid_t pgrp;                                     /* process group ID for the job */
 253 #endif
 254         struct child_prog *progs;       /* array of commands in pipe */
 255         struct pipe *next;                      /* to track background commands */
 256 #ifndef __U_BOOT__
 257         int stopped_progs;                      /* number of programs alive, but stopped */
 258         int job_context;                        /* bitmask defining current context */
 259 #endif
 260         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 261         reserved_style r_mode;          /* supports if, for, while, until */
 262 };
 263
 264 #ifndef __U_BOOT__
 265 struct close_me {
 266         int fd;
 267         struct close_me *next;
 268 };
 269 #endif
 270
 271 struct variables {
 272         char *name;
 273         char *value;
 274         int flg_export;
 275         int flg_read_only;
 276         struct variables *next;
 277 };
 278
 279 /* globals, connect us to the outside world
 280  * the first three support $?, $#, and $1 */
 281 #ifndef __U_BOOT__
 282 char **global_argv;
 283 unsigned int global_argc;
 284 #endif
 285 static unsigned int last_return_code;
 286 #ifndef __U_BOOT__
 287 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 288 #endif
 289
 290 /* "globals" within this file */
 291 static uchar *ifs;
 292 static char map[256];
 293 #ifndef __U_BOOT__
 294 static int fake_mode;
 295 static int interactive;
 296 static struct close_me *close_me_head;
 297 static const char *cwd;
 298 static struct pipe *job_list;
 299 static unsigned int last_bg_pid;
 300 static unsigned int last_jobid;
 301 static unsigned int shell_terminal;
 302 static char *PS1;
 303 static char *PS2;
 304 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 305 struct variables *top_vars = &shell_ver;
 306 #else
 307 static int flag_repeat = 0;
 308 static int do_repeat = 0;
 309 static struct variables *top_vars = NULL ;
 310 #endif /*__U_BOOT__ */
 311
 312 #define B_CHUNK (100)
 313 #define B_NOSPAC 1
 314
 315 typedef struct {
 316         char *data;
 317         int length;
 318         int maxlen;
 319         int quote;
 320         int nonnull;
 321 } o_string;
 322 #define NULL_O_STRING {NULL,0,0,0,0}
 323 /* used for initialization:
 324         o_string foo = NULL_O_STRING; */
 325
 326 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 327  * available?  Where is it documented? */
 328 struct in_str {
 329         const char *p;
 330 #ifndef __U_BOOT__
 331         char peek_buf[2];
 332 #endif
 333         int __promptme;
 334         int promptmode;
 335 #ifndef __U_BOOT__
 336         FILE *file;
 337 #endif
 338         int (*get) (struct in_str *);
 339         int (*peek) (struct in_str *);
 340 };
 341 #define b_getch(input) ((input)->get(input))
 342 #define b_peek(input) ((input)->peek(input))
 343
 344 #ifndef __U_BOOT__
 345 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 346
 347 struct built_in_command {
 348         char *cmd;                                      /* name */
 349         char *descr;                            /* description */
 350         int (*function) (struct child_prog *);  /* function ptr */
 351 };
 352 #endif
 353
 354 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 355 #if 0
 356 #define DEBUG_SHELL
 357 #endif
 358
 359 /* This should be in utility.c */
 360 #ifdef DEBUG_SHELL
 361 #ifndef __U_BOOT__
 362 static void debug_printf(const char *format, ...)
 363 {
 364         va_list args;
 365         va_start(args, format);
 366         vfprintf(stderr, format, args);
 367         va_end(args);
 368 }
 369 #else
 370 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 371 #endif
 372 #else
 373 static inline void debug_printf(const char *format, ...) { }
 374 #endif
 375 #define final_printf debug_printf
 376
 377 #ifdef __U_BOOT__
 378 static void syntax_err(void) {
 379          printf("syntax error\n");
 380 }
 381 #else
 382 static void __syntax(char *file, int line) {
 383         error_msg("syntax error %s:%d", file, line);
 384 }
 385 #define syntax() __syntax(__FILE__, __LINE__)
 386 #endif
 387
 388 #ifdef __U_BOOT__
 389 static void *xmalloc(size_t size);
 390 static void *xrealloc(void *ptr, size_t size);
 391 #else
 392 /* Index of subroutines: */
 393 /*   function prototypes for builtins */
 394 static int builtin_cd(struct child_prog *child);
 395 static int builtin_env(struct child_prog *child);
 396 static int builtin_eval(struct child_prog *child);
 397 static int builtin_exec(struct child_prog *child);
 398 static int builtin_exit(struct child_prog *child);
 399 static int builtin_export(struct child_prog *child);
 400 static int builtin_fg_bg(struct child_prog *child);
 401 static int builtin_help(struct child_prog *child);
 402 static int builtin_jobs(struct child_prog *child);
 403 static int builtin_pwd(struct child_prog *child);
 404 static int builtin_read(struct child_prog *child);
 405 static int builtin_set(struct child_prog *child);
 406 static int builtin_shift(struct child_prog *child);
 407 static int builtin_source(struct child_prog *child);
 408 static int builtin_umask(struct child_prog *child);
 409 static int builtin_unset(struct child_prog *child);
 410 static int builtin_not_written(struct child_prog *child);
 411 #endif
 412 /*   o_string manipulation: */
 413 static int b_check_space(o_string *o, int len);
 414 static int b_addchr(o_string *o, int ch);
 415 static void b_reset(o_string *o);
 416 static int b_addqchr(o_string *o, int ch, int quote);
 417 #ifndef __U_BOOT__
 418 static int b_adduint(o_string *o, unsigned int i);
 419 #endif
 420 /*  in_str manipulations: */
 421 static int static_get(struct in_str *i);
 422 static int static_peek(struct in_str *i);
 423 static int file_get(struct in_str *i);
 424 static int file_peek(struct in_str *i);
 425 #ifndef __U_BOOT__
 426 static void setup_file_in_str(struct in_str *i, FILE *f);
 427 #else
 428 static void setup_file_in_str(struct in_str *i);
 429 #endif
 430 static void setup_string_in_str(struct in_str *i, const char *s);
 431 #ifndef __U_BOOT__
 432 /*  close_me manipulations: */
 433 static void mark_open(int fd);
 434 static void mark_closed(int fd);
 435 static void close_all(void);
 436 #endif
 437 /*  "run" the final data structures: */
 438 static char *indenter(int i);
 439 static int free_pipe_list(struct pipe *head, int indent);
 440 static int free_pipe(struct pipe *pi, int indent);
 441 /*  really run the final data structures: */
 442 #ifndef __U_BOOT__
 443 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 444 #endif
 445 static int run_list_real(struct pipe *pi);
 446 #ifndef __U_BOOT__
 447 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 448 #endif
 449 static int run_pipe_real(struct pipe *pi);
 450 /*   extended glob support: */
 451 #ifndef __U_BOOT__
 452 static int globhack(const char *src, int flags, glob_t *pglob);
 453 static int glob_needed(const char *s);
 454 static int xglob(o_string *dest, int flags, glob_t *pglob);
 455 #endif
 456 /*   variable assignment: */
 457 static int is_assignment(const char *s);
 458 /*   data structure manipulation: */
 459 #ifndef __U_BOOT__
 460 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 461 #endif
 462 static void initialize_context(struct p_context *ctx);
 463 static int done_word(o_string *dest, struct p_context *ctx);
 464 static int done_command(struct p_context *ctx);
 465 static int done_pipe(struct p_context *ctx, pipe_style type);
 466 /*   primary string parsing: */
 467 #ifndef __U_BOOT__
 468 static int redirect_dup_num(struct in_str *input);
 469 static int redirect_opt_num(o_string *o);
 470 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 471 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 472 #endif
 473 static char *lookup_param(char *src);
 474 static char *make_string(char **inp, int *nonnull);
 475 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 476 #ifndef __U_BOOT__
 477 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 478 #endif
 479 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 480 /*   setup: */
 481 static int parse_stream_outer(struct in_str *inp, int flag);
 482 #ifndef __U_BOOT__
 483 static int parse_string_outer(const char *s, int flag);
 484 static int parse_file_outer(FILE *f);
 485 #endif
 486 #ifndef __U_BOOT__
 487 /*   job management: */
 488 static int checkjobs(struct pipe* fg_pipe);
 489 static void insert_bg_job(struct pipe *pi);
 490 static void remove_bg_job(struct pipe *pi);
 491 #endif
 492 /*     local variable support */
 493 static char **make_list_in(char **inp, char *name);
 494 static char *insert_var_value(char *inp);
 495 static char *insert_var_value_sub(char *inp, int tag_subst);
 496
 497 #ifndef __U_BOOT__
 498 /* Table of built-in functions.  They can be forked or not, depending on
 499  * context: within pipes, they fork.  As simple commands, they do not.
 500  * When used in non-forking context, they can change global variables
 501  * in the parent shell process.  If forked, of course they can not.
 502  * For example, 'unset foo | whatever' will parse and run, but foo will
 503  * still be set at the end. */
 504 static struct built_in_command bltins[] = {
 505         {"bg", "Resume a job in the background", builtin_fg_bg},
 506         {"break", "Exit for, while or until loop", builtin_not_written},
 507         {"cd", "Change working directory", builtin_cd},
 508         {"continue", "Continue for, while or until loop", builtin_not_written},
 509         {"env", "Print all environment variables", builtin_env},
 510         {"eval", "Construct and run shell command", builtin_eval},
 511         {"exec", "Exec command, replacing this shell with the exec'd process",
 512                 builtin_exec},
 513         {"exit", "Exit from shell()", builtin_exit},
 514         {"export", "Set environment variable", builtin_export},
 515         {"fg", "Bring job into the foreground", builtin_fg_bg},
 516         {"jobs", "Lists the active jobs", builtin_jobs},
 517         {"pwd", "Print current directory", builtin_pwd},
 518         {"read", "Input environment variable", builtin_read},
 519         {"return", "Return from a function", builtin_not_written},
 520         {"set", "Set/unset shell local variables", builtin_set},
 521         {"shift", "Shift positional parameters", builtin_shift},
 522         {"trap", "Trap signals", builtin_not_written},
 523         {"ulimit","Controls resource limits", builtin_not_written},
 524         {"umask","Sets file creation mask", builtin_umask},
 525         {"unset", "Unset environment variable", builtin_unset},
 526         {".", "Source-in and run commands in a file", builtin_source},
 527         {"help", "List shell built-in commands", builtin_help},
 528         {NULL, NULL, NULL}
 529 };
 530
 531 static const char *set_cwd(void)
 532 {
 533         if(cwd==unknown)
 534                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 535         cwd = xgetcwd((char *)cwd);
 536         if (!cwd)
 537                 cwd = unknown;
 538         return cwd;
 539 }
 540
 541 /* built-in 'eval' handler */
 542 static int builtin_eval(struct child_prog *child)
 543 {
 544         char *str = NULL;
 545         int rcode = EXIT_SUCCESS;
 546
 547         if (child->argv[1]) {
 548                 str = make_string(child->argv + 1);
 549                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 550                                         FLAG_PARSE_SEMICOLON);
 551                 free(str);
 552                 rcode = last_return_code;
 553         }
 554         return rcode;
 555 }
 556
 557 /* built-in 'cd <path>' handler */
 558 static int builtin_cd(struct child_prog *child)
 559 {
 560         char *newdir;
 561         if (child->argv[1] == NULL)
 562                 newdir = env_get("HOME");
 563         else
 564                 newdir = child->argv[1];
 565         if (chdir(newdir)) {
 566                 printf("cd: %s: %s\n", newdir, strerror(errno));
 567                 return EXIT_FAILURE;
 568         }
 569         set_cwd();
 570         return EXIT_SUCCESS;
 571 }
 572
 573 /* built-in 'env' handler */
 574 static int builtin_env(struct child_prog *dummy)
 575 {
 576         char **e = environ;
 577         if (e == NULL) return EXIT_FAILURE;
 578         for (; *e; e++) {
 579                 puts(*e);
 580         }
 581         return EXIT_SUCCESS;
 582 }
 583
 584 /* built-in 'exec' handler */
 585 static int builtin_exec(struct child_prog *child)
 586 {
 587         if (child->argv[1] == NULL)
 588                 return EXIT_SUCCESS;   /* Really? */
 589         child->argv++;
 590         pseudo_exec(child);
 591         /* never returns */
 592 }
 593
 594 /* built-in 'exit' handler */
 595 static int builtin_exit(struct child_prog *child)
 596 {
 597         if (child->argv[1] == NULL)
 598                 exit(last_return_code);
 599         exit (atoi(child->argv[1]));
 600 }
 601
 602 /* built-in 'export VAR=value' handler */
 603 static int builtin_export(struct child_prog *child)
 604 {
 605         int res = 0;
 606         char *name = child->argv[1];
 607
 608         if (name == NULL) {
 609                 return (builtin_env(child));
 610         }
 611
 612         name = strdup(name);
 613
 614         if(name) {
 615                 char *value = strchr(name, '=');
 616
 617                 if (!value) {
 618                         char *tmp;
 619                         /* They are exporting something without an =VALUE */
 620
 621                         value = get_local_var(name);
 622                         if (value) {
 623                                 size_t ln = strlen(name);
 624
 625                                 tmp = realloc(name, ln+strlen(value)+2);
 626                                 if(tmp==NULL)
 627                                         res = -1;
 628                                 else {
 629                                         sprintf(tmp+ln, "=%s", value);
 630                                         name = tmp;
 631                                 }
 632                         } else {
 633                                 /* bash does not return an error when trying to export
 634                                  * an undefined variable.  Do likewise. */
 635                                 res = 1;
 636                         }
 637                 }
 638         }
 639         if (res<0)
 640                 perror_msg("export");
 641         else if(res==0)
 642                 res = set_local_var(name, 1);
 643         else
 644                 res = 0;
 645         free(name);
 646         return res;
 647 }
 648
 649 /* built-in 'fg' and 'bg' handler */
 650 static int builtin_fg_bg(struct child_prog *child)
 651 {
 652         int i, jobnum;
 653         struct pipe *pi=NULL;
 654
 655         if (!interactive)
 656                 return EXIT_FAILURE;
 657         /* If they gave us no args, assume they want the last backgrounded task */
 658         if (!child->argv[1]) {
 659                 for (pi = job_list; pi; pi = pi->next) {
 660                         if (pi->jobid == last_jobid) {
 661                                 break;
 662                         }
 663                 }
 664                 if (!pi) {
 665                         error_msg("%s: no current job", child->argv[0]);
 666                         return EXIT_FAILURE;
 667                 }
 668         } else {
 669                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 670                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 671                         return EXIT_FAILURE;
 672                 }
 673                 for (pi = job_list; pi; pi = pi->next) {
 674                         if (pi->jobid == jobnum) {
 675                                 break;
 676                         }
 677                 }
 678                 if (!pi) {
 679                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 680                         return EXIT_FAILURE;
 681                 }
 682         }
 683
 684         if (*child->argv[0] == 'f') {
 685                 /* Put the job into the foreground.  */
 686                 tcsetpgrp(shell_terminal, pi->pgrp);
 687         }
 688
 689         /* Restart the processes in the job */
 690         for (i = 0; i < pi->num_progs; i++)
 691                 pi->progs[i].is_stopped = 0;
 692
 693         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 694                 if (i == ESRCH) {
 695                         remove_bg_job(pi);
 696                 } else {
 697                         perror_msg("kill (SIGCONT)");
 698                 }
 699         }
 700
 701         pi->stopped_progs = 0;
 702         return EXIT_SUCCESS;
 703 }
 704
 705 /* built-in 'help' handler */
 706 static int builtin_help(struct child_prog *dummy)
 707 {
 708         struct built_in_command *x;
 709
 710         printf("\nBuilt-in commands:\n");
 711         printf("-------------------\n");
 712         for (x = bltins; x->cmd; x++) {
 713                 if (x->descr==NULL)
 714                         continue;
 715                 printf("%s\t%s\n", x->cmd, x->descr);
 716         }
 717         printf("\n\n");
 718         return EXIT_SUCCESS;
 719 }
 720
 721 /* built-in 'jobs' handler */
 722 static int builtin_jobs(struct child_prog *child)
 723 {
 724         struct pipe *job;
 725         char *status_string;
 726
 727         for (job = job_list; job; job = job->next) {
 728                 if (job->running_progs == job->stopped_progs)
 729                         status_string = "Stopped";
 730                 else
 731                         status_string = "Running";
 732
 733                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 734         }
 735         return EXIT_SUCCESS;
 736 }
 737
 738
 739 /* built-in 'pwd' handler */
 740 static int builtin_pwd(struct child_prog *dummy)
 741 {
 742         puts(set_cwd());
 743         return EXIT_SUCCESS;
 744 }
 745
 746 /* built-in 'read VAR' handler */
 747 static int builtin_read(struct child_prog *child)
 748 {
 749         int res;
 750
 751         if (child->argv[1]) {
 752                 char string[BUFSIZ];
 753                 char *var = 0;
 754
 755                 string[0] = 0;  /* In case stdin has only EOF */
 756                 /* read string */
 757                 fgets(string, sizeof(string), stdin);
 758                 chomp(string);
 759                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 760                 if(var) {
 761                         sprintf(var, "%s=%s", child->argv[1], string);
 762                         res = set_local_var(var, 0);
 763                 } else
 764                         res = -1;
 765                 if (res)
 766                         fprintf(stderr, "read: %m\n");
 767                 free(var);      /* So not move up to avoid breaking errno */
 768                 return res;
 769         } else {
 770                 do res=getchar(); while(res!='\n' && res!=EOF);
 771                 return 0;
 772         }
 773 }
 774
 775 /* built-in 'set VAR=value' handler */
 776 static int builtin_set(struct child_prog *child)
 777 {
 778         char *temp = child->argv[1];
 779         struct variables *e;
 780
 781         if (temp == NULL)
 782                 for(e = top_vars; e; e=e->next)
 783                         printf("%s=%s\n", e->name, e->value);
 784         else
 785                 set_local_var(temp, 0);
 786
 787                 return EXIT_SUCCESS;
 788 }
 789
 790
 791 /* Built-in 'shift' handler */
 792 static int builtin_shift(struct child_prog *child)
 793 {
 794         int n=1;
 795         if (child->argv[1]) {
 796                 n=atoi(child->argv[1]);
 797         }
 798         if (n>=0 && n<global_argc) {
 799                 /* XXX This probably breaks $0 */
 800                 global_argc -= n;
 801                 global_argv += n;
 802                 return EXIT_SUCCESS;
 803         } else {
 804                 return EXIT_FAILURE;
 805         }
 806 }
 807
 808 /* Built-in '.' handler (read-in and execute commands from file) */
 809 static int builtin_source(struct child_prog *child)
 810 {
 811         FILE *input;
 812         int status;
 813
 814         if (child->argv[1] == NULL)
 815                 return EXIT_FAILURE;
 816
 817         /* XXX search through $PATH is missing */
 818         input = fopen(child->argv[1], "r");
 819         if (!input) {
 820                 error_msg("Couldn't open file '%s'", child->argv[1]);
 821                 return EXIT_FAILURE;
 822         }
 823
 824         /* Now run the file */
 825         /* XXX argv and argc are broken; need to save old global_argv
 826          * (pointer only is OK!) on this stack frame,
 827          * set global_argv=child->argv+1, recurse, and restore. */
 828         mark_open(fileno(input));
 829         status = parse_file_outer(input);
 830         mark_closed(fileno(input));
 831         fclose(input);
 832         return (status);
 833 }
 834
 835 static int builtin_umask(struct child_prog *child)
 836 {
 837         mode_t new_umask;
 838         const char *arg = child->argv[1];
 839         char *end;
 840         if (arg) {
 841                 new_umask=strtoul(arg, &end, 8);
 842                 if (*end!='\0' || end == arg) {
 843                         return EXIT_FAILURE;
 844                 }
 845         } else {
 846                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 847         }
 848         umask(new_umask);
 849         return EXIT_SUCCESS;
 850 }
 851
 852 /* built-in 'unset VAR' handler */
 853 static int builtin_unset(struct child_prog *child)
 854 {
 855         /* bash returned already true */
 856         unset_local_var(child->argv[1]);
 857         return EXIT_SUCCESS;
 858 }
 859
 860 static int builtin_not_written(struct child_prog *child)
 861 {
 862         printf("builtin_%s not written\n",child->argv[0]);
 863         return EXIT_FAILURE;
 864 }
 865 #endif
 866
 867 static int b_check_space(o_string *o, int len)
 868 {
 869         /* It would be easy to drop a more restrictive policy
 870          * in here, such as setting a maximum string length */
 871         if (o->length + len > o->maxlen) {
 872                 char *old_data = o->data;
 873                 /* assert (data == NULL || o->maxlen != 0); */
 874                 o->maxlen += max(2*len, B_CHUNK);
 875                 o->data = realloc(o->data, 1 + o->maxlen);
 876                 if (o->data == NULL) {
 877                         free(old_data);
 878                 }
 879         }
 880         return o->data == NULL;
 881 }
 882
 883 static int b_addchr(o_string *o, int ch)
 884 {
 885         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 886         if (b_check_space(o, 1)) return B_NOSPAC;
 887         o->data[o->length] = ch;
 888         o->length++;
 889         o->data[o->length] = '\0';
 890         return 0;
 891 }
 892
 893 static void b_reset(o_string *o)
 894 {
 895         o->length = 0;
 896         o->nonnull = 0;
 897         if (o->data != NULL) *o->data = '\0';
 898 }
 899
 900 static void b_free(o_string *o)
 901 {
 902         b_reset(o);
 903         free(o->data);
 904         o->data = NULL;
 905         o->maxlen = 0;
 906 }
 907
 908 /* My analysis of quoting semantics tells me that state information
 909  * is associated with a destination, not a source.
 910  */
 911 static int b_addqchr(o_string *o, int ch, int quote)
 912 {
 913         if (quote && strchr("*?[\\",ch)) {
 914                 int rc;
 915                 rc = b_addchr(o, '\\');
 916                 if (rc) return rc;
 917         }
 918         return b_addchr(o, ch);
 919 }
 920
 921 #ifndef __U_BOOT__
 922 static int b_adduint(o_string *o, unsigned int i)
 923 {
 924         int r;
 925         char *p = simple_itoa(i);
 926         /* no escape checking necessary */
 927         do r=b_addchr(o, *p++); while (r==0 && *p);
 928         return r;
 929 }
 930 #endif
 931
 932 static int static_get(struct in_str *i)
 933 {
 934         int ch = *i->p++;
 935         if (ch=='\0') return EOF;
 936         return ch;
 937 }
 938
 939 static int static_peek(struct in_str *i)
 940 {
 941         return *i->p;
 942 }
 943
 944 #ifndef __U_BOOT__
 945 static inline void cmdedit_set_initial_prompt(void)
 946 {
 947 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 948         PS1 = NULL;
 949 #else
 950         PS1 = env_get("PS1");
 951         if(PS1==0)
 952                 PS1 = "\\w \\$ ";
 953 #endif
 954 }
 955
 956 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 957 {
 958         debug_printf("setup_prompt_string %d ",promptmode);
 959 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 960         /* Set up the prompt */
 961         if (promptmode == 1) {
 962                 free(PS1);
 963                 PS1=xmalloc(strlen(cwd)+4);
 964                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 965                 *prompt_str = PS1;
 966         } else {
 967                 *prompt_str = PS2;
 968         }
 969 #else
 970         *prompt_str = (promptmode==1)? PS1 : PS2;
 971 #endif
 972         debug_printf("result %s\n",*prompt_str);
 973 }
 974 #endif
 975
 976 #ifdef __U_BOOT__
 977 static int uboot_cli_readline(struct in_str *i)
 978 {
 979         char *prompt;
 980         char __maybe_unused *ps_prompt = NULL;
 981
 982         if (i->promptmode == 1)
 983                 prompt = CONFIG_SYS_PROMPT;
 984         else
 985                 prompt = CONFIG_SYS_PROMPT_HUSH_PS2;
 986
 987 #ifdef CONFIG_CMDLINE_PS_SUPPORT
 988         if (i->promptmode == 1)
 989                 ps_prompt = env_get("PS1");
 990         else
 991                 ps_prompt = env_get("PS2");
 992         if (ps_prompt)
 993                 prompt = ps_prompt;
 994 #endif
 995
 996         return cli_readline(prompt);
 997 }
 998 #endif
 999
1000 static void get_user_input(struct in_str *i)
1001 {
1002 #ifndef __U_BOOT__
1003         char *prompt_str;
1004         static char the_command[BUFSIZ];
1005
1006         setup_prompt_string(i->promptmode, &prompt_str);
1007 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1008         /*
1009          ** enable command line editing only while a command line
1010          ** is actually being read; otherwise, we'll end up bequeathing
1011          ** atexit() handlers and other unwanted stuff to our
1012          ** child processes (rob@sysgo.de)
1013          */
1014         cmdedit_read_input(prompt_str, the_command);
1015 #else
1016         fputs(prompt_str, stdout);
1017         fflush(stdout);
1018         the_command[0]=fgetc(i->file);
1019         the_command[1]='\0';
1020 #endif
1021         fflush(stdout);
1022         i->p = the_command;
1023 #else
1024         int n;
1025         static char the_command[CONFIG_SYS_CBSIZE + 1];
1026
1027         bootretry_reset_cmd_timeout();
1028         i->__promptme = 1;
1029         n = uboot_cli_readline(i);
1030
1031 #ifdef CONFIG_BOOT_RETRY_TIME
1032         if (n == -2) {
1033           puts("\nTimeout waiting for command\n");
1034 #  ifdef CONFIG_RESET_TO_RETRY
1035           do_reset(NULL, 0, 0, NULL);
1036 #  else
1037 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1038 #  endif
1039         }
1040 #endif
1041         if (n == -1 ) {
1042                 flag_repeat = 0;
1043                 i->__promptme = 0;
1044         }
1045         n = strlen(console_buffer);
1046         console_buffer[n] = '\n';
1047         console_buffer[n+1]= '\0';
1048         if (had_ctrlc()) flag_repeat = 0;
1049         clear_ctrlc();
1050         do_repeat = 0;
1051         if (i->promptmode == 1) {
1052                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1053                         strcpy(the_command,console_buffer);
1054                 }
1055                 else {
1056                         if (console_buffer[0] != '\n') {
1057                                 strcpy(the_command,console_buffer);
1058                                 flag_repeat = 1;
1059                         }
1060                         else {
1061                                 do_repeat = 1;
1062                         }
1063                 }
1064                 i->p = the_command;
1065         }
1066         else {
1067                 if (console_buffer[0] != '\n') {
1068                         if (strlen(the_command) + strlen(console_buffer)
1069                             < CONFIG_SYS_CBSIZE) {
1070                                 n = strlen(the_command);
1071                                 the_command[n-1] = ' ';
1072                                 strcpy(&the_command[n],console_buffer);
1073                         }
1074                         else {
1075                                 the_command[0] = '\n';
1076                                 the_command[1] = '\0';
1077                                 flag_repeat = 0;
1078                         }
1079                 }
1080                 if (i->__promptme == 0) {
1081                         the_command[0] = '\n';
1082                         the_command[1] = '\0';
1083                 }
1084                 i->p = console_buffer;
1085         }
1086 #endif
1087 }
1088
1089 /* This is the magic location that prints prompts
1090  * and gets data back from the user */
1091 static int file_get(struct in_str *i)
1092 {
1093         int ch;
1094
1095         ch = 0;
1096         /* If there is data waiting, eat it up */
1097         if (i->p && *i->p) {
1098                 ch = *i->p++;
1099         } else {
1100                 /* need to double check i->file because we might be doing something
1101                  * more complicated by now, like sourcing or substituting. */
1102 #ifndef __U_BOOT__
1103                 if (i->__promptme && interactive && i->file == stdin) {
1104                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1105 #else
1106                         while(! i->p  || strlen(i->p)==0 ) {
1107 #endif
1108                                 get_user_input(i);
1109                         }
1110                         i->promptmode=2;
1111 #ifndef __U_BOOT__
1112                         i->__promptme = 0;
1113 #endif
1114                         if (i->p && *i->p) {
1115                                 ch = *i->p++;
1116                         }
1117 #ifndef __U_BOOT__
1118                 } else {
1119                         ch = fgetc(i->file);
1120                 }
1121
1122 #endif
1123                 debug_printf("b_getch: got a %d\n", ch);
1124         }
1125 #ifndef __U_BOOT__
1126         if (ch == '\n') i->__promptme=1;
1127 #endif
1128         return ch;
1129 }
1130
1131 /* All the callers guarantee this routine will never be
1132  * used right after a newline, so prompting is not needed.
1133  */
1134 static int file_peek(struct in_str *i)
1135 {
1136 #ifndef __U_BOOT__
1137         if (i->p && *i->p) {
1138 #endif
1139                 return *i->p;
1140 #ifndef __U_BOOT__
1141         } else {
1142                 i->peek_buf[0] = fgetc(i->file);
1143                 i->peek_buf[1] = '\0';
1144                 i->p = i->peek_buf;
1145                 debug_printf("b_peek: got a %d\n", *i->p);
1146                 return *i->p;
1147         }
1148 #endif
1149 }
1150
1151 #ifndef __U_BOOT__
1152 static void setup_file_in_str(struct in_str *i, FILE *f)
1153 #else
1154 static void setup_file_in_str(struct in_str *i)
1155 #endif
1156 {
1157         i->peek = file_peek;
1158         i->get = file_get;
1159         i->__promptme=1;
1160         i->promptmode=1;
1161 #ifndef __U_BOOT__
1162         i->file = f;
1163 #endif
1164         i->p = NULL;
1165 }
1166
1167 static void setup_string_in_str(struct in_str *i, const char *s)
1168 {
1169         i->peek = static_peek;
1170         i->get = static_get;
1171         i->__promptme=1;
1172         i->promptmode=1;
1173         i->p = s;
1174 }
1175
1176 #ifndef __U_BOOT__
1177 static void mark_open(int fd)
1178 {
1179         struct close_me *new = xmalloc(sizeof(struct close_me));
1180         new->fd = fd;
1181         new->next = close_me_head;
1182         close_me_head = new;
1183 }
1184
1185 static void mark_closed(int fd)
1186 {
1187         struct close_me *tmp;
1188         if (close_me_head == NULL || close_me_head->fd != fd)
1189                 error_msg_and_die("corrupt close_me");
1190         tmp = close_me_head;
1191         close_me_head = close_me_head->next;
1192         free(tmp);
1193 }
1194
1195 static void close_all(void)
1196 {
1197         struct close_me *c;
1198         for (c=close_me_head; c; c=c->next) {
1199                 close(c->fd);
1200         }
1201         close_me_head = NULL;
1202 }
1203
1204 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1205  * and stderr if they are redirected. */
1206 static int setup_redirects(struct child_prog *prog, int squirrel[])
1207 {
1208         int openfd, mode;
1209         struct redir_struct *redir;
1210
1211         for (redir=prog->redirects; redir; redir=redir->next) {
1212                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1213                         /* something went wrong in the parse.  Pretend it didn't happen */
1214                         continue;
1215                 }
1216                 if (redir->dup == -1) {
1217                         mode=redir_table[redir->type].mode;
1218                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1219                         if (openfd < 0) {
1220                         /* this could get lost if stderr has been redirected, but
1221                            bash and ash both lose it as well (though zsh doesn't!) */
1222                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1223                                 return 1;
1224                         }
1225                 } else {
1226                         openfd = redir->dup;
1227                 }
1228
1229                 if (openfd != redir->fd) {
1230                         if (squirrel && redir->fd < 3) {
1231                                 squirrel[redir->fd] = dup(redir->fd);
1232                         }
1233                         if (openfd == -3) {
1234                                 close(openfd);
1235                         } else {
1236                                 dup2(openfd, redir->fd);
1237                                 if (redir->dup == -1)
1238                                         close (openfd);
1239                         }
1240                 }
1241         }
1242         return 0;
1243 }
1244
1245 static void restore_redirects(int squirrel[])
1246 {
1247         int i, fd;
1248         for (i=0; i<3; i++) {
1249                 fd = squirrel[i];
1250                 if (fd != -1) {
1251                         /* No error checking.  I sure wouldn't know what
1252                          * to do with an error if I found one! */
1253                         dup2(fd, i);
1254                         close(fd);
1255                 }
1256         }
1257 }
1258
1259 /* never returns */
1260 /* XXX no exit() here.  If you don't exec, use _exit instead.
1261  * The at_exit handlers apparently confuse the calling process,
1262  * in particular stdin handling.  Not sure why? */
1263 static void pseudo_exec(struct child_prog *child)
1264 {
1265         int i, rcode;
1266         char *p;
1267         struct built_in_command *x;
1268         if (child->argv) {
1269                 for (i=0; is_assignment(child->argv[i]); i++) {
1270                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1271                         p = insert_var_value(child->argv[i]);
1272                         putenv(strdup(p));
1273                         if (p != child->argv[i]) free(p);
1274                 }
1275                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1276                                         to exit, and therefore don't need to keep data
1277                                         structures consistent for free() use. */
1278                 /* If a variable is assigned in a forest, and nobody listens,
1279                  * was it ever really set?
1280                  */
1281                 if (child->argv[0] == NULL) {
1282                         _exit(EXIT_SUCCESS);
1283                 }
1284
1285                 /*
1286                  * Check if the command matches any of the builtins.
1287                  * Depending on context, this might be redundant.  But it's
1288                  * easier to waste a few CPU cycles than it is to figure out
1289                  * if this is one of those cases.
1290                  */
1291                 for (x = bltins; x->cmd; x++) {
1292                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1293                                 debug_printf("builtin exec %s\n", child->argv[0]);
1294                                 rcode = x->function(child);
1295                                 fflush(stdout);
1296                                 _exit(rcode);
1297                         }
1298                 }
1299
1300                 /* Check if the command matches any busybox internal commands
1301                  * ("applets") here.
1302                  * FIXME: This feature is not 100% safe, since
1303                  * BusyBox is not fully reentrant, so we have no guarantee the things
1304                  * from the .bss are still zeroed, or that things from .data are still
1305                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1306                  * really dislike relying on /proc for things.  We could exec ourself
1307                  * from global_argv[0], but if we are in a chroot, we may not be able
1308                  * to find ourself... */
1309 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1310                 {
1311                         int argc_l;
1312                         char** argv_l=child->argv;
1313                         char *name = child->argv[0];
1314
1315 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1316                         /* Following discussions from November 2000 on the busybox mailing
1317                          * list, the default configuration, (without
1318                          * get_last_path_component()) lets the user force use of an
1319                          * external command by specifying the full (with slashes) filename.
1320                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1321                          * _aways_ override external commands, so if you want to run
1322                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1323                          * filesystem and is _not_ busybox.  Some systems may want this,
1324                          * most do not.  */
1325                         name = get_last_path_component(name);
1326 #endif
1327                         /* Count argc for use in a second... */
1328                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1329                         optind = 1;
1330                         debug_printf("running applet %s\n", name);
1331                         run_applet_by_name(name, argc_l, child->argv);
1332                 }
1333 #endif
1334                 debug_printf("exec of %s\n",child->argv[0]);
1335                 execvp(child->argv[0],child->argv);
1336                 perror_msg("couldn't exec: %s",child->argv[0]);
1337                 _exit(1);
1338         } else if (child->group) {
1339                 debug_printf("runtime nesting to group\n");
1340                 interactive=0;    /* crucial!!!! */
1341                 rcode = run_list_real(child->group);
1342                 /* OK to leak memory by not calling free_pipe_list,
1343                  * since this process is about to exit */
1344                 _exit(rcode);
1345         } else {
1346                 /* Can happen.  See what bash does with ">foo" by itself. */
1347                 debug_printf("trying to pseudo_exec null command\n");
1348                 _exit(EXIT_SUCCESS);
1349         }
1350 }
1351
1352 static void insert_bg_job(struct pipe *pi)
1353 {
1354         struct pipe *thejob;
1355
1356         /* Linear search for the ID of the job to use */
1357         pi->jobid = 1;
1358         for (thejob = job_list; thejob; thejob = thejob->next)
1359                 if (thejob->jobid >= pi->jobid)
1360                         pi->jobid = thejob->jobid + 1;
1361
1362         /* add thejob to the list of running jobs */
1363         if (!job_list) {
1364                 thejob = job_list = xmalloc(sizeof(*thejob));
1365         } else {
1366                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1367                 thejob->next = xmalloc(sizeof(*thejob));
1368                 thejob = thejob->next;
1369         }
1370
1371         /* physically copy the struct job */
1372         memcpy(thejob, pi, sizeof(struct pipe));
1373         thejob->next = NULL;
1374         thejob->running_progs = thejob->num_progs;
1375         thejob->stopped_progs = 0;
1376         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1377
1378         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1379         {
1380                 char *bar=thejob->text;
1381                 char **foo=pi->progs[0].argv;
1382                 while(foo && *foo) {
1383                         bar += sprintf(bar, "%s ", *foo++);
1384                 }
1385         }
1386
1387         /* we don't wait for background thejobs to return -- append it
1388            to the list of backgrounded thejobs and leave it alone */
1389         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1390         last_bg_pid = thejob->progs[0].pid;
1391         last_jobid = thejob->jobid;
1392 }
1393
1394 /* remove a backgrounded job */
1395 static void remove_bg_job(struct pipe *pi)
1396 {
1397         struct pipe *prev_pipe;
1398
1399         if (pi == job_list) {
1400                 job_list = pi->next;
1401         } else {
1402                 prev_pipe = job_list;
1403                 while (prev_pipe->next != pi)
1404                         prev_pipe = prev_pipe->next;
1405                 prev_pipe->next = pi->next;
1406         }
1407         if (job_list)
1408                 last_jobid = job_list->jobid;
1409         else
1410                 last_jobid = 0;
1411
1412         pi->stopped_progs = 0;
1413         free_pipe(pi, 0);
1414         free(pi);
1415 }
1416
1417 /* Checks to see if any processes have exited -- if they
1418    have, figure out why and see if a job has completed */
1419 static int checkjobs(struct pipe* fg_pipe)
1420 {
1421         int attributes;
1422         int status;
1423         int prognum = 0;
1424         struct pipe *pi;
1425         pid_t childpid;
1426
1427         attributes = WUNTRACED;
1428         if (fg_pipe==NULL) {
1429                 attributes |= WNOHANG;
1430         }
1431
1432         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1433                 if (fg_pipe) {
1434                         int i, rcode = 0;
1435                         for (i=0; i < fg_pipe->num_progs; i++) {
1436                                 if (fg_pipe->progs[i].pid == childpid) {
1437                                         if (i==fg_pipe->num_progs-1)
1438                                                 rcode=WEXITSTATUS(status);
1439                                         (fg_pipe->num_progs)--;
1440                                         return(rcode);
1441                                 }
1442                         }
1443                 }
1444
1445                 for (pi = job_list; pi; pi = pi->next) {
1446                         prognum = 0;
1447                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1448                                 prognum++;
1449                         }
1450                         if (prognum < pi->num_progs)
1451                                 break;
1452                 }
1453
1454                 if(pi==NULL) {
1455                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1456                         continue;
1457                 }
1458
1459                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1460                         /* child exited */
1461                         pi->running_progs--;
1462                         pi->progs[prognum].pid = 0;
1463
1464                         if (!pi->running_progs) {
1465                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1466                                 remove_bg_job(pi);
1467                         }
1468                 } else {
1469                         /* child stopped */
1470                         pi->stopped_progs++;
1471                         pi->progs[prognum].is_stopped = 1;
1472
1473 #if 0
1474                         /* Printing this stuff is a pain, since it tends to
1475                          * overwrite the prompt an inconveinient moments.  So
1476                          * don't do that.  */
1477                         if (pi->stopped_progs == pi->num_progs) {
1478                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1479                         }
1480 #endif
1481                 }
1482         }
1483
1484         if (childpid == -1 && errno != ECHILD)
1485                 perror_msg("waitpid");
1486
1487         /* move the shell to the foreground */
1488         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1489         /*      perror_msg("tcsetpgrp-2"); */
1490         return -1;
1491 }
1492
1493 /* Figure out our controlling tty, checking in order stderr,
1494  * stdin, and stdout.  If check_pgrp is set, also check that
1495  * we belong to the foreground process group associated with
1496  * that tty.  The value of shell_terminal is needed in order to call
1497  * tcsetpgrp(shell_terminal, ...); */
1498 void controlling_tty(int check_pgrp)
1499 {
1500         pid_t curpgrp;
1501
1502         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1503                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1504                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1505                 goto shell_terminal_error;
1506
1507         if (check_pgrp && curpgrp != getpgid(0))
1508                 goto shell_terminal_error;
1509
1510         return;
1511
1512 shell_terminal_error:
1513                 shell_terminal = -1;
1514                 return;
1515 }
1516 #endif
1517
1518 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1519  * to finish.  See checkjobs().
1520  *
1521  * return code is normally -1, when the caller has to wait for children
1522  * to finish to determine the exit status of the pipe.  If the pipe
1523  * is a simple builtin command, however, the action is done by the
1524  * time run_pipe_real returns, and the exit code is provided as the
1525  * return value.
1526  *
1527  * The input of the pipe is always stdin, the output is always
1528  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1529  * because it tries to avoid running the command substitution in
1530  * subshell, when that is in fact necessary.  The subshell process
1531  * now has its stdout directed to the input of the appropriate pipe,
1532  * so this routine is noticeably simpler.
1533  */
1534 static int run_pipe_real(struct pipe *pi)
1535 {
1536         int i;
1537 #ifndef __U_BOOT__
1538         int nextin, nextout;
1539         int pipefds[2];                         /* pipefds[0] is for reading */
1540         struct child_prog *child;
1541         struct built_in_command *x;
1542         char *p;
1543 # if __GNUC__
1544         /* Avoid longjmp clobbering */
1545         (void) &i;
1546         (void) &nextin;
1547         (void) &nextout;
1548         (void) &child;
1549 # endif
1550 #else
1551         int nextin;
1552         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1553         struct child_prog *child;
1554         char *p;
1555 # if __GNUC__
1556         /* Avoid longjmp clobbering */
1557         (void) &i;
1558         (void) &nextin;
1559         (void) &child;
1560 # endif
1561 #endif  /* __U_BOOT__ */
1562
1563         nextin = 0;
1564 #ifndef __U_BOOT__
1565         pi->pgrp = -1;
1566 #endif
1567
1568         /* Check if this is a simple builtin (not part of a pipe).
1569          * Builtins within pipes have to fork anyway, and are handled in
1570          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1571          */
1572         if (pi->num_progs == 1) child = & (pi->progs[0]);
1573 #ifndef __U_BOOT__
1574         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1575                 int squirrel[] = {-1, -1, -1};
1576                 int rcode;
1577                 debug_printf("non-subshell grouping\n");
1578                 setup_redirects(child, squirrel);
1579                 /* XXX could we merge code with following builtin case,
1580                  * by creating a pseudo builtin that calls run_list_real? */
1581                 rcode = run_list_real(child->group);
1582                 restore_redirects(squirrel);
1583 #else
1584                 if (pi->num_progs == 1 && child->group) {
1585                 int rcode;
1586                 debug_printf("non-subshell grouping\n");
1587                 rcode = run_list_real(child->group);
1588 #endif
1589                 return rcode;
1590         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1591                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1592                 if (i!=0 && child->argv[i]==NULL) {
1593                         /* assignments, but no command: set the local environment */
1594                         for (i=0; child->argv[i]!=NULL; i++) {
1595
1596                                 /* Ok, this case is tricky.  We have to decide if this is a
1597                                  * local variable, or an already exported variable.  If it is
1598                                  * already exported, we have to export the new value.  If it is
1599                                  * not exported, we need only set this as a local variable.
1600                                  * This junk is all to decide whether or not to export this
1601                                  * variable. */
1602                                 int export_me=0;
1603                                 char *name, *value;
1604                                 name = xstrdup(child->argv[i]);
1605                                 debug_printf("Local environment set: %s\n", name);
1606                                 value = strchr(name, '=');
1607                                 if (value)
1608                                         *value=0;
1609 #ifndef __U_BOOT__
1610                                 if ( get_local_var(name)) {
1611                                         export_me=1;
1612                                 }
1613 #endif
1614                                 free(name);
1615                                 p = insert_var_value(child->argv[i]);
1616                                 set_local_var(p, export_me);
1617                                 if (p != child->argv[i]) free(p);
1618                         }
1619                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1620                 }
1621                 for (i = 0; is_assignment(child->argv[i]); i++) {
1622                         p = insert_var_value(child->argv[i]);
1623 #ifndef __U_BOOT__
1624                         putenv(strdup(p));
1625 #else
1626                         set_local_var(p, 0);
1627 #endif
1628                         if (p != child->argv[i]) {
1629                                 child->sp--;
1630                                 free(p);
1631                         }
1632                 }
1633                 if (child->sp) {
1634                         char * str = NULL;
1635
1636                         str = make_string(child->argv + i,
1637                                           child->argv_nonnull + i);
1638                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1639                         free(str);
1640                         return last_return_code;
1641                 }
1642 #ifndef __U_BOOT__
1643                 for (x = bltins; x->cmd; x++) {
1644                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1645                                 int squirrel[] = {-1, -1, -1};
1646                                 int rcode;
1647                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1648                                         debug_printf("magic exec\n");
1649                                         setup_redirects(child,NULL);
1650                                         return EXIT_SUCCESS;
1651                                 }
1652                                 debug_printf("builtin inline %s\n", child->argv[0]);
1653                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1654                                  * This is perfect for work that comes after exec().
1655                                  * Is it really safe for inline use?  Experimentally,
1656                                  * things seem to work with glibc. */
1657                                 setup_redirects(child, squirrel);
1658
1659                                 child->argv += i;  /* XXX horrible hack */
1660                                 rcode = x->function(child);
1661                                 /* XXX restore hack so free() can work right */
1662                                 child->argv -= i;
1663                                 restore_redirects(squirrel);
1664                         }
1665                         return rcode;
1666                 }
1667 #else
1668                 /* check ";", because ,example , argv consist from
1669                  * "help;flinfo" must not execute
1670                  */
1671                 if (strchr(child->argv[i], ';')) {
1672                         printf("Unknown command '%s' - try 'help' or use "
1673                                         "'run' command\n", child->argv[i]);
1674                         return -1;
1675                 }
1676                 /* Process the command */
1677                 return cmd_process(flag, child->argc, child->argv,
1678                                    &flag_repeat, NULL);
1679 #endif
1680         }
1681 #ifndef __U_BOOT__
1682
1683         for (i = 0; i < pi->num_progs; i++) {
1684                 child = & (pi->progs[i]);
1685
1686                 /* pipes are inserted between pairs of commands */
1687                 if ((i + 1) < pi->num_progs) {
1688                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1689                         nextout = pipefds[1];
1690                 } else {
1691                         nextout=1;
1692                         pipefds[0] = -1;
1693                 }
1694
1695                 /* XXX test for failed fork()? */
1696                 if (!(child->pid = fork())) {
1697                         /* Set the handling for job control signals back to the default.  */
1698                         signal(SIGINT, SIG_DFL);
1699                         signal(SIGQUIT, SIG_DFL);
1700                         signal(SIGTERM, SIG_DFL);
1701                         signal(SIGTSTP, SIG_DFL);
1702                         signal(SIGTTIN, SIG_DFL);
1703                         signal(SIGTTOU, SIG_DFL);
1704                         signal(SIGCHLD, SIG_DFL);
1705
1706                         close_all();
1707
1708                         if (nextin != 0) {
1709                                 dup2(nextin, 0);
1710                                 close(nextin);
1711                         }
1712                         if (nextout != 1) {
1713                                 dup2(nextout, 1);
1714                                 close(nextout);
1715                         }
1716                         if (pipefds[0]!=-1) {
1717                                 close(pipefds[0]);  /* opposite end of our output pipe */
1718                         }
1719
1720                         /* Like bash, explicit redirects override pipes,
1721                          * and the pipe fd is available for dup'ing. */
1722                         setup_redirects(child,NULL);
1723
1724                         if (interactive && pi->followup!=PIPE_BG) {
1725                                 /* If we (the child) win the race, put ourselves in the process
1726                                  * group whose leader is the first process in this pipe. */
1727                                 if (pi->pgrp < 0) {
1728                                         pi->pgrp = getpid();
1729                                 }
1730                                 if (setpgid(0, pi->pgrp) == 0) {
1731                                         tcsetpgrp(2, pi->pgrp);
1732                                 }
1733                         }
1734
1735                         pseudo_exec(child);
1736                 }
1737
1738
1739                 /* put our child in the process group whose leader is the
1740                    first process in this pipe */
1741                 if (pi->pgrp < 0) {
1742                         pi->pgrp = child->pid;
1743                 }
1744                 /* Don't check for errors.  The child may be dead already,
1745                  * in which case setpgid returns error code EACCES. */
1746                 setpgid(child->pid, pi->pgrp);
1747
1748                 if (nextin != 0)
1749                         close(nextin);
1750                 if (nextout != 1)
1751                         close(nextout);
1752
1753                 /* If there isn't another process, nextin is garbage
1754                    but it doesn't matter */
1755                 nextin = pipefds[0];
1756         }
1757 #endif
1758         return -1;
1759 }
1760
1761 static int run_list_real(struct pipe *pi)
1762 {
1763         char *save_name = NULL;
1764         char **list = NULL;
1765         char **save_list = NULL;
1766         struct pipe *rpipe;
1767         int flag_rep = 0;
1768 #ifndef __U_BOOT__
1769         int save_num_progs;
1770 #endif
1771         int rcode=0, flag_skip=1;
1772         int flag_restore = 0;
1773         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1774         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1775         /* check syntax for "for" */
1776         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1777                 if ((rpipe->r_mode == RES_IN ||
1778                     rpipe->r_mode == RES_FOR) &&
1779                     (rpipe->next == NULL)) {
1780                                 syntax();
1781 #ifdef __U_BOOT__
1782                                 flag_repeat = 0;
1783 #endif
1784                                 return 1;
1785                 }
1786                 if ((rpipe->r_mode == RES_IN &&
1787                         (rpipe->next->r_mode == RES_IN &&
1788                         rpipe->next->progs->argv != NULL))||
1789                         (rpipe->r_mode == RES_FOR &&
1790                         rpipe->next->r_mode != RES_IN)) {
1791                                 syntax();
1792 #ifdef __U_BOOT__
1793                                 flag_repeat = 0;
1794 #endif
1795                                 return 1;
1796                 }
1797         }
1798         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1799                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1800                         pi->r_mode == RES_FOR) {
1801 #ifdef __U_BOOT__
1802                                 /* check Ctrl-C */
1803                                 ctrlc();
1804                                 if ((had_ctrlc())) {
1805                                         return 1;
1806                                 }
1807 #endif
1808                                 flag_restore = 0;
1809                                 if (!rpipe) {
1810                                         flag_rep = 0;
1811                                         rpipe = pi;
1812                                 }
1813                 }
1814                 rmode = pi->r_mode;
1815                 debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1816                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1817                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1818                         continue;
1819                 }
1820                 flag_skip = 1;
1821                 skip_more_in_this_rmode = RES_XXXX;
1822                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1823                 if (rmode == RES_THEN &&  if_code) continue;
1824                 if (rmode == RES_ELSE && !if_code) continue;
1825                 if (rmode == RES_ELIF && !if_code) break;
1826                 if (rmode == RES_FOR && pi->num_progs) {
1827                         if (!list) {
1828                                 /* if no variable values after "in" we skip "for" */
1829                                 if (!pi->next->progs->argv) continue;
1830                                 /* create list of variable values */
1831                                 list = make_list_in(pi->next->progs->argv,
1832                                         pi->progs->argv[0]);
1833                                 save_list = list;
1834                                 save_name = pi->progs->argv[0];
1835                                 pi->progs->argv[0] = NULL;
1836                                 flag_rep = 1;
1837                         }
1838                         if (!(*list)) {
1839                                 free(pi->progs->argv[0]);
1840                                 free(save_list);
1841                                 list = NULL;
1842                                 flag_rep = 0;
1843                                 pi->progs->argv[0] = save_name;
1844 #ifndef __U_BOOT__
1845                                 pi->progs->glob_result.gl_pathv[0] =
1846                                         pi->progs->argv[0];
1847 #endif
1848                                 continue;
1849                         } else {
1850                                 /* insert new value from list for variable */
1851                                 if (pi->progs->argv[0])
1852                                         free(pi->progs->argv[0]);
1853                                 pi->progs->argv[0] = *list++;
1854 #ifndef __U_BOOT__
1855                                 pi->progs->glob_result.gl_pathv[0] =
1856                                         pi->progs->argv[0];
1857 #endif
1858                         }
1859                 }
1860                 if (rmode == RES_IN) continue;
1861                 if (rmode == RES_DO) {
1862                         if (!flag_rep) continue;
1863                 }
1864                 if (rmode == RES_DONE) {
1865                         if (flag_rep) {
1866                                 flag_restore = 1;
1867                         } else {
1868                                 rpipe = NULL;
1869                         }
1870                 }
1871                 if (pi->num_progs == 0) continue;
1872 #ifndef __U_BOOT__
1873                 save_num_progs = pi->num_progs; /* save number of programs */
1874 #endif
1875                 rcode = run_pipe_real(pi);
1876                 debug_printf("run_pipe_real returned %d\n",rcode);
1877 #ifndef __U_BOOT__
1878                 if (rcode!=-1) {
1879                         /* We only ran a builtin: rcode was set by the return value
1880                          * of run_pipe_real(), and we don't need to wait for anything. */
1881                 } else if (pi->followup==PIPE_BG) {
1882                         /* XXX check bash's behavior with nontrivial pipes */
1883                         /* XXX compute jobid */
1884                         /* XXX what does bash do with attempts to background builtins? */
1885                         insert_bg_job(pi);
1886                         rcode = EXIT_SUCCESS;
1887                 } else {
1888                         if (interactive) {
1889                                 /* move the new process group into the foreground */
1890                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1891                                         perror_msg("tcsetpgrp-3");
1892                                 rcode = checkjobs(pi);
1893                                 /* move the shell to the foreground */
1894                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1895                                         perror_msg("tcsetpgrp-4");
1896                         } else {
1897                                 rcode = checkjobs(pi);
1898                         }
1899                         debug_printf("checkjobs returned %d\n",rcode);
1900                 }
1901                 last_return_code=rcode;
1902 #else
1903                 if (rcode < -1) {
1904                         last_return_code = -rcode - 2;
1905                         return -2;      /* exit */
1906                 }
1907                 last_return_code=(rcode == 0) ? 0 : 1;
1908 #endif
1909 #ifndef __U_BOOT__
1910                 pi->num_progs = save_num_progs; /* restore number of programs */
1911 #endif
1912                 if ( rmode == RES_IF || rmode == RES_ELIF )
1913                         next_if_code=rcode;  /* can be overwritten a number of times */
1914                 if (rmode == RES_WHILE)
1915                         flag_rep = !last_return_code;
1916                 if (rmode == RES_UNTIL)
1917                         flag_rep = last_return_code;
1918                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1919                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1920                         skip_more_in_this_rmode=rmode;
1921 #ifndef __U_BOOT__
1922                 checkjobs(NULL);
1923 #endif
1924         }
1925         return rcode;
1926 }
1927
1928 /* broken, of course, but OK for testing */
1929 static char *indenter(int i)
1930 {
1931         static char blanks[]="                                    ";
1932         return &blanks[sizeof(blanks)-i-1];
1933 }
1934
1935 /* return code is the exit status of the pipe */
1936 static int free_pipe(struct pipe *pi, int indent)
1937 {
1938         char **p;
1939         struct child_prog *child;
1940 #ifndef __U_BOOT__
1941         struct redir_struct *r, *rnext;
1942 #endif
1943         int a, i, ret_code=0;
1944         char *ind = indenter(indent);
1945
1946 #ifndef __U_BOOT__
1947         if (pi->stopped_progs > 0)
1948                 return ret_code;
1949         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1950 #endif
1951         for (i=0; i<pi->num_progs; i++) {
1952                 child = &pi->progs[i];
1953                 final_printf("%s  command %d:\n",ind,i);
1954                 if (child->argv) {
1955                         for (a=0,p=child->argv; *p; a++,p++) {
1956                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1957                         }
1958 #ifndef __U_BOOT__
1959                         globfree(&child->glob_result);
1960 #else
1961                         for (a = 0; a < child->argc; a++) {
1962                                 free(child->argv[a]);
1963                         }
1964                         free(child->argv);
1965                         free(child->argv_nonnull);
1966                         child->argc = 0;
1967 #endif
1968                         child->argv=NULL;
1969                 } else if (child->group) {
1970 #ifndef __U_BOOT__
1971                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1972 #endif
1973                         ret_code = free_pipe_list(child->group,indent+3);
1974                         final_printf("%s   end group\n",ind);
1975                 } else {
1976                         final_printf("%s   (nil)\n",ind);
1977                 }
1978 #ifndef __U_BOOT__
1979                 for (r=child->redirects; r; r=rnext) {
1980                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1981                         if (r->dup == -1) {
1982                                 /* guard against the case >$FOO, where foo is unset or blank */
1983                                 if (r->word.gl_pathv) {
1984                                         final_printf(" %s\n", *r->word.gl_pathv);
1985                                         globfree(&r->word);
1986                                 }
1987                         } else {
1988                                 final_printf("&%d\n", r->dup);
1989                         }
1990                         rnext=r->next;
1991                         free(r);
1992                 }
1993                 child->redirects=NULL;
1994 #endif
1995         }
1996         free(pi->progs);   /* children are an array, they get freed all at once */
1997         pi->progs=NULL;
1998         return ret_code;
1999 }
2000
2001 static int free_pipe_list(struct pipe *head, int indent)
2002 {
2003         int rcode=0;   /* if list has no members */
2004         struct pipe *pi, *next;
2005         char *ind = indenter(indent);
2006         for (pi=head; pi; pi=next) {
2007                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2008                 rcode = free_pipe(pi, indent);
2009                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2010                 next=pi->next;
2011                 pi->next=NULL;
2012                 free(pi);
2013         }
2014         return rcode;
2015 }
2016
2017 /* Select which version we will use */
2018 static int run_list(struct pipe *pi)
2019 {
2020         int rcode=0;
2021 #ifndef __U_BOOT__
2022         if (fake_mode==0) {
2023 #endif
2024                 rcode = run_list_real(pi);
2025 #ifndef __U_BOOT__
2026         }
2027 #endif
2028         /* free_pipe_list has the side effect of clearing memory
2029          * In the long run that function can be merged with run_list_real,
2030          * but doing that now would hobble the debugging effort. */
2031         free_pipe_list(pi,0);
2032         return rcode;
2033 }
2034
2035 /* The API for glob is arguably broken.  This routine pushes a non-matching
2036  * string into the output structure, removing non-backslashed backslashes.
2037  * If someone can prove me wrong, by performing this function within the
2038  * original glob(3) api, feel free to rewrite this routine into oblivion.
2039  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2040  * XXX broken if the last character is '\\', check that before calling.
2041  */
2042 #ifndef __U_BOOT__
2043 static int globhack(const char *src, int flags, glob_t *pglob)
2044 {
2045         int cnt=0, pathc;
2046         const char *s;
2047         char *dest;
2048         for (cnt=1, s=src; s && *s; s++) {
2049                 if (*s == '\\') s++;
2050                 cnt++;
2051         }
2052         dest = malloc(cnt);
2053         if (!dest) return GLOB_NOSPACE;
2054         if (!(flags & GLOB_APPEND)) {
2055                 pglob->gl_pathv=NULL;
2056                 pglob->gl_pathc=0;
2057                 pglob->gl_offs=0;
2058                 pglob->gl_offs=0;
2059         }
2060         pathc = ++pglob->gl_pathc;
2061         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2062         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2063         pglob->gl_pathv[pathc-1]=dest;
2064         pglob->gl_pathv[pathc]=NULL;
2065         for (s=src; s && *s; s++, dest++) {
2066                 if (*s == '\\') s++;
2067                 *dest = *s;
2068         }
2069         *dest='\0';
2070         return 0;
2071 }
2072
2073 /* XXX broken if the last character is '\\', check that before calling */
2074 static int glob_needed(const char *s)
2075 {
2076         for (; *s; s++) {
2077                 if (*s == '\\') s++;
2078                 if (strchr("*[?",*s)) return 1;
2079         }
2080         return 0;
2081 }
2082
2083 #if 0
2084 static void globprint(glob_t *pglob)
2085 {
2086         int i;
2087         debug_printf("glob_t at %p:\n", pglob);
2088         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2089                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2090         for (i=0; i<pglob->gl_pathc; i++)
2091                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2092                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2093 }
2094 #endif
2095
2096 static int xglob(o_string *dest, int flags, glob_t *pglob)
2097 {
2098         int gr;
2099
2100         /* short-circuit for null word */
2101         /* we can code this better when the debug_printf's are gone */
2102         if (dest->length == 0) {
2103                 if (dest->nonnull) {
2104                         /* bash man page calls this an "explicit" null */
2105                         gr = globhack(dest->data, flags, pglob);
2106                         debug_printf("globhack returned %d\n",gr);
2107                 } else {
2108                         return 0;
2109                 }
2110         } else if (glob_needed(dest->data)) {
2111                 gr = glob(dest->data, flags, NULL, pglob);
2112                 debug_printf("glob returned %d\n",gr);
2113                 if (gr == GLOB_NOMATCH) {
2114                         /* quote removal, or more accurately, backslash removal */
2115                         gr = globhack(dest->data, flags, pglob);
2116                         debug_printf("globhack returned %d\n",gr);
2117                 }
2118         } else {
2119                 gr = globhack(dest->data, flags, pglob);
2120                 debug_printf("globhack returned %d\n",gr);
2121         }
2122         if (gr == GLOB_NOSPACE)
2123                 error_msg_and_die("out of memory during glob");
2124         if (gr != 0) { /* GLOB_ABORTED ? */
2125                 error_msg("glob(3) error %d",gr);
2126         }
2127         /* globprint(glob_target); */
2128         return gr;
2129 }
2130 #endif
2131
2132 #ifdef __U_BOOT__
2133 static char *get_dollar_var(char ch);
2134 #endif
2135
2136 /* This is used to get/check local shell variables */
2137 char *get_local_var(const char *s)
2138 {
2139         struct variables *cur;
2140
2141         if (!s)
2142                 return NULL;
2143
2144 #ifdef __U_BOOT__
2145         if (*s == '$')
2146                 return get_dollar_var(s[1]);
2147 #endif
2148
2149         for (cur = top_vars; cur; cur=cur->next)
2150                 if(strcmp(cur->name, s)==0)
2151                         return cur->value;
2152         return NULL;
2153 }
2154
2155 /* This is used to set local shell variables
2156    flg_export==0 if only local (not exporting) variable
2157    flg_export==1 if "new" exporting environ
2158    flg_export>1  if current startup environ (not call putenv()) */
2159 int set_local_var(const char *s, int flg_export)
2160 {
2161         char *name, *value;
2162         int result=0;
2163         struct variables *cur;
2164
2165 #ifdef __U_BOOT__
2166         /* might be possible! */
2167         if (!isalpha(*s))
2168                 return -1;
2169 #endif
2170
2171         name=strdup(s);
2172
2173 #ifdef __U_BOOT__
2174         if (env_get(name) != NULL) {
2175                 printf ("ERROR: "
2176                                 "There is a global environment variable with the same name.\n");
2177                 free(name);
2178                 return -1;
2179         }
2180 #endif
2181         /* Assume when we enter this function that we are already in
2182          * NAME=VALUE format.  So the first order of business is to
2183          * split 's' on the '=' into 'name' and 'value' */
2184         value = strchr(name, '=');
2185         if (value == NULL || *(value + 1) == 0) {
2186                 free(name);
2187                 return -1;
2188         }
2189         *value++ = 0;
2190
2191         for(cur = top_vars; cur; cur = cur->next) {
2192                 if(strcmp(cur->name, name)==0)
2193                         break;
2194         }
2195
2196         if(cur) {
2197                 if(strcmp(cur->value, value)==0) {
2198                         if(flg_export>0 && cur->flg_export==0)
2199                                 cur->flg_export=flg_export;
2200                         else
2201                                 result++;
2202                 } else {
2203                         if(cur->flg_read_only) {
2204                                 error_msg("%s: readonly variable", name);
2205                                 result = -1;
2206                         } else {
2207                                 if(flg_export>0 || cur->flg_export>1)
2208                                         cur->flg_export=1;
2209                                 free(cur->value);
2210
2211                                 cur->value = strdup(value);
2212                         }
2213                 }
2214         } else {
2215                 cur = malloc(sizeof(struct variables));
2216                 if(!cur) {
2217                         result = -1;
2218                 } else {
2219                         cur->name = strdup(name);
2220                         if (cur->name == NULL) {
2221                                 free(cur);
2222                                 result = -1;
2223                         } else {
2224                                 struct variables *bottom = top_vars;
2225                                 cur->value = strdup(value);
2226                                 cur->next = NULL;
2227                                 cur->flg_export = flg_export;
2228                                 cur->flg_read_only = 0;
2229                                 while(bottom->next) bottom=bottom->next;
2230                                 bottom->next = cur;
2231                         }
2232                 }
2233         }
2234
2235 #ifndef __U_BOOT__
2236         if(result==0 && cur->flg_export==1) {
2237                 *(value-1) = '=';
2238                 result = putenv(name);
2239         } else {
2240 #endif
2241                 free(name);
2242 #ifndef __U_BOOT__
2243                 if(result>0)            /* equivalent to previous set */
2244                         result = 0;
2245         }
2246 #endif
2247         return result;
2248 }
2249
2250 void unset_local_var(const char *name)
2251 {
2252         struct variables *cur;
2253
2254         if (name) {
2255                 for (cur = top_vars; cur; cur=cur->next) {
2256                         if(strcmp(cur->name, name)==0)
2257                                 break;
2258                 }
2259                 if (cur != NULL) {
2260                         struct variables *next = top_vars;
2261                         if(cur->flg_read_only) {
2262                                 error_msg("%s: readonly variable", name);
2263                                 return;
2264                         } else {
2265 #ifndef __U_BOOT__
2266                                 if(cur->flg_export)
2267                                         unenv_set(cur->name);
2268 #endif
2269                                 free(cur->name);
2270                                 free(cur->value);
2271                                 while (next->next != cur)
2272                                         next = next->next;
2273                                 next->next = cur->next;
2274                         }
2275                         free(cur);
2276                 }
2277         }
2278 }
2279
2280 static int is_assignment(const char *s)
2281 {
2282         if (s == NULL)
2283                 return 0;
2284
2285         if (!isalpha(*s)) return 0;
2286         ++s;
2287         while(isalnum(*s) || *s=='_') ++s;
2288         return *s=='=';
2289 }
2290
2291 #ifndef __U_BOOT__
2292 /* the src parameter allows us to peek forward to a possible &n syntax
2293  * for file descriptor duplication, e.g., "2>&1".
2294  * Return code is 0 normally, 1 if a syntax error is detected in src.
2295  * Resource errors (in xmalloc) cause the process to exit */
2296 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2297         struct in_str *input)
2298 {
2299         struct child_prog *child=ctx->child;
2300         struct redir_struct *redir = child->redirects;
2301         struct redir_struct *last_redir=NULL;
2302
2303         /* Create a new redir_struct and drop it onto the end of the linked list */
2304         while(redir) {
2305                 last_redir=redir;
2306                 redir=redir->next;
2307         }
2308         redir = xmalloc(sizeof(struct redir_struct));
2309         redir->next=NULL;
2310         redir->word.gl_pathv=NULL;
2311         if (last_redir) {
2312                 last_redir->next=redir;
2313         } else {
2314                 child->redirects=redir;
2315         }
2316
2317         redir->type=style;
2318         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2319
2320         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2321
2322         /* Check for a '2>&1' type redirect */
2323         redir->dup = redirect_dup_num(input);
2324         if (redir->dup == -2) return 1;  /* syntax error */
2325         if (redir->dup != -1) {
2326                 /* Erik had a check here that the file descriptor in question
2327                  * is legit; I postpone that to "run time"
2328                  * A "-" representation of "close me" shows up as a -3 here */
2329                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2330         } else {
2331                 /* We do _not_ try to open the file that src points to,
2332                  * since we need to return and let src be expanded first.
2333                  * Set ctx->pending_redirect, so we know what to do at the
2334                  * end of the next parsed word.
2335                  */
2336                 ctx->pending_redirect = redir;
2337         }
2338         return 0;
2339 }
2340 #endif
2341
2342 static struct pipe *new_pipe(void)
2343 {
2344         struct pipe *pi;
2345         pi = xmalloc(sizeof(struct pipe));
2346         pi->num_progs = 0;
2347         pi->progs = NULL;
2348         pi->next = NULL;
2349         pi->followup = 0;  /* invalid */
2350         pi->r_mode = RES_NONE;
2351         return pi;
2352 }
2353
2354 static void initialize_context(struct p_context *ctx)
2355 {
2356         ctx->pipe=NULL;
2357 #ifndef __U_BOOT__
2358         ctx->pending_redirect=NULL;
2359 #endif
2360         ctx->child=NULL;
2361         ctx->list_head=new_pipe();
2362         ctx->pipe=ctx->list_head;
2363         ctx->w=RES_NONE;
2364         ctx->stack=NULL;
2365 #ifdef __U_BOOT__
2366         ctx->old_flag=0;
2367 #endif
2368         done_command(ctx);   /* creates the memory for working child */
2369 }
2370
2371 /* normal return is 0
2372  * if a reserved word is found, and processed, return 1
2373  * should handle if, then, elif, else, fi, for, while, until, do, done.
2374  * case, function, and select are obnoxious, save those for later.
2375  */
2376 struct reserved_combo {
2377         char *literal;
2378         int code;
2379         long flag;
2380 };
2381 /* Mostly a list of accepted follow-up reserved words.
2382  * FLAG_END means we are done with the sequence, and are ready
2383  * to turn the compound list into a command.
2384  * FLAG_START means the word must start a new compound list.
2385  */
2386 static struct reserved_combo reserved_list[] = {
2387         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2388         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2389         { "elif",  RES_ELIF,  FLAG_THEN },
2390         { "else",  RES_ELSE,  FLAG_FI   },
2391         { "fi",    RES_FI,    FLAG_END  },
2392         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2393         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2394         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2395         { "in",    RES_IN,    FLAG_DO   },
2396         { "do",    RES_DO,    FLAG_DONE },
2397         { "done",  RES_DONE,  FLAG_END  }
2398 };
2399 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2400
2401 static int reserved_word(o_string *dest, struct p_context *ctx)
2402 {
2403         struct reserved_combo *r;
2404         for (r=reserved_list;
2405                 r<reserved_list+NRES; r++) {
2406                 if (strcmp(dest->data, r->literal) == 0) {
2407                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2408                         if (r->flag & FLAG_START) {
2409                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2410                                 debug_printf("push stack\n");
2411                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2412                                         syntax();
2413                                         free(new);
2414                                         ctx->w = RES_SNTX;
2415                                         b_reset(dest);
2416                                         return 1;
2417                                 }
2418                                 *new = *ctx;   /* physical copy */
2419                                 initialize_context(ctx);
2420                                 ctx->stack=new;
2421                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2422                                 syntax();
2423                                 ctx->w = RES_SNTX;
2424                                 b_reset(dest);
2425                                 return 1;
2426                         }
2427                         ctx->w=r->code;
2428                         ctx->old_flag = r->flag;
2429                         if (ctx->old_flag & FLAG_END) {
2430                                 struct p_context *old;
2431                                 debug_printf("pop stack\n");
2432                                 done_pipe(ctx,PIPE_SEQ);
2433                                 old = ctx->stack;
2434                                 old->child->group = ctx->list_head;
2435 #ifndef __U_BOOT__
2436                                 old->child->subshell = 0;
2437 #endif
2438                                 *ctx = *old;   /* physical copy */
2439                                 free(old);
2440                         }
2441                         b_reset (dest);
2442                         return 1;
2443                 }
2444         }
2445         return 0;
2446 }
2447
2448 /* normal return is 0.
2449  * Syntax or xglob errors return 1. */
2450 static int done_word(o_string *dest, struct p_context *ctx)
2451 {
2452         struct child_prog *child=ctx->child;
2453 #ifndef __U_BOOT__
2454         glob_t *glob_target;
2455         int gr, flags = 0;
2456 #else
2457         char *str, *s;
2458         int argc, cnt;
2459 #endif
2460
2461         debug_printf("done_word: %s %p\n", dest->data, child);
2462         if (dest->length == 0 && !dest->nonnull) {
2463                 debug_printf("  true null, ignored\n");
2464                 return 0;
2465         }
2466 #ifndef __U_BOOT__
2467         if (ctx->pending_redirect) {
2468                 glob_target = &ctx->pending_redirect->word;
2469         } else {
2470 #endif
2471                 if (child->group) {
2472                         syntax();
2473                         return 1;  /* syntax error, groups and arglists don't mix */
2474                 }
2475                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2476                         debug_printf("checking %s for reserved-ness\n",dest->data);
2477                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2478                 }
2479 #ifndef __U_BOOT__
2480                 glob_target = &child->glob_result;
2481                 if (child->argv) flags |= GLOB_APPEND;
2482 #else
2483                 for (cnt = 1, s = dest->data; s && *s; s++) {
2484                         if (*s == '\\') s++;
2485                         cnt++;
2486                 }
2487                 str = malloc(cnt);
2488                 if (!str) return 1;
2489                 if ( child->argv == NULL) {
2490                         child->argc=0;
2491                 }
2492                 argc = ++child->argc;
2493                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2494                 if (child->argv == NULL) {
2495                         free(str);
2496                         return 1;
2497                 }
2498                 child->argv_nonnull = realloc(child->argv_nonnull,
2499                                         (argc+1)*sizeof(*child->argv_nonnull));
2500                 if (child->argv_nonnull == NULL) {
2501                         free(str);
2502                         return 1;
2503                 }
2504                 child->argv[argc-1]=str;
2505                 child->argv_nonnull[argc-1] = dest->nonnull;
2506                 child->argv[argc]=NULL;
2507                 child->argv_nonnull[argc] = 0;
2508                 for (s = dest->data; s && *s; s++,str++) {
2509                         if (*s == '\\') s++;
2510                         *str = *s;
2511                 }
2512                 *str = '\0';
2513 #endif
2514 #ifndef __U_BOOT__
2515         }
2516         gr = xglob(dest, flags, glob_target);
2517         if (gr != 0) return 1;
2518 #endif
2519
2520         b_reset(dest);
2521 #ifndef __U_BOOT__
2522         if (ctx->pending_redirect) {
2523                 ctx->pending_redirect=NULL;
2524                 if (glob_target->gl_pathc != 1) {
2525                         error_msg("ambiguous redirect");
2526                         return 1;
2527                 }
2528         } else {
2529                 child->argv = glob_target->gl_pathv;
2530         }
2531 #endif
2532         if (ctx->w == RES_FOR) {
2533                 done_word(dest,ctx);
2534                 done_pipe(ctx,PIPE_SEQ);
2535         }
2536         return 0;
2537 }
2538
2539 /* The only possible error here is out of memory, in which case
2540  * xmalloc exits. */
2541 static int done_command(struct p_context *ctx)
2542 {
2543         /* The child is really already in the pipe structure, so
2544          * advance the pipe counter and make a new, null child.
2545          * Only real trickiness here is that the uncommitted
2546          * child structure, to which ctx->child points, is not
2547          * counted in pi->num_progs. */
2548         struct pipe *pi=ctx->pipe;
2549         struct child_prog *prog=ctx->child;
2550
2551         if (prog && prog->group == NULL
2552                  && prog->argv == NULL
2553 #ifndef __U_BOOT__
2554                  && prog->redirects == NULL) {
2555 #else
2556                                                                                 ) {
2557 #endif
2558                 debug_printf("done_command: skipping null command\n");
2559                 return 0;
2560         } else if (prog) {
2561                 pi->num_progs++;
2562                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2563         } else {
2564                 debug_printf("done_command: initializing\n");
2565         }
2566         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2567
2568         prog = pi->progs + pi->num_progs;
2569 #ifndef __U_BOOT__
2570         prog->redirects = NULL;
2571 #endif
2572         prog->argv = NULL;
2573         prog->argv_nonnull = NULL;
2574 #ifndef __U_BOOT__
2575         prog->is_stopped = 0;
2576 #endif
2577         prog->group = NULL;
2578 #ifndef __U_BOOT__
2579         prog->glob_result.gl_pathv = NULL;
2580         prog->family = pi;
2581 #endif
2582         prog->sp = 0;
2583         ctx->child = prog;
2584         prog->type = ctx->type;
2585
2586         /* but ctx->pipe and ctx->list_head remain unchanged */
2587         return 0;
2588 }
2589
2590 static int done_pipe(struct p_context *ctx, pipe_style type)
2591 {
2592         struct pipe *new_p;
2593         done_command(ctx);  /* implicit closure of previous command */
2594         debug_printf("done_pipe, type %d\n", type);
2595         ctx->pipe->followup = type;
2596         ctx->pipe->r_mode = ctx->w;
2597         new_p=new_pipe();
2598         ctx->pipe->next = new_p;
2599         ctx->pipe = new_p;
2600         ctx->child = NULL;
2601         done_command(ctx);  /* set up new pipe to accept commands */
2602         return 0;
2603 }
2604
2605 #ifndef __U_BOOT__
2606 /* peek ahead in the in_str to find out if we have a "&n" construct,
2607  * as in "2>&1", that represents duplicating a file descriptor.
2608  * returns either -2 (syntax error), -1 (no &), or the number found.
2609  */
2610 static int redirect_dup_num(struct in_str *input)
2611 {
2612         int ch, d=0, ok=0;
2613         ch = b_peek(input);
2614         if (ch != '&') return -1;
2615
2616         b_getch(input);  /* get the & */
2617         ch=b_peek(input);
2618         if (ch == '-') {
2619                 b_getch(input);
2620                 return -3;  /* "-" represents "close me" */
2621         }
2622         while (isdigit(ch)) {
2623                 d = d*10+(ch-'0');
2624                 ok=1;
2625                 b_getch(input);
2626                 ch = b_peek(input);
2627         }
2628         if (ok) return d;
2629
2630         error_msg("ambiguous redirect");
2631         return -2;
2632 }
2633
2634 /* If a redirect is immediately preceded by a number, that number is
2635  * supposed to tell which file descriptor to redirect.  This routine
2636  * looks for such preceding numbers.  In an ideal world this routine
2637  * needs to handle all the following classes of redirects...
2638  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2639  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2640  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2641  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2642  * A -1 output from this program means no valid number was found, so the
2643  * caller should use the appropriate default for this redirection.
2644  */
2645 static int redirect_opt_num(o_string *o)
2646 {
2647         int num;
2648
2649         if (o->length==0) return -1;
2650         for(num=0; num<o->length; num++) {
2651                 if (!isdigit(*(o->data+num))) {
2652                         return -1;
2653                 }
2654         }
2655         /* reuse num (and save an int) */
2656         num=atoi(o->data);
2657         b_reset(o);
2658         return num;
2659 }
2660
2661 FILE *generate_stream_from_list(struct pipe *head)
2662 {
2663         FILE *pf;
2664 #if 1
2665         int pid, channel[2];
2666         if (pipe(channel)<0) perror_msg_and_die("pipe");
2667         pid=fork();
2668         if (pid<0) {
2669                 perror_msg_and_die("fork");
2670         } else if (pid==0) {
2671                 close(channel[0]);
2672                 if (channel[1] != 1) {
2673                         dup2(channel[1],1);
2674                         close(channel[1]);
2675                 }
2676 #if 0
2677 #define SURROGATE "surrogate response"
2678                 write(1,SURROGATE,sizeof(SURROGATE));
2679                 _exit(run_list(head));
2680 #else
2681                 _exit(run_list_real(head));   /* leaks memory */
2682 #endif
2683         }
2684         debug_printf("forked child %d\n",pid);
2685         close(channel[1]);
2686         pf = fdopen(channel[0],"r");
2687         debug_printf("pipe on FILE *%p\n",pf);
2688 #else
2689         free_pipe_list(head,0);
2690         pf=popen("echo surrogate response","r");
2691         debug_printf("started fake pipe on FILE *%p\n",pf);
2692 #endif
2693         return pf;
2694 }
2695
2696 /* this version hacked for testing purposes */
2697 /* return code is exit status of the process that is run. */
2698 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2699 {
2700         int retcode;
2701         o_string result=NULL_O_STRING;
2702         struct p_context inner;
2703         FILE *p;
2704         struct in_str pipe_str;
2705         initialize_context(&inner);
2706
2707         /* recursion to generate command */
2708         retcode = parse_stream(&result, &inner, input, subst_end);
2709         if (retcode != 0) return retcode;  /* syntax error or EOF */
2710         done_word(&result, &inner);
2711         done_pipe(&inner, PIPE_SEQ);
2712         b_free(&result);
2713
2714         p=generate_stream_from_list(inner.list_head);
2715         if (p==NULL) return 1;
2716         mark_open(fileno(p));
2717         setup_file_in_str(&pipe_str, p);
2718
2719         /* now send results of command back into original context */
2720         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2721         /* XXX In case of a syntax error, should we try to kill the child?
2722          * That would be tough to do right, so just read until EOF. */
2723         if (retcode == 1) {
2724                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2725         }
2726
2727         debug_printf("done reading from pipe, pclose()ing\n");
2728         /* This is the step that wait()s for the child.  Should be pretty
2729          * safe, since we just read an EOF from its stdout.  We could try
2730          * to better, by using wait(), and keeping track of background jobs
2731          * at the same time.  That would be a lot of work, and contrary
2732          * to the KISS philosophy of this program. */
2733         mark_closed(fileno(p));
2734         retcode=pclose(p);
2735         free_pipe_list(inner.list_head,0);
2736         debug_printf("pclosed, retcode=%d\n",retcode);
2737         /* XXX this process fails to trim a single trailing newline */
2738         return retcode;
2739 }
2740
2741 static int parse_group(o_string *dest, struct p_context *ctx,
2742         struct in_str *input, int ch)
2743 {
2744         int rcode, endch=0;
2745         struct p_context sub;
2746         struct child_prog *child = ctx->child;
2747         if (child->argv) {
2748                 syntax();
2749                 return 1;  /* syntax error, groups and arglists don't mix */
2750         }
2751         initialize_context(&sub);
2752         switch(ch) {
2753                 case '(': endch=')'; child->subshell=1; break;
2754                 case '{': endch='}'; break;
2755                 default: syntax();   /* really logic error */
2756         }
2757         rcode=parse_stream(dest,&sub,input,endch);
2758         done_word(dest,&sub); /* finish off the final word in the subcontext */
2759         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2760         child->group = sub.list_head;
2761         return rcode;
2762         /* child remains "open", available for possible redirects */
2763 }
2764 #endif
2765
2766 /* basically useful version until someone wants to get fancier,
2767  * see the bash man page under "Parameter Expansion" */
2768 static char *lookup_param(char *src)
2769 {
2770         char *p;
2771         char *sep;
2772         char *default_val = NULL;
2773         int assign = 0;
2774         int expand_empty = 0;
2775
2776         if (!src)
2777                 return NULL;
2778
2779         sep = strchr(src, ':');
2780
2781         if (sep) {
2782                 *sep = '\0';
2783                 if (*(sep + 1) == '-')
2784                         default_val = sep+2;
2785                 if (*(sep + 1) == '=') {
2786                         default_val = sep+2;
2787                         assign = 1;
2788                 }
2789                 if (*(sep + 1) == '+') {
2790                         default_val = sep+2;
2791                         expand_empty = 1;
2792                 }
2793         }
2794
2795         p = env_get(src);
2796         if (!p)
2797                 p = get_local_var(src);
2798
2799         if (!p || strlen(p) == 0) {
2800                 p = default_val;
2801                 if (assign) {
2802                         char *var = malloc(strlen(src)+strlen(default_val)+2);
2803                         if (var) {
2804                                 sprintf(var, "%s=%s", src, default_val);
2805                                 set_local_var(var, 0);
2806                         }
2807                         free(var);
2808                 }
2809         } else if (expand_empty) {
2810                 p += strlen(p);
2811         }
2812
2813         if (sep)
2814                 *sep = ':';
2815
2816         return p;
2817 }
2818
2819 #ifdef __U_BOOT__
2820 static char *get_dollar_var(char ch)
2821 {
2822         static char buf[40];
2823
2824         buf[0] = '\0';
2825         switch (ch) {
2826                 case '?':
2827                         sprintf(buf, "%u", (unsigned int)last_return_code);
2828                         break;
2829                 default:
2830                         return NULL;
2831         }
2832         return buf;
2833 }
2834 #endif
2835
2836 /* return code: 0 for OK, 1 for syntax error */
2837 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2838 {
2839 #ifndef __U_BOOT__
2840         int i, advance=0;
2841 #else
2842         int advance=0;
2843 #endif
2844 #ifndef __U_BOOT__
2845         char sep[]=" ";
2846 #endif
2847         int ch = input->peek(input);  /* first character after the $ */
2848         debug_printf("handle_dollar: ch=%c\n",ch);
2849         if (isalpha(ch)) {
2850                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851                 ctx->child->sp++;
2852                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2853                         b_getch(input);
2854                         b_addchr(dest,ch);
2855                 }
2856                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2857 #ifndef __U_BOOT__
2858         } else if (isdigit(ch)) {
2859                 i = ch-'0';  /* XXX is $0 special? */
2860                 if (i<global_argc) {
2861                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2862                 }
2863                 advance = 1;
2864 #endif
2865         } else switch (ch) {
2866 #ifndef __U_BOOT__
2867                 case '$':
2868                         b_adduint(dest,getpid());
2869                         advance = 1;
2870                         break;
2871                 case '!':
2872                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2873                         advance = 1;
2874                         break;
2875 #endif
2876                 case '?':
2877 #ifndef __U_BOOT__
2878                         b_adduint(dest,last_return_code);
2879 #else
2880                         ctx->child->sp++;
2881                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2882                         b_addchr(dest, '$');
2883                         b_addchr(dest, '?');
2884                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2885 #endif
2886                         advance = 1;
2887                         break;
2888 #ifndef __U_BOOT__
2889                 case '#':
2890                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2891                         advance = 1;
2892                         break;
2893 #endif
2894                 case '{':
2895                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2896                         ctx->child->sp++;
2897                         b_getch(input);
2898                         /* XXX maybe someone will try to escape the '}' */
2899                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2900                                 b_addchr(dest,ch);
2901                         }
2902                         if (ch != '}') {
2903                                 syntax();
2904                                 return 1;
2905                         }
2906                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2907                         break;
2908 #ifndef __U_BOOT__
2909                 case '(':
2910                         b_getch(input);
2911                         process_command_subs(dest, ctx, input, ')');
2912                         break;
2913                 case '*':
2914                         sep[0]=ifs[0];
2915                         for (i=1; i<global_argc; i++) {
2916                                 parse_string(dest, ctx, global_argv[i]);
2917                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2918                         }
2919                         break;
2920                 case '@':
2921                 case '-':
2922                 case '_':
2923                         /* still unhandled, but should be eventually */
2924                         error_msg("unhandled syntax: $%c",ch);
2925                         return 1;
2926                         break;
2927 #endif
2928                 default:
2929                         b_addqchr(dest,'$',dest->quote);
2930         }
2931         /* Eat the character if the flag was set.  If the compiler
2932          * is smart enough, we could substitute "b_getch(input);"
2933          * for all the "advance = 1;" above, and also end up with
2934          * a nice size-optimized program.  Hah!  That'll be the day.
2935          */
2936         if (advance) b_getch(input);
2937         return 0;
2938 }
2939
2940 #ifndef __U_BOOT__
2941 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2942 {
2943         struct in_str foo;
2944         setup_string_in_str(&foo, src);
2945         return parse_stream(dest, ctx, &foo, '\0');
2946 }
2947 #endif
2948
2949 /* return code is 0 for normal exit, 1 for syntax error */
2950 static int parse_stream(o_string *dest, struct p_context *ctx,
2951                         struct in_str *input, int end_trigger)
2952 {
2953         unsigned int ch, m;
2954 #ifndef __U_BOOT__
2955         int redir_fd;
2956         redir_type redir_style;
2957 #endif
2958         int next;
2959
2960         /* Only double-quote state is handled in the state variable dest->quote.
2961          * A single-quote triggers a bypass of the main loop until its mate is
2962          * found.  When recursing, quote state is passed in via dest->quote. */
2963
2964         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2965         while ((ch=b_getch(input))!=EOF) {
2966                 m = map[ch];
2967 #ifdef __U_BOOT__
2968                 if (input->__promptme == 0) return 1;
2969 #endif
2970                 next = (ch == '\n') ? 0 : b_peek(input);
2971
2972                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2973                         ch >= ' ' ? ch : '.', ch, m,
2974                         dest->quote, ctx->stack == NULL ? '*' : '.');
2975
2976                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2977                         b_addqchr(dest, ch, dest->quote);
2978                 } else {
2979                         if (m==2) {  /* unquoted IFS */
2980                                 if (done_word(dest, ctx)) {
2981                                         return 1;
2982                                 }
2983                                 /* If we aren't performing a substitution, treat a newline as a
2984                                  * command separator.  */
2985                                 if (end_trigger != '\0' && ch=='\n')
2986                                         done_pipe(ctx,PIPE_SEQ);
2987                         }
2988                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2989                                 debug_printf("leaving parse_stream (triggered)\n");
2990                                 return 0;
2991                         }
2992 #if 0
2993                         if (ch=='\n') {
2994                                 /* Yahoo!  Time to run with it! */
2995                                 done_pipe(ctx,PIPE_SEQ);
2996                                 run_list(ctx->list_head);
2997                                 initialize_context(ctx);
2998                         }
2999 #endif
3000                         if (m!=2) switch (ch) {
3001                 case '#':
3002                         if (dest->length == 0 && !dest->quote) {
3003                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
3004                         } else {
3005                                 b_addqchr(dest, ch, dest->quote);
3006                         }
3007                         break;
3008                 case '\\':
3009                         if (next == EOF) {
3010                                 syntax();
3011                                 return 1;
3012                         }
3013                         b_addqchr(dest, '\\', dest->quote);
3014                         b_addqchr(dest, b_getch(input), dest->quote);
3015                         break;
3016                 case '$':
3017                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3018                         break;
3019                 case '\'':
3020                         dest->nonnull = 1;
3021                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3022 #ifdef __U_BOOT__
3023                                 if(input->__promptme == 0) return 1;
3024 #endif
3025                                 b_addchr(dest,ch);
3026                         }
3027                         if (ch==EOF) {
3028                                 syntax();
3029                                 return 1;
3030                         }
3031                         break;
3032                 case '"':
3033                         dest->nonnull = 1;
3034                         dest->quote = !dest->quote;
3035                         break;
3036 #ifndef __U_BOOT__
3037                 case '`':
3038                         process_command_subs(dest, ctx, input, '`');
3039                         break;
3040                 case '>':
3041                         redir_fd = redirect_opt_num(dest);
3042                         done_word(dest, ctx);
3043                         redir_style=REDIRECT_OVERWRITE;
3044                         if (next == '>') {
3045                                 redir_style=REDIRECT_APPEND;
3046                                 b_getch(input);
3047                         } else if (next == '(') {
3048                                 syntax();   /* until we support >(list) Process Substitution */
3049                                 return 1;
3050                         }
3051                         setup_redirect(ctx, redir_fd, redir_style, input);
3052                         break;
3053                 case '<':
3054                         redir_fd = redirect_opt_num(dest);
3055                         done_word(dest, ctx);
3056                         redir_style=REDIRECT_INPUT;
3057                         if (next == '<') {
3058                                 redir_style=REDIRECT_HEREIS;
3059                                 b_getch(input);
3060                         } else if (next == '>') {
3061                                 redir_style=REDIRECT_IO;
3062                                 b_getch(input);
3063                         } else if (next == '(') {
3064                                 syntax();   /* until we support <(list) Process Substitution */
3065                                 return 1;
3066                         }
3067                         setup_redirect(ctx, redir_fd, redir_style, input);
3068                         break;
3069 #endif
3070                 case ';':
3071                         done_word(dest, ctx);
3072                         done_pipe(ctx,PIPE_SEQ);
3073                         break;
3074                 case '&':
3075                         done_word(dest, ctx);
3076                         if (next=='&') {
3077                                 b_getch(input);
3078                                 done_pipe(ctx,PIPE_AND);
3079                         } else {
3080 #ifndef __U_BOOT__
3081                                 done_pipe(ctx,PIPE_BG);
3082 #else
3083                                 syntax_err();
3084                                 return 1;
3085 #endif
3086                         }
3087                         break;
3088                 case '|':
3089                         done_word(dest, ctx);
3090                         if (next=='|') {
3091                                 b_getch(input);
3092                                 done_pipe(ctx,PIPE_OR);
3093                         } else {
3094                                 /* we could pick up a file descriptor choice here
3095                                  * with redirect_opt_num(), but bash doesn't do it.
3096                                  * "echo foo 2| cat" yields "foo 2". */
3097 #ifndef __U_BOOT__
3098                                 done_command(ctx);
3099 #else
3100                                 syntax_err();
3101                                 return 1;
3102 #endif
3103                         }
3104                         break;
3105 #ifndef __U_BOOT__
3106                 case '(':
3107                 case '{':
3108                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3109                         break;
3110                 case ')':
3111                 case '}':
3112                         syntax();   /* Proper use of this character caught by end_trigger */
3113                         return 1;
3114                         break;
3115 #endif
3116                 case SUBSTED_VAR_SYMBOL:
3117                         dest->nonnull = 1;
3118                         while (ch = b_getch(input), ch != EOF &&
3119                             ch != SUBSTED_VAR_SYMBOL) {
3120                                 debug_printf("subst, pass=%d\n", ch);
3121                                 if (input->__promptme == 0)
3122                                         return 1;
3123                                 b_addchr(dest, ch);
3124                         }
3125                         debug_printf("subst, term=%d\n", ch);
3126                         if (ch == EOF) {
3127                                 syntax();
3128                                 return 1;
3129                         }
3130                         break;
3131                 default:
3132                         syntax();   /* this is really an internal logic error */
3133                         return 1;
3134                         }
3135                 }
3136         }
3137         /* complain if quote?  No, maybe we just finished a command substitution
3138          * that was quoted.  Example:
3139          * $ echo "`cat foo` plus more"
3140          * and we just got the EOF generated by the subshell that ran "cat foo"
3141          * The only real complaint is if we got an EOF when end_trigger != '\0',
3142          * that is, we were really supposed to get end_trigger, and never got
3143          * one before the EOF.  Can't use the standard "syntax error" return code,
3144          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3145         debug_printf("leaving parse_stream (EOF)\n");
3146         if (end_trigger != '\0') return -1;
3147         return 0;
3148 }
3149
3150 static void mapset(const unsigned char *set, int code)
3151 {
3152         const unsigned char *s;
3153         for (s=set; *s; s++) map[*s] = code;
3154 }
3155
3156 static void update_ifs_map(void)
3157 {
3158         /* char *ifs and char map[256] are both globals. */
3159         ifs = (uchar *)env_get("IFS");
3160         if (ifs == NULL) ifs=(uchar *)" \t\n";
3161         /* Precompute a list of 'flow through' behavior so it can be treated
3162          * quickly up front.  Computation is necessary because of IFS.
3163          * Special case handling of IFS == " \t\n" is not implemented.
3164          * The map[] array only really needs two bits each, and on most machines
3165          * that would be faster because of the reduced L1 cache footprint.
3166          */
3167         memset(map,0,sizeof(map)); /* most characters flow through always */
3168 #ifndef __U_BOOT__
3169         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3170         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3171 #else
3172         {
3173                 uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3174                 mapset(subst, 3);       /* never flow through */
3175         }
3176         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3177         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3178 #endif
3179         mapset(ifs, 2);            /* also flow through if quoted */
3180 }
3181
3182 /* most recursion does not come through here, the exeception is
3183  * from builtin_source() */
3184 static int parse_stream_outer(struct in_str *inp, int flag)
3185 {
3186
3187         struct p_context ctx;
3188         o_string temp=NULL_O_STRING;
3189         int rcode;
3190 #ifdef __U_BOOT__
3191         int code = 1;
3192 #endif
3193         do {
3194                 ctx.type = flag;
3195                 initialize_context(&ctx);
3196                 update_ifs_map();
3197                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3198                 inp->promptmode=1;
3199                 rcode = parse_stream(&temp, &ctx, inp,
3200                                      flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n');
3201 #ifdef __U_BOOT__
3202                 if (rcode == 1) flag_repeat = 0;
3203 #endif
3204                 if (rcode != 1 && ctx.old_flag != 0) {
3205                         syntax();
3206 #ifdef __U_BOOT__
3207                         flag_repeat = 0;
3208 #endif
3209                 }
3210                 if (rcode != 1 && ctx.old_flag == 0) {
3211                         done_word(&temp, &ctx);
3212                         done_pipe(&ctx,PIPE_SEQ);
3213 #ifndef __U_BOOT__
3214                         run_list(ctx.list_head);
3215 #else
3216                         code = run_list(ctx.list_head);
3217                         if (code == -2) {       /* exit */
3218                                 b_free(&temp);
3219                                 code = 0;
3220                                 /* XXX hackish way to not allow exit from main loop */
3221                                 if (inp->peek == file_peek) {
3222                                         printf("exit not allowed from main input shell.\n");
3223                                         continue;
3224                                 }
3225                                 break;
3226                         }
3227                         if (code == -1)
3228                             flag_repeat = 0;
3229 #endif
3230                 } else {
3231                         if (ctx.old_flag != 0) {
3232                                 free(ctx.stack);
3233                                 b_reset(&temp);
3234                         }
3235 #ifdef __U_BOOT__
3236                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3237                         inp->__promptme = 1;
3238 #endif
3239                         temp.nonnull = 0;
3240                         temp.quote = 0;
3241                         inp->p = NULL;
3242                         free_pipe_list(ctx.list_head,0);
3243                 }
3244                 b_free(&temp);
3245         /* loop on syntax errors, return on EOF */
3246         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP) &&
3247                 (inp->peek != static_peek || b_peek(inp)));
3248 #ifndef __U_BOOT__
3249         return 0;
3250 #else
3251         return (code != 0) ? 1 : 0;
3252 #endif /* __U_BOOT__ */
3253 }
3254
3255 #ifndef __U_BOOT__
3256 static int parse_string_outer(const char *s, int flag)
3257 #else
3258 int parse_string_outer(const char *s, int flag)
3259 #endif  /* __U_BOOT__ */
3260 {
3261         struct in_str input;
3262 #ifdef __U_BOOT__
3263         char *p = NULL;
3264         int rcode;
3265         if (!s)
3266                 return 1;
3267         if (!*s)
3268                 return 0;
3269         if (!(p = strchr(s, '\n')) || *++p) {
3270                 p = xmalloc(strlen(s) + 2);
3271                 strcpy(p, s);
3272                 strcat(p, "\n");
3273                 setup_string_in_str(&input, p);
3274                 rcode = parse_stream_outer(&input, flag);
3275                 free(p);
3276                 return rcode;
3277         } else {
3278 #endif
3279         setup_string_in_str(&input, s);
3280         return parse_stream_outer(&input, flag);
3281 #ifdef __U_BOOT__
3282         }
3283 #endif
3284 }
3285
3286 #ifndef __U_BOOT__
3287 static int parse_file_outer(FILE *f)
3288 #else
3289 int parse_file_outer(void)
3290 #endif
3291 {
3292         int rcode;
3293         struct in_str input;
3294 #ifndef __U_BOOT__
3295         setup_file_in_str(&input, f);
3296 #else
3297         setup_file_in_str(&input);
3298 #endif
3299         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3300         return rcode;
3301 }
3302
3303 #ifdef __U_BOOT__
3304 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3305 static void u_boot_hush_reloc(void)
3306 {
3307         unsigned long addr;
3308         struct reserved_combo *r;
3309
3310         for (r=reserved_list; r<reserved_list+NRES; r++) {
3311                 addr = (ulong) (r->literal) + gd->reloc_off;
3312                 r->literal = (char *)addr;
3313         }
3314 }
3315 #endif
3316
3317 int u_boot_hush_start(void)
3318 {
3319         if (top_vars == NULL) {
3320                 top_vars = malloc(sizeof(struct variables));
3321                 top_vars->name = "HUSH_VERSION";
3322                 top_vars->value = "0.01";
3323                 top_vars->next = NULL;
3324                 top_vars->flg_export = 0;
3325                 top_vars->flg_read_only = 1;
3326 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3327                 u_boot_hush_reloc();
3328 #endif
3329         }
3330         return 0;
3331 }
3332
3333 static void *xmalloc(size_t size)
3334 {
3335         void *p = NULL;
3336
3337         if (!(p = malloc(size))) {
3338             printf("ERROR : memory not allocated\n");
3339             for(;;);
3340         }
3341         return p;
3342 }
3343
3344 static void *xrealloc(void *ptr, size_t size)
3345 {
3346         void *p = NULL;
3347
3348         if (!(p = realloc(ptr, size))) {
3349             printf("ERROR : memory not allocated\n");
3350             for(;;);
3351         }
3352         return p;
3353 }
3354 #endif /* __U_BOOT__ */
3355
3356 #ifndef __U_BOOT__
3357 /* Make sure we have a controlling tty.  If we get started under a job
3358  * aware app (like bash for example), make sure we are now in charge so
3359  * we don't fight over who gets the foreground */
3360 static void setup_job_control(void)
3361 {
3362         static pid_t shell_pgrp;
3363         /* Loop until we are in the foreground.  */
3364         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3365                 kill (- shell_pgrp, SIGTTIN);
3366
3367         /* Ignore interactive and job-control signals.  */
3368         signal(SIGINT, SIG_IGN);
3369         signal(SIGQUIT, SIG_IGN);
3370         signal(SIGTERM, SIG_IGN);
3371         signal(SIGTSTP, SIG_IGN);
3372         signal(SIGTTIN, SIG_IGN);
3373         signal(SIGTTOU, SIG_IGN);
3374         signal(SIGCHLD, SIG_IGN);
3375
3376         /* Put ourselves in our own process group.  */
3377         setsid();
3378         shell_pgrp = getpid ();
3379         setpgid (shell_pgrp, shell_pgrp);
3380
3381         /* Grab control of the terminal.  */
3382         tcsetpgrp(shell_terminal, shell_pgrp);
3383 }
3384
3385 int hush_main(int argc, char * const *argv)
3386 {
3387         int opt;
3388         FILE *input;
3389         char **e = environ;
3390
3391         /* XXX what should these be while sourcing /etc/profile? */
3392         global_argc = argc;
3393         global_argv = argv;
3394
3395         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3396          * hush_main(), therefore we cannot rely on the BSS to zero out this
3397          * stuff.  Reset these to 0 every time. */
3398         ifs = NULL;
3399         /* map[] is taken care of with call to update_ifs_map() */
3400         fake_mode = 0;
3401         interactive = 0;
3402         close_me_head = NULL;
3403         last_bg_pid = 0;
3404         job_list = NULL;
3405         last_jobid = 0;
3406
3407         /* Initialize some more globals to non-zero values */
3408         set_cwd();
3409 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3410         cmdedit_set_initial_prompt();
3411 #else
3412         PS1 = NULL;
3413 #endif
3414         PS2 = "> ";
3415
3416         /* initialize our shell local variables with the values
3417          * currently living in the environment */
3418         if (e) {
3419                 for (; *e; e++)
3420                         set_local_var(*e, 2);   /* without call putenv() */
3421         }
3422
3423         last_return_code=EXIT_SUCCESS;
3424
3425
3426         if (argv[0] && argv[0][0] == '-') {
3427                 debug_printf("\nsourcing /etc/profile\n");
3428                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3429                         mark_open(fileno(input));
3430                         parse_file_outer(input);
3431                         mark_closed(fileno(input));
3432                         fclose(input);
3433                 }
3434         }
3435         input=stdin;
3436
3437         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3438                 switch (opt) {
3439                         case 'c':
3440                                 {
3441                                         global_argv = argv+optind;
3442                                         global_argc = argc-optind;
3443                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3444                                         goto final_return;
3445                                 }
3446                                 break;
3447                         case 'i':
3448                                 interactive++;
3449                                 break;
3450                         case 'f':
3451                                 fake_mode++;
3452                                 break;
3453                         default:
3454 #ifndef BB_VER
3455                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3456                                                 "   or: sh -c command [args]...\n\n");
3457                                 exit(EXIT_FAILURE);
3458 #else
3459                                 show_usage();
3460 #endif
3461                 }
3462         }
3463         /* A shell is interactive if the `-i' flag was given, or if all of
3464          * the following conditions are met:
3465          *        no -c command
3466          *    no arguments remaining or the -s flag given
3467          *    standard input is a terminal
3468          *    standard output is a terminal
3469          *    Refer to Posix.2, the description of the `sh' utility. */
3470         if (argv[optind]==NULL && input==stdin &&
3471                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3472                 interactive++;
3473         }
3474
3475         debug_printf("\ninteractive=%d\n", interactive);
3476         if (interactive) {
3477                 /* Looks like they want an interactive shell */
3478 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3479                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3480                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3481 #endif
3482                 setup_job_control();
3483         }
3484
3485         if (argv[optind]==NULL) {
3486                 opt=parse_file_outer(stdin);
3487                 goto final_return;
3488         }
3489
3490         debug_printf("\nrunning script '%s'\n", argv[optind]);
3491         global_argv = argv+optind;
3492         global_argc = argc-optind;
3493         input = xfopen(argv[optind], "r");
3494         opt = parse_file_outer(input);
3495
3496 #ifdef CONFIG_FEATURE_CLEAN_UP
3497         fclose(input);
3498         if (cwd && cwd != unknown)
3499                 free((char*)cwd);
3500         {
3501                 struct variables *cur, *tmp;
3502                 for(cur = top_vars; cur; cur = tmp) {
3503                         tmp = cur->next;
3504                         if (!cur->flg_read_only) {
3505                                 free(cur->name);
3506                                 free(cur->value);
3507                                 free(cur);
3508                         }
3509                 }
3510         }
3511 #endif
3512
3513 final_return:
3514         return(opt?opt:last_return_code);
3515 }
3516 #endif
3517
3518 static char *insert_var_value(char *inp)
3519 {
3520         return insert_var_value_sub(inp, 0);
3521 }
3522
3523 static char *insert_var_value_sub(char *inp, int tag_subst)
3524 {
3525         int res_str_len = 0;
3526         int len;
3527         int done = 0;
3528         char *p, *p1, *res_str = NULL;
3529
3530         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3531                 /* check the beginning of the string for normal characters */
3532                 if (p != inp) {
3533                         /* copy any characters to the result string */
3534                         len = p - inp;
3535                         res_str = xrealloc(res_str, (res_str_len + len));
3536                         strncpy((res_str + res_str_len), inp, len);
3537                         res_str_len += len;
3538                 }
3539                 inp = ++p;
3540                 /* find the ending marker */
3541                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3542                 *p = '\0';
3543                 /* look up the value to substitute */
3544                 if ((p1 = lookup_param(inp))) {
3545                         if (tag_subst)
3546                                 len = res_str_len + strlen(p1) + 2;
3547                         else
3548                                 len = res_str_len + strlen(p1);
3549                         res_str = xrealloc(res_str, (1 + len));
3550                         if (tag_subst) {
3551                                 /*
3552                                  * copy the variable value to the result
3553                                  * string
3554                                  */
3555                                 strcpy((res_str + res_str_len + 1), p1);
3556
3557                                 /*
3558                                  * mark the replaced text to be accepted as
3559                                  * is
3560                                  */
3561                                 res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3562                                 res_str[res_str_len + 1 + strlen(p1)] =
3563                                         SUBSTED_VAR_SYMBOL;
3564                         } else
3565                                 /*
3566                                  * copy the variable value to the result
3567                                  * string
3568                                  */
3569                                 strcpy((res_str + res_str_len), p1);
3570
3571                         res_str_len = len;
3572                 }
3573                 *p = SPECIAL_VAR_SYMBOL;
3574                 inp = ++p;
3575                 done = 1;
3576         }
3577         if (done) {
3578                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3579                 strcpy((res_str + res_str_len), inp);
3580                 while ((p = strchr(res_str, '\n'))) {
3581                         *p = ' ';
3582                 }
3583         }
3584         return (res_str == NULL) ? inp : res_str;
3585 }
3586
3587 static char **make_list_in(char **inp, char *name)
3588 {
3589         int len, i;
3590         int name_len = strlen(name);
3591         int n = 0;
3592         char **list;
3593         char *p1, *p2, *p3;
3594
3595         /* create list of variable values */
3596         list = xmalloc(sizeof(*list));
3597         for (i = 0; inp[i]; i++) {
3598                 p3 = insert_var_value(inp[i]);
3599                 p1 = p3;
3600                 while (*p1) {
3601                         if (*p1 == ' ') {
3602                                 p1++;
3603                                 continue;
3604                         }
3605                         if ((p2 = strchr(p1, ' '))) {
3606                                 len = p2 - p1;
3607                         } else {
3608                                 len = strlen(p1);
3609                                 p2 = p1 + len;
3610                         }
3611                         /* we use n + 2 in realloc for list,because we add
3612                          * new element and then we will add NULL element */
3613                         list = xrealloc(list, sizeof(*list) * (n + 2));
3614                         list[n] = xmalloc(2 + name_len + len);
3615                         strcpy(list[n], name);
3616                         strcat(list[n], "=");
3617                         strncat(list[n], p1, len);
3618                         list[n++][name_len + len + 1] = '\0';
3619                         p1 = p2;
3620                 }
3621                 if (p3 != inp[i]) free(p3);
3622         }
3623         list[n] = NULL;
3624         return list;
3625 }
3626
3627 /*
3628  * Make new string for parser
3629  * inp     - array of argument strings to flatten
3630  * nonnull - indicates argument was quoted when originally parsed
3631  */
3632 static char *make_string(char **inp, int *nonnull)
3633 {
3634         char *p;
3635         char *str = NULL;
3636         int n;
3637         int len = 2;
3638         char *noeval_str;
3639         int noeval = 0;
3640
3641         noeval_str = get_local_var("HUSH_NO_EVAL");
3642         if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3643                 noeval = 1;
3644         for (n = 0; inp[n]; n++) {
3645                 p = insert_var_value_sub(inp[n], noeval);
3646                 str = xrealloc(str, (len + strlen(p) + (2 * nonnull[n])));
3647                 if (n) {
3648                         strcat(str, " ");
3649                 } else {
3650                         *str = '\0';
3651                 }
3652                 if (nonnull[n])
3653                         strcat(str, "'");
3654                 strcat(str, p);
3655                 if (nonnull[n])
3656                         strcat(str, "'");
3657                 len = strlen(str) + 3;
3658                 if (p != inp[n]) free(p);
3659         }
3660         len = strlen(str);
3661         *(str + len) = '\n';
3662         *(str + len + 1) = '\0';
3663         return str;
3664 }
3665
3666 #ifdef __U_BOOT__
3667 static int do_showvar(cmd_tbl_t *cmdtp, int flag, int argc,
3668                       char * const argv[])
3669 {
3670         int i, k;
3671         int rcode = 0;
3672         struct variables *cur;
3673
3674         if (argc == 1) {                /* Print all env variables      */
3675                 for (cur = top_vars; cur; cur = cur->next) {
3676                         printf ("%s=%s\n", cur->name, cur->value);
3677                         if (ctrlc ()) {
3678                                 puts ("\n ** Abort\n");
3679                                 return 1;
3680                         }
3681                 }
3682                 return 0;
3683         }
3684         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3685                 char *name = argv[i];
3686
3687                 k = -1;
3688                 for (cur = top_vars; cur; cur = cur->next) {
3689                         if(strcmp (cur->name, name) == 0) {
3690                                 k = 0;
3691                                 printf ("%s=%s\n", cur->name, cur->value);
3692                         }
3693                         if (ctrlc ()) {
3694                                 puts ("\n ** Abort\n");
3695                                 return 1;
3696                         }
3697                 }
3698                 if (k < 0) {
3699                         printf ("## Error: \"%s\" not defined\n", name);
3700                         rcode ++;
3701                 }
3702         }
3703         return rcode;
3704 }
3705
3706 U_BOOT_CMD(
3707         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3708         "print local hushshell variables",
3709         "\n    - print values of all hushshell variables\n"
3710         "showvar name ...\n"
3711         "    - print value of hushshell variable 'name'"
3712 );
3713
3714 #endif
3715 /****************************************************************************/