common/hush.c

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