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  * This program is free software; you can redistribute it and/or modify
  75  * it under the terms of the GNU General Public License as published by
  76  * the Free Software Foundation; either version 2 of the License, or
  77  * (at your option) any later version.
  78  *
  79  * This program is distributed in the hope that it will be useful,
  80  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  81  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  82  * General Public License for more details.
  83  *
  84  * You should have received a copy of the GNU General Public License
  85  * along with this program; if not, write to the Free Software
  86  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  87  */
  88 #define __U_BOOT__
  89 #ifdef __U_BOOT__
  90 #include <malloc.h>         /* malloc, free, realloc*/
  91 #include <linux/ctype.h>    /* isalpha, isdigit */
  92 #include <common.h>        /* readline */
  93 #include <hush.h>
  94 #include <command.h>        /* find_cmd */
  95 #ifndef CONFIG_SYS_PROMPT_HUSH_PS2
  96 #define CONFIG_SYS_PROMPT_HUSH_PS2      "> "
  97 #endif
  98 #endif
  99 #ifndef __U_BOOT__
 100 #include <ctype.h>     /* isalpha, isdigit */
 101 #include <unistd.h>    /* getpid */
 102 #include <stdlib.h>    /* getenv, atoi */
 103 #include <string.h>    /* strchr */
 104 #include <stdio.h>     /* popen etc. */
 105 #include <glob.h>      /* glob, of course */
 106 #include <stdarg.h>    /* va_list */
 107 #include <errno.h>
 108 #include <fcntl.h>
 109 #include <getopt.h>    /* should be pretty obvious */
 110
 111 #include <sys/stat.h>  /* ulimit */
 112 #include <sys/types.h>
 113 #include <sys/wait.h>
 114 #include <signal.h>
 115
 116 /* #include <dmalloc.h> */
 117
 118 #if 1
 119 #include "busybox.h"
 120 #include "cmdedit.h"
 121 #else
 122 #define applet_name "hush"
 123 #include "standalone.h"
 124 #define hush_main main
 125 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 126 #define BB_BANNER
 127 #endif
 128 #endif
 129 #define SPECIAL_VAR_SYMBOL 03
 130 #define SUBSTED_VAR_SYMBOL 04
 131 #ifndef __U_BOOT__
 132 #define FLAG_EXIT_FROM_LOOP 1
 133 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 134 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 135
 136 #endif
 137
 138 #ifdef __U_BOOT__
 139 DECLARE_GLOBAL_DATA_PTR;
 140
 141 #define EXIT_SUCCESS 0
 142 #define EOF -1
 143 #define syntax() syntax_err()
 144 #define xstrdup strdup
 145 #define error_msg printf
 146 #else
 147 typedef enum {
 148         REDIRECT_INPUT     = 1,
 149         REDIRECT_OVERWRITE = 2,
 150         REDIRECT_APPEND    = 3,
 151         REDIRECT_HEREIS    = 4,
 152         REDIRECT_IO        = 5
 153 } redir_type;
 154
 155 /* The descrip member of this structure is only used to make debugging
 156  * output pretty */
 157 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 158         { 0,                         0, "()" },
 159         { O_RDONLY,                  0, "<"  },
 160         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 161         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 162         { O_RDONLY,                 -1, "<<" },
 163         { O_RDWR,                    1, "<>" }
 164 };
 165 #endif
 166
 167 typedef enum {
 168         PIPE_SEQ = 1,
 169         PIPE_AND = 2,
 170         PIPE_OR  = 3,
 171         PIPE_BG  = 4,
 172 } pipe_style;
 173
 174 /* might eventually control execution */
 175 typedef enum {
 176         RES_NONE  = 0,
 177         RES_IF    = 1,
 178         RES_THEN  = 2,
 179         RES_ELIF  = 3,
 180         RES_ELSE  = 4,
 181         RES_FI    = 5,
 182         RES_FOR   = 6,
 183         RES_WHILE = 7,
 184         RES_UNTIL = 8,
 185         RES_DO    = 9,
 186         RES_DONE  = 10,
 187         RES_XXXX  = 11,
 188         RES_IN    = 12,
 189         RES_SNTX  = 13
 190 } reserved_style;
 191 #define FLAG_END   (1<<RES_NONE)
 192 #define FLAG_IF    (1<<RES_IF)
 193 #define FLAG_THEN  (1<<RES_THEN)
 194 #define FLAG_ELIF  (1<<RES_ELIF)
 195 #define FLAG_ELSE  (1<<RES_ELSE)
 196 #define FLAG_FI    (1<<RES_FI)
 197 #define FLAG_FOR   (1<<RES_FOR)
 198 #define FLAG_WHILE (1<<RES_WHILE)
 199 #define FLAG_UNTIL (1<<RES_UNTIL)
 200 #define FLAG_DO    (1<<RES_DO)
 201 #define FLAG_DONE  (1<<RES_DONE)
 202 #define FLAG_IN    (1<<RES_IN)
 203 #define FLAG_START (1<<RES_XXXX)
 204
 205 /* This holds pointers to the various results of parsing */
 206 struct p_context {
 207         struct child_prog *child;
 208         struct pipe *list_head;
 209         struct pipe *pipe;
 210 #ifndef __U_BOOT__
 211         struct redir_struct *pending_redirect;
 212 #endif
 213         reserved_style w;
 214         int old_flag;                           /* for figuring out valid reserved words */
 215         struct p_context *stack;
 216         int type;                       /* define type of parser : ";$" common or special symbol */
 217         /* How about quoting status? */
 218 };
 219
 220 #ifndef __U_BOOT__
 221 struct redir_struct {
 222         redir_type type;                        /* type of redirection */
 223         int fd;                                         /* file descriptor being redirected */
 224         int dup;                                        /* -1, or file descriptor being duplicated */
 225         struct redir_struct *next;      /* pointer to the next redirect in the list */
 226         glob_t word;                            /* *word.gl_pathv is the filename */
 227 };
 228 #endif
 229
 230 struct child_prog {
 231 #ifndef __U_BOOT__
 232         pid_t pid;                                      /* 0 if exited */
 233 #endif
 234         char **argv;                            /* program name and arguments */
 235 #ifdef __U_BOOT__
 236         int    argc;                            /* number of program arguments */
 237 #endif
 238         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 239 #ifndef __U_BOOT__
 240         int subshell;                           /* flag, non-zero if group must be forked */
 241         struct redir_struct *redirects; /* I/O redirections */
 242         glob_t glob_result;                     /* result of parameter globbing */
 243         int is_stopped;                         /* is the program currently running? */
 244         struct pipe *family;            /* pointer back to the child's parent pipe */
 245 #endif
 246         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 247         int type;
 248 };
 249
 250 struct pipe {
 251 #ifndef __U_BOOT__
 252         int jobid;                                      /* job number */
 253 #endif
 254         int num_progs;                          /* total number of programs in job */
 255 #ifndef __U_BOOT__
 256         int running_progs;                      /* number of programs running */
 257         char *text;                                     /* name of job */
 258         char *cmdbuf;                           /* buffer various argv's point into */
 259         pid_t pgrp;                                     /* process group ID for the job */
 260 #endif
 261         struct child_prog *progs;       /* array of commands in pipe */
 262         struct pipe *next;                      /* to track background commands */
 263 #ifndef __U_BOOT__
 264         int stopped_progs;                      /* number of programs alive, but stopped */
 265         int job_context;                        /* bitmask defining current context */
 266 #endif
 267         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 268         reserved_style r_mode;          /* supports if, for, while, until */
 269 };
 270
 271 #ifndef __U_BOOT__
 272 struct close_me {
 273         int fd;
 274         struct close_me *next;
 275 };
 276 #endif
 277
 278 struct variables {
 279         char *name;
 280         char *value;
 281         int flg_export;
 282         int flg_read_only;
 283         struct variables *next;
 284 };
 285
 286 /* globals, connect us to the outside world
 287  * the first three support $?, $#, and $1 */
 288 #ifndef __U_BOOT__
 289 char **global_argv;
 290 unsigned int global_argc;
 291 #endif
 292 static unsigned int last_return_code;
 293 #ifndef __U_BOOT__
 294 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 295 #endif
 296
 297 /* "globals" within this file */
 298 static uchar *ifs;
 299 static char map[256];
 300 #ifndef __U_BOOT__
 301 static int fake_mode;
 302 static int interactive;
 303 static struct close_me *close_me_head;
 304 static const char *cwd;
 305 static struct pipe *job_list;
 306 static unsigned int last_bg_pid;
 307 static unsigned int last_jobid;
 308 static unsigned int shell_terminal;
 309 static char *PS1;
 310 static char *PS2;
 311 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 312 struct variables *top_vars = &shell_ver;
 313 #else
 314 static int flag_repeat = 0;
 315 static int do_repeat = 0;
 316 static struct variables *top_vars = NULL ;
 317 #endif /*__U_BOOT__ */
 318
 319 #define B_CHUNK (100)
 320 #define B_NOSPAC 1
 321
 322 typedef struct {
 323         char *data;
 324         int length;
 325         int maxlen;
 326         int quote;
 327         int nonnull;
 328 } o_string;
 329 #define NULL_O_STRING {NULL,0,0,0,0}
 330 /* used for initialization:
 331         o_string foo = NULL_O_STRING; */
 332
 333 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 334  * available?  Where is it documented? */
 335 struct in_str {
 336         const char *p;
 337 #ifndef __U_BOOT__
 338         char peek_buf[2];
 339 #endif
 340         int __promptme;
 341         int promptmode;
 342 #ifndef __U_BOOT__
 343         FILE *file;
 344 #endif
 345         int (*get) (struct in_str *);
 346         int (*peek) (struct in_str *);
 347 };
 348 #define b_getch(input) ((input)->get(input))
 349 #define b_peek(input) ((input)->peek(input))
 350
 351 #ifndef __U_BOOT__
 352 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 353
 354 struct built_in_command {
 355         char *cmd;                                      /* name */
 356         char *descr;                            /* description */
 357         int (*function) (struct child_prog *);  /* function ptr */
 358 };
 359 #endif
 360
 361 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 362 #if 0
 363 #define DEBUG_SHELL
 364 #endif
 365
 366 /* This should be in utility.c */
 367 #ifdef DEBUG_SHELL
 368 #ifndef __U_BOOT__
 369 static void debug_printf(const char *format, ...)
 370 {
 371         va_list args;
 372         va_start(args, format);
 373         vfprintf(stderr, format, args);
 374         va_end(args);
 375 }
 376 #else
 377 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 378 #endif
 379 #else
 380 static inline void debug_printf(const char *format, ...) { }
 381 #endif
 382 #define final_printf debug_printf
 383
 384 #ifdef __U_BOOT__
 385 static void syntax_err(void) {
 386          printf("syntax error\n");
 387 }
 388 #else
 389 static void __syntax(char *file, int line) {
 390         error_msg("syntax error %s:%d", file, line);
 391 }
 392 #define syntax() __syntax(__FILE__, __LINE__)
 393 #endif
 394
 395 #ifdef __U_BOOT__
 396 static void *xmalloc(size_t size);
 397 static void *xrealloc(void *ptr, size_t size);
 398 #else
 399 /* Index of subroutines: */
 400 /*   function prototypes for builtins */
 401 static int builtin_cd(struct child_prog *child);
 402 static int builtin_env(struct child_prog *child);
 403 static int builtin_eval(struct child_prog *child);
 404 static int builtin_exec(struct child_prog *child);
 405 static int builtin_exit(struct child_prog *child);
 406 static int builtin_export(struct child_prog *child);
 407 static int builtin_fg_bg(struct child_prog *child);
 408 static int builtin_help(struct child_prog *child);
 409 static int builtin_jobs(struct child_prog *child);
 410 static int builtin_pwd(struct child_prog *child);
 411 static int builtin_read(struct child_prog *child);
 412 static int builtin_set(struct child_prog *child);
 413 static int builtin_shift(struct child_prog *child);
 414 static int builtin_source(struct child_prog *child);
 415 static int builtin_umask(struct child_prog *child);
 416 static int builtin_unset(struct child_prog *child);
 417 static int builtin_not_written(struct child_prog *child);
 418 #endif
 419 /*   o_string manipulation: */
 420 static int b_check_space(o_string *o, int len);
 421 static int b_addchr(o_string *o, int ch);
 422 static void b_reset(o_string *o);
 423 static int b_addqchr(o_string *o, int ch, int quote);
 424 #ifndef __U_BOOT__
 425 static int b_adduint(o_string *o, unsigned int i);
 426 #endif
 427 /*  in_str manipulations: */
 428 static int static_get(struct in_str *i);
 429 static int static_peek(struct in_str *i);
 430 static int file_get(struct in_str *i);
 431 static int file_peek(struct in_str *i);
 432 #ifndef __U_BOOT__
 433 static void setup_file_in_str(struct in_str *i, FILE *f);
 434 #else
 435 static void setup_file_in_str(struct in_str *i);
 436 #endif
 437 static void setup_string_in_str(struct in_str *i, const char *s);
 438 #ifndef __U_BOOT__
 439 /*  close_me manipulations: */
 440 static void mark_open(int fd);
 441 static void mark_closed(int fd);
 442 static void close_all(void);
 443 #endif
 444 /*  "run" the final data structures: */
 445 static char *indenter(int i);
 446 static int free_pipe_list(struct pipe *head, int indent);
 447 static int free_pipe(struct pipe *pi, int indent);
 448 /*  really run the final data structures: */
 449 #ifndef __U_BOOT__
 450 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 451 #endif
 452 static int run_list_real(struct pipe *pi);
 453 #ifndef __U_BOOT__
 454 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 455 #endif
 456 static int run_pipe_real(struct pipe *pi);
 457 /*   extended glob support: */
 458 #ifndef __U_BOOT__
 459 static int globhack(const char *src, int flags, glob_t *pglob);
 460 static int glob_needed(const char *s);
 461 static int xglob(o_string *dest, int flags, glob_t *pglob);
 462 #endif
 463 /*   variable assignment: */
 464 static int is_assignment(const char *s);
 465 /*   data structure manipulation: */
 466 #ifndef __U_BOOT__
 467 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 468 #endif
 469 static void initialize_context(struct p_context *ctx);
 470 static int done_word(o_string *dest, struct p_context *ctx);
 471 static int done_command(struct p_context *ctx);
 472 static int done_pipe(struct p_context *ctx, pipe_style type);
 473 /*   primary string parsing: */
 474 #ifndef __U_BOOT__
 475 static int redirect_dup_num(struct in_str *input);
 476 static int redirect_opt_num(o_string *o);
 477 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 478 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 479 #endif
 480 static char *lookup_param(char *src);
 481 static char *make_string(char **inp);
 482 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 483 #ifndef __U_BOOT__
 484 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 485 #endif
 486 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 487 /*   setup: */
 488 static int parse_stream_outer(struct in_str *inp, int flag);
 489 #ifndef __U_BOOT__
 490 static int parse_string_outer(const char *s, int flag);
 491 static int parse_file_outer(FILE *f);
 492 #endif
 493 #ifndef __U_BOOT__
 494 /*   job management: */
 495 static int checkjobs(struct pipe* fg_pipe);
 496 static void insert_bg_job(struct pipe *pi);
 497 static void remove_bg_job(struct pipe *pi);
 498 #endif
 499 /*     local variable support */
 500 static char **make_list_in(char **inp, char *name);
 501 static char *insert_var_value(char *inp);
 502 static char *insert_var_value_sub(char *inp, int tag_subst);
 503
 504 #ifndef __U_BOOT__
 505 /* Table of built-in functions.  They can be forked or not, depending on
 506  * context: within pipes, they fork.  As simple commands, they do not.
 507  * When used in non-forking context, they can change global variables
 508  * in the parent shell process.  If forked, of course they can not.
 509  * For example, 'unset foo | whatever' will parse and run, but foo will
 510  * still be set at the end. */
 511 static struct built_in_command bltins[] = {
 512         {"bg", "Resume a job in the background", builtin_fg_bg},
 513         {"break", "Exit for, while or until loop", builtin_not_written},
 514         {"cd", "Change working directory", builtin_cd},
 515         {"continue", "Continue for, while or until loop", builtin_not_written},
 516         {"env", "Print all environment variables", builtin_env},
 517         {"eval", "Construct and run shell command", builtin_eval},
 518         {"exec", "Exec command, replacing this shell with the exec'd process",
 519                 builtin_exec},
 520         {"exit", "Exit from shell()", builtin_exit},
 521         {"export", "Set environment variable", builtin_export},
 522         {"fg", "Bring job into the foreground", builtin_fg_bg},
 523         {"jobs", "Lists the active jobs", builtin_jobs},
 524         {"pwd", "Print current directory", builtin_pwd},
 525         {"read", "Input environment variable", builtin_read},
 526         {"return", "Return from a function", builtin_not_written},
 527         {"set", "Set/unset shell local variables", builtin_set},
 528         {"shift", "Shift positional parameters", builtin_shift},
 529         {"trap", "Trap signals", builtin_not_written},
 530         {"ulimit","Controls resource limits", builtin_not_written},
 531         {"umask","Sets file creation mask", builtin_umask},
 532         {"unset", "Unset environment variable", builtin_unset},
 533         {".", "Source-in and run commands in a file", builtin_source},
 534         {"help", "List shell built-in commands", builtin_help},
 535         {NULL, NULL, NULL}
 536 };
 537
 538 static const char *set_cwd(void)
 539 {
 540         if(cwd==unknown)
 541                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 542         cwd = xgetcwd((char *)cwd);
 543         if (!cwd)
 544                 cwd = unknown;
 545         return cwd;
 546 }
 547
 548 /* built-in 'eval' handler */
 549 static int builtin_eval(struct child_prog *child)
 550 {
 551         char *str = NULL;
 552         int rcode = EXIT_SUCCESS;
 553
 554         if (child->argv[1]) {
 555                 str = make_string(child->argv + 1);
 556                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 557                                         FLAG_PARSE_SEMICOLON);
 558                 free(str);
 559                 rcode = last_return_code;
 560         }
 561         return rcode;
 562 }
 563
 564 /* built-in 'cd <path>' handler */
 565 static int builtin_cd(struct child_prog *child)
 566 {
 567         char *newdir;
 568         if (child->argv[1] == NULL)
 569                 newdir = getenv("HOME");
 570         else
 571                 newdir = child->argv[1];
 572         if (chdir(newdir)) {
 573                 printf("cd: %s: %s\n", newdir, strerror(errno));
 574                 return EXIT_FAILURE;
 575         }
 576         set_cwd();
 577         return EXIT_SUCCESS;
 578 }
 579
 580 /* built-in 'env' handler */
 581 static int builtin_env(struct child_prog *dummy)
 582 {
 583         char **e = environ;
 584         if (e == NULL) return EXIT_FAILURE;
 585         for (; *e; e++) {
 586                 puts(*e);
 587         }
 588         return EXIT_SUCCESS;
 589 }
 590
 591 /* built-in 'exec' handler */
 592 static int builtin_exec(struct child_prog *child)
 593 {
 594         if (child->argv[1] == NULL)
 595                 return EXIT_SUCCESS;   /* Really? */
 596         child->argv++;
 597         pseudo_exec(child);
 598         /* never returns */
 599 }
 600
 601 /* built-in 'exit' handler */
 602 static int builtin_exit(struct child_prog *child)
 603 {
 604         if (child->argv[1] == NULL)
 605                 exit(last_return_code);
 606         exit (atoi(child->argv[1]));
 607 }
 608
 609 /* built-in 'export VAR=value' handler */
 610 static int builtin_export(struct child_prog *child)
 611 {
 612         int res = 0;
 613         char *name = child->argv[1];
 614
 615         if (name == NULL) {
 616                 return (builtin_env(child));
 617         }
 618
 619         name = strdup(name);
 620
 621         if(name) {
 622                 char *value = strchr(name, '=');
 623
 624                 if (!value) {
 625                         char *tmp;
 626                         /* They are exporting something without an =VALUE */
 627
 628                         value = get_local_var(name);
 629                         if (value) {
 630                                 size_t ln = strlen(name);
 631
 632                                 tmp = realloc(name, ln+strlen(value)+2);
 633                                 if(tmp==NULL)
 634                                         res = -1;
 635                                 else {
 636                                         sprintf(tmp+ln, "=%s", value);
 637                                         name = tmp;
 638                                 }
 639                         } else {
 640                                 /* bash does not return an error when trying to export
 641                                  * an undefined variable.  Do likewise. */
 642                                 res = 1;
 643                         }
 644                 }
 645         }
 646         if (res<0)
 647                 perror_msg("export");
 648         else if(res==0)
 649                 res = set_local_var(name, 1);
 650         else
 651                 res = 0;
 652         free(name);
 653         return res;
 654 }
 655
 656 /* built-in 'fg' and 'bg' handler */
 657 static int builtin_fg_bg(struct child_prog *child)
 658 {
 659         int i, jobnum;
 660         struct pipe *pi=NULL;
 661
 662         if (!interactive)
 663                 return EXIT_FAILURE;
 664         /* If they gave us no args, assume they want the last backgrounded task */
 665         if (!child->argv[1]) {
 666                 for (pi = job_list; pi; pi = pi->next) {
 667                         if (pi->jobid == last_jobid) {
 668                                 break;
 669                         }
 670                 }
 671                 if (!pi) {
 672                         error_msg("%s: no current job", child->argv[0]);
 673                         return EXIT_FAILURE;
 674                 }
 675         } else {
 676                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 677                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 678                         return EXIT_FAILURE;
 679                 }
 680                 for (pi = job_list; pi; pi = pi->next) {
 681                         if (pi->jobid == jobnum) {
 682                                 break;
 683                         }
 684                 }
 685                 if (!pi) {
 686                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 687                         return EXIT_FAILURE;
 688                 }
 689         }
 690
 691         if (*child->argv[0] == 'f') {
 692                 /* Put the job into the foreground.  */
 693                 tcsetpgrp(shell_terminal, pi->pgrp);
 694         }
 695
 696         /* Restart the processes in the job */
 697         for (i = 0; i < pi->num_progs; i++)
 698                 pi->progs[i].is_stopped = 0;
 699
 700         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 701                 if (i == ESRCH) {
 702                         remove_bg_job(pi);
 703                 } else {
 704                         perror_msg("kill (SIGCONT)");
 705                 }
 706         }
 707
 708         pi->stopped_progs = 0;
 709         return EXIT_SUCCESS;
 710 }
 711
 712 /* built-in 'help' handler */
 713 static int builtin_help(struct child_prog *dummy)
 714 {
 715         struct built_in_command *x;
 716
 717         printf("\nBuilt-in commands:\n");
 718         printf("-------------------\n");
 719         for (x = bltins; x->cmd; x++) {
 720                 if (x->descr==NULL)
 721                         continue;
 722                 printf("%s\t%s\n", x->cmd, x->descr);
 723         }
 724         printf("\n\n");
 725         return EXIT_SUCCESS;
 726 }
 727
 728 /* built-in 'jobs' handler */
 729 static int builtin_jobs(struct child_prog *child)
 730 {
 731         struct pipe *job;
 732         char *status_string;
 733
 734         for (job = job_list; job; job = job->next) {
 735                 if (job->running_progs == job->stopped_progs)
 736                         status_string = "Stopped";
 737                 else
 738                         status_string = "Running";
 739
 740                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 741         }
 742         return EXIT_SUCCESS;
 743 }
 744
 745
 746 /* built-in 'pwd' handler */
 747 static int builtin_pwd(struct child_prog *dummy)
 748 {
 749         puts(set_cwd());
 750         return EXIT_SUCCESS;
 751 }
 752
 753 /* built-in 'read VAR' handler */
 754 static int builtin_read(struct child_prog *child)
 755 {
 756         int res;
 757
 758         if (child->argv[1]) {
 759                 char string[BUFSIZ];
 760                 char *var = 0;
 761
 762                 string[0] = 0;  /* In case stdin has only EOF */
 763                 /* read string */
 764                 fgets(string, sizeof(string), stdin);
 765                 chomp(string);
 766                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 767                 if(var) {
 768                         sprintf(var, "%s=%s", child->argv[1], string);
 769                         res = set_local_var(var, 0);
 770                 } else
 771                         res = -1;
 772                 if (res)
 773                         fprintf(stderr, "read: %m\n");
 774                 free(var);      /* So not move up to avoid breaking errno */
 775                 return res;
 776         } else {
 777                 do res=getchar(); while(res!='\n' && res!=EOF);
 778                 return 0;
 779         }
 780 }
 781
 782 /* built-in 'set VAR=value' handler */
 783 static int builtin_set(struct child_prog *child)
 784 {
 785         char *temp = child->argv[1];
 786         struct variables *e;
 787
 788         if (temp == NULL)
 789                 for(e = top_vars; e; e=e->next)
 790                         printf("%s=%s\n", e->name, e->value);
 791         else
 792                 set_local_var(temp, 0);
 793
 794                 return EXIT_SUCCESS;
 795 }
 796
 797
 798 /* Built-in 'shift' handler */
 799 static int builtin_shift(struct child_prog *child)
 800 {
 801         int n=1;
 802         if (child->argv[1]) {
 803                 n=atoi(child->argv[1]);
 804         }
 805         if (n>=0 && n<global_argc) {
 806                 /* XXX This probably breaks $0 */
 807                 global_argc -= n;
 808                 global_argv += n;
 809                 return EXIT_SUCCESS;
 810         } else {
 811                 return EXIT_FAILURE;
 812         }
 813 }
 814
 815 /* Built-in '.' handler (read-in and execute commands from file) */
 816 static int builtin_source(struct child_prog *child)
 817 {
 818         FILE *input;
 819         int status;
 820
 821         if (child->argv[1] == NULL)
 822                 return EXIT_FAILURE;
 823
 824         /* XXX search through $PATH is missing */
 825         input = fopen(child->argv[1], "r");
 826         if (!input) {
 827                 error_msg("Couldn't open file '%s'", child->argv[1]);
 828                 return EXIT_FAILURE;
 829         }
 830
 831         /* Now run the file */
 832         /* XXX argv and argc are broken; need to save old global_argv
 833          * (pointer only is OK!) on this stack frame,
 834          * set global_argv=child->argv+1, recurse, and restore. */
 835         mark_open(fileno(input));
 836         status = parse_file_outer(input);
 837         mark_closed(fileno(input));
 838         fclose(input);
 839         return (status);
 840 }
 841
 842 static int builtin_umask(struct child_prog *child)
 843 {
 844         mode_t new_umask;
 845         const char *arg = child->argv[1];
 846         char *end;
 847         if (arg) {
 848                 new_umask=strtoul(arg, &end, 8);
 849                 if (*end!='\0' || end == arg) {
 850                         return EXIT_FAILURE;
 851                 }
 852         } else {
 853                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 854         }
 855         umask(new_umask);
 856         return EXIT_SUCCESS;
 857 }
 858
 859 /* built-in 'unset VAR' handler */
 860 static int builtin_unset(struct child_prog *child)
 861 {
 862         /* bash returned already true */
 863         unset_local_var(child->argv[1]);
 864         return EXIT_SUCCESS;
 865 }
 866
 867 static int builtin_not_written(struct child_prog *child)
 868 {
 869         printf("builtin_%s not written\n",child->argv[0]);
 870         return EXIT_FAILURE;
 871 }
 872 #endif
 873
 874 static int b_check_space(o_string *o, int len)
 875 {
 876         /* It would be easy to drop a more restrictive policy
 877          * in here, such as setting a maximum string length */
 878         if (o->length + len > o->maxlen) {
 879                 char *old_data = o->data;
 880                 /* assert (data == NULL || o->maxlen != 0); */
 881                 o->maxlen += max(2*len, B_CHUNK);
 882                 o->data = realloc(o->data, 1 + o->maxlen);
 883                 if (o->data == NULL) {
 884                         free(old_data);
 885                 }
 886         }
 887         return o->data == NULL;
 888 }
 889
 890 static int b_addchr(o_string *o, int ch)
 891 {
 892         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 893         if (b_check_space(o, 1)) return B_NOSPAC;
 894         o->data[o->length] = ch;
 895         o->length++;
 896         o->data[o->length] = '\0';
 897         return 0;
 898 }
 899
 900 static void b_reset(o_string *o)
 901 {
 902         o->length = 0;
 903         o->nonnull = 0;
 904         if (o->data != NULL) *o->data = '\0';
 905 }
 906
 907 static void b_free(o_string *o)
 908 {
 909         b_reset(o);
 910         free(o->data);
 911         o->data = NULL;
 912         o->maxlen = 0;
 913 }
 914
 915 /* My analysis of quoting semantics tells me that state information
 916  * is associated with a destination, not a source.
 917  */
 918 static int b_addqchr(o_string *o, int ch, int quote)
 919 {
 920         if (quote && strchr("*?[\\",ch)) {
 921                 int rc;
 922                 rc = b_addchr(o, '\\');
 923                 if (rc) return rc;
 924         }
 925         return b_addchr(o, ch);
 926 }
 927
 928 #ifndef __U_BOOT__
 929 static int b_adduint(o_string *o, unsigned int i)
 930 {
 931         int r;
 932         char *p = simple_itoa(i);
 933         /* no escape checking necessary */
 934         do r=b_addchr(o, *p++); while (r==0 && *p);
 935         return r;
 936 }
 937 #endif
 938
 939 static int static_get(struct in_str *i)
 940 {
 941         int ch = *i->p++;
 942         if (ch=='\0') return EOF;
 943         return ch;
 944 }
 945
 946 static int static_peek(struct in_str *i)
 947 {
 948         return *i->p;
 949 }
 950
 951 #ifndef __U_BOOT__
 952 static inline void cmdedit_set_initial_prompt(void)
 953 {
 954 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 955         PS1 = NULL;
 956 #else
 957         PS1 = getenv("PS1");
 958         if(PS1==0)
 959                 PS1 = "\\w \\$ ";
 960 #endif
 961 }
 962
 963 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 964 {
 965         debug_printf("setup_prompt_string %d ",promptmode);
 966 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 967         /* Set up the prompt */
 968         if (promptmode == 1) {
 969                 free(PS1);
 970                 PS1=xmalloc(strlen(cwd)+4);
 971                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 972                 *prompt_str = PS1;
 973         } else {
 974                 *prompt_str = PS2;
 975         }
 976 #else
 977         *prompt_str = (promptmode==1)? PS1 : PS2;
 978 #endif
 979         debug_printf("result %s\n",*prompt_str);
 980 }
 981 #endif
 982
 983 static void get_user_input(struct in_str *i)
 984 {
 985 #ifndef __U_BOOT__
 986         char *prompt_str;
 987         static char the_command[BUFSIZ];
 988
 989         setup_prompt_string(i->promptmode, &prompt_str);
 990 #ifdef CONFIG_FEATURE_COMMAND_EDITING
 991         /*
 992          ** enable command line editing only while a command line
 993          ** is actually being read; otherwise, we'll end up bequeathing
 994          ** atexit() handlers and other unwanted stuff to our
 995          ** child processes (rob@sysgo.de)
 996          */
 997         cmdedit_read_input(prompt_str, the_command);
 998 #else
 999         fputs(prompt_str, stdout);
1000         fflush(stdout);
1001         the_command[0]=fgetc(i->file);
1002         the_command[1]='\0';
1003 #endif
1004         fflush(stdout);
1005         i->p = the_command;
1006 #else
1007         int n;
1008         static char the_command[CONFIG_SYS_CBSIZE];
1009
1010 #ifdef CONFIG_BOOT_RETRY_TIME
1011 #  ifndef CONFIG_RESET_TO_RETRY
1012 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1013 #  endif
1014         reset_cmd_timeout();
1015 #endif
1016         i->__promptme = 1;
1017         if (i->promptmode == 1) {
1018                 n = readline(CONFIG_SYS_PROMPT);
1019         } else {
1020                 n = readline(CONFIG_SYS_PROMPT_HUSH_PS2);
1021         }
1022 #ifdef CONFIG_BOOT_RETRY_TIME
1023         if (n == -2) {
1024           puts("\nTimeout waiting for command\n");
1025 #  ifdef CONFIG_RESET_TO_RETRY
1026           do_reset(NULL, 0, 0, NULL);
1027 #  else
1028 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1029 #  endif
1030         }
1031 #endif
1032         if (n == -1 ) {
1033                 flag_repeat = 0;
1034                 i->__promptme = 0;
1035         }
1036         n = strlen(console_buffer);
1037         console_buffer[n] = '\n';
1038         console_buffer[n+1]= '\0';
1039         if (had_ctrlc()) flag_repeat = 0;
1040         clear_ctrlc();
1041         do_repeat = 0;
1042         if (i->promptmode == 1) {
1043                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1044                         strcpy(the_command,console_buffer);
1045                 }
1046                 else {
1047                         if (console_buffer[0] != '\n') {
1048                                 strcpy(the_command,console_buffer);
1049                                 flag_repeat = 1;
1050                         }
1051                         else {
1052                                 do_repeat = 1;
1053                         }
1054                 }
1055                 i->p = the_command;
1056         }
1057         else {
1058                 if (console_buffer[0] != '\n') {
1059                         if (strlen(the_command) + strlen(console_buffer)
1060                             < CONFIG_SYS_CBSIZE) {
1061                                 n = strlen(the_command);
1062                                 the_command[n-1] = ' ';
1063                                 strcpy(&the_command[n],console_buffer);
1064                         }
1065                         else {
1066                                 the_command[0] = '\n';
1067                                 the_command[1] = '\0';
1068                                 flag_repeat = 0;
1069                         }
1070                 }
1071                 if (i->__promptme == 0) {
1072                         the_command[0] = '\n';
1073                         the_command[1] = '\0';
1074                 }
1075                 i->p = console_buffer;
1076         }
1077 #endif
1078 }
1079
1080 /* This is the magic location that prints prompts
1081  * and gets data back from the user */
1082 static int file_get(struct in_str *i)
1083 {
1084         int ch;
1085
1086         ch = 0;
1087         /* If there is data waiting, eat it up */
1088         if (i->p && *i->p) {
1089                 ch = *i->p++;
1090         } else {
1091                 /* need to double check i->file because we might be doing something
1092                  * more complicated by now, like sourcing or substituting. */
1093 #ifndef __U_BOOT__
1094                 if (i->__promptme && interactive && i->file == stdin) {
1095                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1096 #else
1097                         while(! i->p  || strlen(i->p)==0 ) {
1098 #endif
1099                                 get_user_input(i);
1100                         }
1101                         i->promptmode=2;
1102 #ifndef __U_BOOT__
1103                         i->__promptme = 0;
1104 #endif
1105                         if (i->p && *i->p) {
1106                                 ch = *i->p++;
1107                         }
1108 #ifndef __U_BOOT__
1109                 } else {
1110                         ch = fgetc(i->file);
1111                 }
1112
1113 #endif
1114                 debug_printf("b_getch: got a %d\n", ch);
1115         }
1116 #ifndef __U_BOOT__
1117         if (ch == '\n') i->__promptme=1;
1118 #endif
1119         return ch;
1120 }
1121
1122 /* All the callers guarantee this routine will never be
1123  * used right after a newline, so prompting is not needed.
1124  */
1125 static int file_peek(struct in_str *i)
1126 {
1127 #ifndef __U_BOOT__
1128         if (i->p && *i->p) {
1129 #endif
1130                 return *i->p;
1131 #ifndef __U_BOOT__
1132         } else {
1133                 i->peek_buf[0] = fgetc(i->file);
1134                 i->peek_buf[1] = '\0';
1135                 i->p = i->peek_buf;
1136                 debug_printf("b_peek: got a %d\n", *i->p);
1137                 return *i->p;
1138         }
1139 #endif
1140 }
1141
1142 #ifndef __U_BOOT__
1143 static void setup_file_in_str(struct in_str *i, FILE *f)
1144 #else
1145 static void setup_file_in_str(struct in_str *i)
1146 #endif
1147 {
1148         i->peek = file_peek;
1149         i->get = file_get;
1150         i->__promptme=1;
1151         i->promptmode=1;
1152 #ifndef __U_BOOT__
1153         i->file = f;
1154 #endif
1155         i->p = NULL;
1156 }
1157
1158 static void setup_string_in_str(struct in_str *i, const char *s)
1159 {
1160         i->peek = static_peek;
1161         i->get = static_get;
1162         i->__promptme=1;
1163         i->promptmode=1;
1164         i->p = s;
1165 }
1166
1167 #ifndef __U_BOOT__
1168 static void mark_open(int fd)
1169 {
1170         struct close_me *new = xmalloc(sizeof(struct close_me));
1171         new->fd = fd;
1172         new->next = close_me_head;
1173         close_me_head = new;
1174 }
1175
1176 static void mark_closed(int fd)
1177 {
1178         struct close_me *tmp;
1179         if (close_me_head == NULL || close_me_head->fd != fd)
1180                 error_msg_and_die("corrupt close_me");
1181         tmp = close_me_head;
1182         close_me_head = close_me_head->next;
1183         free(tmp);
1184 }
1185
1186 static void close_all(void)
1187 {
1188         struct close_me *c;
1189         for (c=close_me_head; c; c=c->next) {
1190                 close(c->fd);
1191         }
1192         close_me_head = NULL;
1193 }
1194
1195 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1196  * and stderr if they are redirected. */
1197 static int setup_redirects(struct child_prog *prog, int squirrel[])
1198 {
1199         int openfd, mode;
1200         struct redir_struct *redir;
1201
1202         for (redir=prog->redirects; redir; redir=redir->next) {
1203                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1204                         /* something went wrong in the parse.  Pretend it didn't happen */
1205                         continue;
1206                 }
1207                 if (redir->dup == -1) {
1208                         mode=redir_table[redir->type].mode;
1209                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1210                         if (openfd < 0) {
1211                         /* this could get lost if stderr has been redirected, but
1212                            bash and ash both lose it as well (though zsh doesn't!) */
1213                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1214                                 return 1;
1215                         }
1216                 } else {
1217                         openfd = redir->dup;
1218                 }
1219
1220                 if (openfd != redir->fd) {
1221                         if (squirrel && redir->fd < 3) {
1222                                 squirrel[redir->fd] = dup(redir->fd);
1223                         }
1224                         if (openfd == -3) {
1225                                 close(openfd);
1226                         } else {
1227                                 dup2(openfd, redir->fd);
1228                                 if (redir->dup == -1)
1229                                         close (openfd);
1230                         }
1231                 }
1232         }
1233         return 0;
1234 }
1235
1236 static void restore_redirects(int squirrel[])
1237 {
1238         int i, fd;
1239         for (i=0; i<3; i++) {
1240                 fd = squirrel[i];
1241                 if (fd != -1) {
1242                         /* No error checking.  I sure wouldn't know what
1243                          * to do with an error if I found one! */
1244                         dup2(fd, i);
1245                         close(fd);
1246                 }
1247         }
1248 }
1249
1250 /* never returns */
1251 /* XXX no exit() here.  If you don't exec, use _exit instead.
1252  * The at_exit handlers apparently confuse the calling process,
1253  * in particular stdin handling.  Not sure why? */
1254 static void pseudo_exec(struct child_prog *child)
1255 {
1256         int i, rcode;
1257         char *p;
1258         struct built_in_command *x;
1259         if (child->argv) {
1260                 for (i=0; is_assignment(child->argv[i]); i++) {
1261                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1262                         p = insert_var_value(child->argv[i]);
1263                         putenv(strdup(p));
1264                         if (p != child->argv[i]) free(p);
1265                 }
1266                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1267                                         to exit, and therefore don't need to keep data
1268                                         structures consistent for free() use. */
1269                 /* If a variable is assigned in a forest, and nobody listens,
1270                  * was it ever really set?
1271                  */
1272                 if (child->argv[0] == NULL) {
1273                         _exit(EXIT_SUCCESS);
1274                 }
1275
1276                 /*
1277                  * Check if the command matches any of the builtins.
1278                  * Depending on context, this might be redundant.  But it's
1279                  * easier to waste a few CPU cycles than it is to figure out
1280                  * if this is one of those cases.
1281                  */
1282                 for (x = bltins; x->cmd; x++) {
1283                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1284                                 debug_printf("builtin exec %s\n", child->argv[0]);
1285                                 rcode = x->function(child);
1286                                 fflush(stdout);
1287                                 _exit(rcode);
1288                         }
1289                 }
1290
1291                 /* Check if the command matches any busybox internal commands
1292                  * ("applets") here.
1293                  * FIXME: This feature is not 100% safe, since
1294                  * BusyBox is not fully reentrant, so we have no guarantee the things
1295                  * from the .bss are still zeroed, or that things from .data are still
1296                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1297                  * really dislike relying on /proc for things.  We could exec ourself
1298                  * from global_argv[0], but if we are in a chroot, we may not be able
1299                  * to find ourself... */
1300 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1301                 {
1302                         int argc_l;
1303                         char** argv_l=child->argv;
1304                         char *name = child->argv[0];
1305
1306 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1307                         /* Following discussions from November 2000 on the busybox mailing
1308                          * list, the default configuration, (without
1309                          * get_last_path_component()) lets the user force use of an
1310                          * external command by specifying the full (with slashes) filename.
1311                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1312                          * _aways_ override external commands, so if you want to run
1313                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1314                          * filesystem and is _not_ busybox.  Some systems may want this,
1315                          * most do not.  */
1316                         name = get_last_path_component(name);
1317 #endif
1318                         /* Count argc for use in a second... */
1319                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1320                         optind = 1;
1321                         debug_printf("running applet %s\n", name);
1322                         run_applet_by_name(name, argc_l, child->argv);
1323                 }
1324 #endif
1325                 debug_printf("exec of %s\n",child->argv[0]);
1326                 execvp(child->argv[0],child->argv);
1327                 perror_msg("couldn't exec: %s",child->argv[0]);
1328                 _exit(1);
1329         } else if (child->group) {
1330                 debug_printf("runtime nesting to group\n");
1331                 interactive=0;    /* crucial!!!! */
1332                 rcode = run_list_real(child->group);
1333                 /* OK to leak memory by not calling free_pipe_list,
1334                  * since this process is about to exit */
1335                 _exit(rcode);
1336         } else {
1337                 /* Can happen.  See what bash does with ">foo" by itself. */
1338                 debug_printf("trying to pseudo_exec null command\n");
1339                 _exit(EXIT_SUCCESS);
1340         }
1341 }
1342
1343 static void insert_bg_job(struct pipe *pi)
1344 {
1345         struct pipe *thejob;
1346
1347         /* Linear search for the ID of the job to use */
1348         pi->jobid = 1;
1349         for (thejob = job_list; thejob; thejob = thejob->next)
1350                 if (thejob->jobid >= pi->jobid)
1351                         pi->jobid = thejob->jobid + 1;
1352
1353         /* add thejob to the list of running jobs */
1354         if (!job_list) {
1355                 thejob = job_list = xmalloc(sizeof(*thejob));
1356         } else {
1357                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1358                 thejob->next = xmalloc(sizeof(*thejob));
1359                 thejob = thejob->next;
1360         }
1361
1362         /* physically copy the struct job */
1363         memcpy(thejob, pi, sizeof(struct pipe));
1364         thejob->next = NULL;
1365         thejob->running_progs = thejob->num_progs;
1366         thejob->stopped_progs = 0;
1367         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1368
1369         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1370         {
1371                 char *bar=thejob->text;
1372                 char **foo=pi->progs[0].argv;
1373                 while(foo && *foo) {
1374                         bar += sprintf(bar, "%s ", *foo++);
1375                 }
1376         }
1377
1378         /* we don't wait for background thejobs to return -- append it
1379            to the list of backgrounded thejobs and leave it alone */
1380         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1381         last_bg_pid = thejob->progs[0].pid;
1382         last_jobid = thejob->jobid;
1383 }
1384
1385 /* remove a backgrounded job */
1386 static void remove_bg_job(struct pipe *pi)
1387 {
1388         struct pipe *prev_pipe;
1389
1390         if (pi == job_list) {
1391                 job_list = pi->next;
1392         } else {
1393                 prev_pipe = job_list;
1394                 while (prev_pipe->next != pi)
1395                         prev_pipe = prev_pipe->next;
1396                 prev_pipe->next = pi->next;
1397         }
1398         if (job_list)
1399                 last_jobid = job_list->jobid;
1400         else
1401                 last_jobid = 0;
1402
1403         pi->stopped_progs = 0;
1404         free_pipe(pi, 0);
1405         free(pi);
1406 }
1407
1408 /* Checks to see if any processes have exited -- if they
1409    have, figure out why and see if a job has completed */
1410 static int checkjobs(struct pipe* fg_pipe)
1411 {
1412         int attributes;
1413         int status;
1414         int prognum = 0;
1415         struct pipe *pi;
1416         pid_t childpid;
1417
1418         attributes = WUNTRACED;
1419         if (fg_pipe==NULL) {
1420                 attributes |= WNOHANG;
1421         }
1422
1423         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1424                 if (fg_pipe) {
1425                         int i, rcode = 0;
1426                         for (i=0; i < fg_pipe->num_progs; i++) {
1427                                 if (fg_pipe->progs[i].pid == childpid) {
1428                                         if (i==fg_pipe->num_progs-1)
1429                                                 rcode=WEXITSTATUS(status);
1430                                         (fg_pipe->num_progs)--;
1431                                         return(rcode);
1432                                 }
1433                         }
1434                 }
1435
1436                 for (pi = job_list; pi; pi = pi->next) {
1437                         prognum = 0;
1438                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1439                                 prognum++;
1440                         }
1441                         if (prognum < pi->num_progs)
1442                                 break;
1443                 }
1444
1445                 if(pi==NULL) {
1446                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1447                         continue;
1448                 }
1449
1450                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1451                         /* child exited */
1452                         pi->running_progs--;
1453                         pi->progs[prognum].pid = 0;
1454
1455                         if (!pi->running_progs) {
1456                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1457                                 remove_bg_job(pi);
1458                         }
1459                 } else {
1460                         /* child stopped */
1461                         pi->stopped_progs++;
1462                         pi->progs[prognum].is_stopped = 1;
1463
1464 #if 0
1465                         /* Printing this stuff is a pain, since it tends to
1466                          * overwrite the prompt an inconveinient moments.  So
1467                          * don't do that.  */
1468                         if (pi->stopped_progs == pi->num_progs) {
1469                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1470                         }
1471 #endif
1472                 }
1473         }
1474
1475         if (childpid == -1 && errno != ECHILD)
1476                 perror_msg("waitpid");
1477
1478         /* move the shell to the foreground */
1479         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1480         /*      perror_msg("tcsetpgrp-2"); */
1481         return -1;
1482 }
1483
1484 /* Figure out our controlling tty, checking in order stderr,
1485  * stdin, and stdout.  If check_pgrp is set, also check that
1486  * we belong to the foreground process group associated with
1487  * that tty.  The value of shell_terminal is needed in order to call
1488  * tcsetpgrp(shell_terminal, ...); */
1489 void controlling_tty(int check_pgrp)
1490 {
1491         pid_t curpgrp;
1492
1493         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1494                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1495                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1496                 goto shell_terminal_error;
1497
1498         if (check_pgrp && curpgrp != getpgid(0))
1499                 goto shell_terminal_error;
1500
1501         return;
1502
1503 shell_terminal_error:
1504                 shell_terminal = -1;
1505                 return;
1506 }
1507 #endif
1508
1509 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1510  * to finish.  See checkjobs().
1511  *
1512  * return code is normally -1, when the caller has to wait for children
1513  * to finish to determine the exit status of the pipe.  If the pipe
1514  * is a simple builtin command, however, the action is done by the
1515  * time run_pipe_real returns, and the exit code is provided as the
1516  * return value.
1517  *
1518  * The input of the pipe is always stdin, the output is always
1519  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1520  * because it tries to avoid running the command substitution in
1521  * subshell, when that is in fact necessary.  The subshell process
1522  * now has its stdout directed to the input of the appropriate pipe,
1523  * so this routine is noticeably simpler.
1524  */
1525 static int run_pipe_real(struct pipe *pi)
1526 {
1527         int i;
1528 #ifndef __U_BOOT__
1529         int nextin, nextout;
1530         int pipefds[2];                         /* pipefds[0] is for reading */
1531         struct child_prog *child;
1532         struct built_in_command *x;
1533         char *p;
1534 # if __GNUC__
1535         /* Avoid longjmp clobbering */
1536         (void) &i;
1537         (void) &nextin;
1538         (void) &nextout;
1539         (void) &child;
1540 # endif
1541 #else
1542         int nextin;
1543         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1544         struct child_prog *child;
1545         char *p;
1546 # if __GNUC__
1547         /* Avoid longjmp clobbering */
1548         (void) &i;
1549         (void) &nextin;
1550         (void) &child;
1551 # endif
1552 #endif  /* __U_BOOT__ */
1553
1554         nextin = 0;
1555 #ifndef __U_BOOT__
1556         pi->pgrp = -1;
1557 #endif
1558
1559         /* Check if this is a simple builtin (not part of a pipe).
1560          * Builtins within pipes have to fork anyway, and are handled in
1561          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1562          */
1563         if (pi->num_progs == 1) child = & (pi->progs[0]);
1564 #ifndef __U_BOOT__
1565         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1566                 int squirrel[] = {-1, -1, -1};
1567                 int rcode;
1568                 debug_printf("non-subshell grouping\n");
1569                 setup_redirects(child, squirrel);
1570                 /* XXX could we merge code with following builtin case,
1571                  * by creating a pseudo builtin that calls run_list_real? */
1572                 rcode = run_list_real(child->group);
1573                 restore_redirects(squirrel);
1574 #else
1575                 if (pi->num_progs == 1 && child->group) {
1576                 int rcode;
1577                 debug_printf("non-subshell grouping\n");
1578                 rcode = run_list_real(child->group);
1579 #endif
1580                 return rcode;
1581         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1582                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1583                 if (i!=0 && child->argv[i]==NULL) {
1584                         /* assignments, but no command: set the local environment */
1585                         for (i=0; child->argv[i]!=NULL; i++) {
1586
1587                                 /* Ok, this case is tricky.  We have to decide if this is a
1588                                  * local variable, or an already exported variable.  If it is
1589                                  * already exported, we have to export the new value.  If it is
1590                                  * not exported, we need only set this as a local variable.
1591                                  * This junk is all to decide whether or not to export this
1592                                  * variable. */
1593                                 int export_me=0;
1594                                 char *name, *value;
1595                                 name = xstrdup(child->argv[i]);
1596                                 debug_printf("Local environment set: %s\n", name);
1597                                 value = strchr(name, '=');
1598                                 if (value)
1599                                         *value=0;
1600 #ifndef __U_BOOT__
1601                                 if ( get_local_var(name)) {
1602                                         export_me=1;
1603                                 }
1604 #endif
1605                                 free(name);
1606                                 p = insert_var_value(child->argv[i]);
1607                                 set_local_var(p, export_me);
1608                                 if (p != child->argv[i]) free(p);
1609                         }
1610                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1611                 }
1612                 for (i = 0; is_assignment(child->argv[i]); i++) {
1613                         p = insert_var_value(child->argv[i]);
1614 #ifndef __U_BOOT__
1615                         putenv(strdup(p));
1616 #else
1617                         set_local_var(p, 0);
1618 #endif
1619                         if (p != child->argv[i]) {
1620                                 child->sp--;
1621                                 free(p);
1622                         }
1623                 }
1624                 if (child->sp) {
1625                         char * str = NULL;
1626
1627                         str = make_string((child->argv + i));
1628                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1629                         free(str);
1630                         return last_return_code;
1631                 }
1632 #ifndef __U_BOOT__
1633                 for (x = bltins; x->cmd; x++) {
1634                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1635                                 int squirrel[] = {-1, -1, -1};
1636                                 int rcode;
1637                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1638                                         debug_printf("magic exec\n");
1639                                         setup_redirects(child,NULL);
1640                                         return EXIT_SUCCESS;
1641                                 }
1642                                 debug_printf("builtin inline %s\n", child->argv[0]);
1643                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1644                                  * This is perfect for work that comes after exec().
1645                                  * Is it really safe for inline use?  Experimentally,
1646                                  * things seem to work with glibc. */
1647                                 setup_redirects(child, squirrel);
1648
1649                                 child->argv += i;  /* XXX horrible hack */
1650                                 rcode = x->function(child);
1651                                 /* XXX restore hack so free() can work right */
1652                                 child->argv -= i;
1653                                 restore_redirects(squirrel);
1654                         }
1655                         return rcode;
1656                 }
1657 #else
1658                 /* check ";", because ,example , argv consist from
1659                  * "help;flinfo" must not execute
1660                  */
1661                 if (strchr(child->argv[i], ';')) {
1662                         printf("Unknown command '%s' - try 'help' or use "
1663                                         "'run' command\n", child->argv[i]);
1664                         return -1;
1665                 }
1666                 /* Process the command */
1667                 return cmd_process(flag, child->argc, child->argv,
1668                                    &flag_repeat, NULL);
1669 #endif
1670         }
1671 #ifndef __U_BOOT__
1672
1673         for (i = 0; i < pi->num_progs; i++) {
1674                 child = & (pi->progs[i]);
1675
1676                 /* pipes are inserted between pairs of commands */
1677                 if ((i + 1) < pi->num_progs) {
1678                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1679                         nextout = pipefds[1];
1680                 } else {
1681                         nextout=1;
1682                         pipefds[0] = -1;
1683                 }
1684
1685                 /* XXX test for failed fork()? */
1686                 if (!(child->pid = fork())) {
1687                         /* Set the handling for job control signals back to the default.  */
1688                         signal(SIGINT, SIG_DFL);
1689                         signal(SIGQUIT, SIG_DFL);
1690                         signal(SIGTERM, SIG_DFL);
1691                         signal(SIGTSTP, SIG_DFL);
1692                         signal(SIGTTIN, SIG_DFL);
1693                         signal(SIGTTOU, SIG_DFL);
1694                         signal(SIGCHLD, SIG_DFL);
1695
1696                         close_all();
1697
1698                         if (nextin != 0) {
1699                                 dup2(nextin, 0);
1700                                 close(nextin);
1701                         }
1702                         if (nextout != 1) {
1703                                 dup2(nextout, 1);
1704                                 close(nextout);
1705                         }
1706                         if (pipefds[0]!=-1) {
1707                                 close(pipefds[0]);  /* opposite end of our output pipe */
1708                         }
1709
1710                         /* Like bash, explicit redirects override pipes,
1711                          * and the pipe fd is available for dup'ing. */
1712                         setup_redirects(child,NULL);
1713
1714                         if (interactive && pi->followup!=PIPE_BG) {
1715                                 /* If we (the child) win the race, put ourselves in the process
1716                                  * group whose leader is the first process in this pipe. */
1717                                 if (pi->pgrp < 0) {
1718                                         pi->pgrp = getpid();
1719                                 }
1720                                 if (setpgid(0, pi->pgrp) == 0) {
1721                                         tcsetpgrp(2, pi->pgrp);
1722                                 }
1723                         }
1724
1725                         pseudo_exec(child);
1726                 }
1727
1728
1729                 /* put our child in the process group whose leader is the
1730                    first process in this pipe */
1731                 if (pi->pgrp < 0) {
1732                         pi->pgrp = child->pid;
1733                 }
1734                 /* Don't check for errors.  The child may be dead already,
1735                  * in which case setpgid returns error code EACCES. */
1736                 setpgid(child->pid, pi->pgrp);
1737
1738                 if (nextin != 0)
1739                         close(nextin);
1740                 if (nextout != 1)
1741                         close(nextout);
1742
1743                 /* If there isn't another process, nextin is garbage
1744                    but it doesn't matter */
1745                 nextin = pipefds[0];
1746         }
1747 #endif
1748         return -1;
1749 }
1750
1751 static int run_list_real(struct pipe *pi)
1752 {
1753         char *save_name = NULL;
1754         char **list = NULL;
1755         char **save_list = NULL;
1756         struct pipe *rpipe;
1757         int flag_rep = 0;
1758 #ifndef __U_BOOT__
1759         int save_num_progs;
1760 #endif
1761         int rcode=0, flag_skip=1;
1762         int flag_restore = 0;
1763         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1764         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1765         /* check syntax for "for" */
1766         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1767                 if ((rpipe->r_mode == RES_IN ||
1768                     rpipe->r_mode == RES_FOR) &&
1769                     (rpipe->next == NULL)) {
1770                                 syntax();
1771 #ifdef __U_BOOT__
1772                                 flag_repeat = 0;
1773 #endif
1774                                 return 1;
1775                 }
1776                 if ((rpipe->r_mode == RES_IN &&
1777                         (rpipe->next->r_mode == RES_IN &&
1778                         rpipe->next->progs->argv != NULL))||
1779                         (rpipe->r_mode == RES_FOR &&
1780                         rpipe->next->r_mode != RES_IN)) {
1781                                 syntax();
1782 #ifdef __U_BOOT__
1783                                 flag_repeat = 0;
1784 #endif
1785                                 return 1;
1786                 }
1787         }
1788         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1789                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1790                         pi->r_mode == RES_FOR) {
1791 #ifdef __U_BOOT__
1792                                 /* check Ctrl-C */
1793                                 ctrlc();
1794                                 if ((had_ctrlc())) {
1795                                         return 1;
1796                                 }
1797 #endif
1798                                 flag_restore = 0;
1799                                 if (!rpipe) {
1800                                         flag_rep = 0;
1801                                         rpipe = pi;
1802                                 }
1803                 }
1804                 rmode = pi->r_mode;
1805                 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);
1806                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1807                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1808                         continue;
1809                 }
1810                 flag_skip = 1;
1811                 skip_more_in_this_rmode = RES_XXXX;
1812                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1813                 if (rmode == RES_THEN &&  if_code) continue;
1814                 if (rmode == RES_ELSE && !if_code) continue;
1815                 if (rmode == RES_ELIF && !if_code) break;
1816                 if (rmode == RES_FOR && pi->num_progs) {
1817                         if (!list) {
1818                                 /* if no variable values after "in" we skip "for" */
1819                                 if (!pi->next->progs->argv) continue;
1820                                 /* create list of variable values */
1821                                 list = make_list_in(pi->next->progs->argv,
1822                                         pi->progs->argv[0]);
1823                                 save_list = list;
1824                                 save_name = pi->progs->argv[0];
1825                                 pi->progs->argv[0] = NULL;
1826                                 flag_rep = 1;
1827                         }
1828                         if (!(*list)) {
1829                                 free(pi->progs->argv[0]);
1830                                 free(save_list);
1831                                 list = NULL;
1832                                 flag_rep = 0;
1833                                 pi->progs->argv[0] = save_name;
1834 #ifndef __U_BOOT__
1835                                 pi->progs->glob_result.gl_pathv[0] =
1836                                         pi->progs->argv[0];
1837 #endif
1838                                 continue;
1839                         } else {
1840                                 /* insert new value from list for variable */
1841                                 if (pi->progs->argv[0])
1842                                         free(pi->progs->argv[0]);
1843                                 pi->progs->argv[0] = *list++;
1844 #ifndef __U_BOOT__
1845                                 pi->progs->glob_result.gl_pathv[0] =
1846                                         pi->progs->argv[0];
1847 #endif
1848                         }
1849                 }
1850                 if (rmode == RES_IN) continue;
1851                 if (rmode == RES_DO) {
1852                         if (!flag_rep) continue;
1853                 }
1854                 if ((rmode == RES_DONE)) {
1855                         if (flag_rep) {
1856                                 flag_restore = 1;
1857                         } else {
1858                                 rpipe = NULL;
1859                         }
1860                 }
1861                 if (pi->num_progs == 0) continue;
1862 #ifndef __U_BOOT__
1863                 save_num_progs = pi->num_progs; /* save number of programs */
1864 #endif
1865                 rcode = run_pipe_real(pi);
1866                 debug_printf("run_pipe_real returned %d\n",rcode);
1867 #ifndef __U_BOOT__
1868                 if (rcode!=-1) {
1869                         /* We only ran a builtin: rcode was set by the return value
1870                          * of run_pipe_real(), and we don't need to wait for anything. */
1871                 } else if (pi->followup==PIPE_BG) {
1872                         /* XXX check bash's behavior with nontrivial pipes */
1873                         /* XXX compute jobid */
1874                         /* XXX what does bash do with attempts to background builtins? */
1875                         insert_bg_job(pi);
1876                         rcode = EXIT_SUCCESS;
1877                 } else {
1878                         if (interactive) {
1879                                 /* move the new process group into the foreground */
1880                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1881                                         perror_msg("tcsetpgrp-3");
1882                                 rcode = checkjobs(pi);
1883                                 /* move the shell to the foreground */
1884                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1885                                         perror_msg("tcsetpgrp-4");
1886                         } else {
1887                                 rcode = checkjobs(pi);
1888                         }
1889                         debug_printf("checkjobs returned %d\n",rcode);
1890                 }
1891                 last_return_code=rcode;
1892 #else
1893                 if (rcode < -1) {
1894                         last_return_code = -rcode - 2;
1895                         return -2;      /* exit */
1896                 }
1897                 last_return_code=(rcode == 0) ? 0 : 1;
1898 #endif
1899 #ifndef __U_BOOT__
1900                 pi->num_progs = save_num_progs; /* restore number of programs */
1901 #endif
1902                 if ( rmode == RES_IF || rmode == RES_ELIF )
1903                         next_if_code=rcode;  /* can be overwritten a number of times */
1904                 if (rmode == RES_WHILE)
1905                         flag_rep = !last_return_code;
1906                 if (rmode == RES_UNTIL)
1907                         flag_rep = last_return_code;
1908                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1909                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1910                         skip_more_in_this_rmode=rmode;
1911 #ifndef __U_BOOT__
1912                 checkjobs(NULL);
1913 #endif
1914         }
1915         return rcode;
1916 }
1917
1918 /* broken, of course, but OK for testing */
1919 static char *indenter(int i)
1920 {
1921         static char blanks[]="                                    ";
1922         return &blanks[sizeof(blanks)-i-1];
1923 }
1924
1925 /* return code is the exit status of the pipe */
1926 static int free_pipe(struct pipe *pi, int indent)
1927 {
1928         char **p;
1929         struct child_prog *child;
1930 #ifndef __U_BOOT__
1931         struct redir_struct *r, *rnext;
1932 #endif
1933         int a, i, ret_code=0;
1934         char *ind = indenter(indent);
1935
1936 #ifndef __U_BOOT__
1937         if (pi->stopped_progs > 0)
1938                 return ret_code;
1939         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1940 #endif
1941         for (i=0; i<pi->num_progs; i++) {
1942                 child = &pi->progs[i];
1943                 final_printf("%s  command %d:\n",ind,i);
1944                 if (child->argv) {
1945                         for (a=0,p=child->argv; *p; a++,p++) {
1946                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1947                         }
1948 #ifndef __U_BOOT__
1949                         globfree(&child->glob_result);
1950 #else
1951                         for (a = 0; a < child->argc; a++) {
1952                                 free(child->argv[a]);
1953                         }
1954                                         free(child->argv);
1955                         child->argc = 0;
1956 #endif
1957                         child->argv=NULL;
1958                 } else if (child->group) {
1959 #ifndef __U_BOOT__
1960                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1961 #endif
1962                         ret_code = free_pipe_list(child->group,indent+3);
1963                         final_printf("%s   end group\n",ind);
1964                 } else {
1965                         final_printf("%s   (nil)\n",ind);
1966                 }
1967 #ifndef __U_BOOT__
1968                 for (r=child->redirects; r; r=rnext) {
1969                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1970                         if (r->dup == -1) {
1971                                 /* guard against the case >$FOO, where foo is unset or blank */
1972                                 if (r->word.gl_pathv) {
1973                                         final_printf(" %s\n", *r->word.gl_pathv);
1974                                         globfree(&r->word);
1975                                 }
1976                         } else {
1977                                 final_printf("&%d\n", r->dup);
1978                         }
1979                         rnext=r->next;
1980                         free(r);
1981                 }
1982                 child->redirects=NULL;
1983 #endif
1984         }
1985         free(pi->progs);   /* children are an array, they get freed all at once */
1986         pi->progs=NULL;
1987         return ret_code;
1988 }
1989
1990 static int free_pipe_list(struct pipe *head, int indent)
1991 {
1992         int rcode=0;   /* if list has no members */
1993         struct pipe *pi, *next;
1994         char *ind = indenter(indent);
1995         for (pi=head; pi; pi=next) {
1996                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1997                 rcode = free_pipe(pi, indent);
1998                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1999                 next=pi->next;
2000                 pi->next=NULL;
2001                 free(pi);
2002         }
2003         return rcode;
2004 }
2005
2006 /* Select which version we will use */
2007 static int run_list(struct pipe *pi)
2008 {
2009         int rcode=0;
2010 #ifndef __U_BOOT__
2011         if (fake_mode==0) {
2012 #endif
2013                 rcode = run_list_real(pi);
2014 #ifndef __U_BOOT__
2015         }
2016 #endif
2017         /* free_pipe_list has the side effect of clearing memory
2018          * In the long run that function can be merged with run_list_real,
2019          * but doing that now would hobble the debugging effort. */
2020         free_pipe_list(pi,0);
2021         return rcode;
2022 }
2023
2024 /* The API for glob is arguably broken.  This routine pushes a non-matching
2025  * string into the output structure, removing non-backslashed backslashes.
2026  * If someone can prove me wrong, by performing this function within the
2027  * original glob(3) api, feel free to rewrite this routine into oblivion.
2028  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2029  * XXX broken if the last character is '\\', check that before calling.
2030  */
2031 #ifndef __U_BOOT__
2032 static int globhack(const char *src, int flags, glob_t *pglob)
2033 {
2034         int cnt=0, pathc;
2035         const char *s;
2036         char *dest;
2037         for (cnt=1, s=src; s && *s; s++) {
2038                 if (*s == '\\') s++;
2039                 cnt++;
2040         }
2041         dest = malloc(cnt);
2042         if (!dest) return GLOB_NOSPACE;
2043         if (!(flags & GLOB_APPEND)) {
2044                 pglob->gl_pathv=NULL;
2045                 pglob->gl_pathc=0;
2046                 pglob->gl_offs=0;
2047                 pglob->gl_offs=0;
2048         }
2049         pathc = ++pglob->gl_pathc;
2050         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2051         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2052         pglob->gl_pathv[pathc-1]=dest;
2053         pglob->gl_pathv[pathc]=NULL;
2054         for (s=src; s && *s; s++, dest++) {
2055                 if (*s == '\\') s++;
2056                 *dest = *s;
2057         }
2058         *dest='\0';
2059         return 0;
2060 }
2061
2062 /* XXX broken if the last character is '\\', check that before calling */
2063 static int glob_needed(const char *s)
2064 {
2065         for (; *s; s++) {
2066                 if (*s == '\\') s++;
2067                 if (strchr("*[?",*s)) return 1;
2068         }
2069         return 0;
2070 }
2071
2072 #if 0
2073 static void globprint(glob_t *pglob)
2074 {
2075         int i;
2076         debug_printf("glob_t at %p:\n", pglob);
2077         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2078                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2079         for (i=0; i<pglob->gl_pathc; i++)
2080                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2081                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2082 }
2083 #endif
2084
2085 static int xglob(o_string *dest, int flags, glob_t *pglob)
2086 {
2087         int gr;
2088
2089         /* short-circuit for null word */
2090         /* we can code this better when the debug_printf's are gone */
2091         if (dest->length == 0) {
2092                 if (dest->nonnull) {
2093                         /* bash man page calls this an "explicit" null */
2094                         gr = globhack(dest->data, flags, pglob);
2095                         debug_printf("globhack returned %d\n",gr);
2096                 } else {
2097                         return 0;
2098                 }
2099         } else if (glob_needed(dest->data)) {
2100                 gr = glob(dest->data, flags, NULL, pglob);
2101                 debug_printf("glob returned %d\n",gr);
2102                 if (gr == GLOB_NOMATCH) {
2103                         /* quote removal, or more accurately, backslash removal */
2104                         gr = globhack(dest->data, flags, pglob);
2105                         debug_printf("globhack returned %d\n",gr);
2106                 }
2107         } else {
2108                 gr = globhack(dest->data, flags, pglob);
2109                 debug_printf("globhack returned %d\n",gr);
2110         }
2111         if (gr == GLOB_NOSPACE)
2112                 error_msg_and_die("out of memory during glob");
2113         if (gr != 0) { /* GLOB_ABORTED ? */
2114                 error_msg("glob(3) error %d",gr);
2115         }
2116         /* globprint(glob_target); */
2117         return gr;
2118 }
2119 #endif
2120
2121 #ifdef __U_BOOT__
2122 static char *get_dollar_var(char ch);
2123 #endif
2124
2125 /* This is used to get/check local shell variables */
2126 char *get_local_var(const char *s)
2127 {
2128         struct variables *cur;
2129
2130         if (!s)
2131                 return NULL;
2132
2133 #ifdef __U_BOOT__
2134         if (*s == '$')
2135                 return get_dollar_var(s[1]);
2136 #endif
2137
2138         for (cur = top_vars; cur; cur=cur->next)
2139                 if(strcmp(cur->name, s)==0)
2140                         return cur->value;
2141         return NULL;
2142 }
2143
2144 /* This is used to set local shell variables
2145    flg_export==0 if only local (not exporting) variable
2146    flg_export==1 if "new" exporting environ
2147    flg_export>1  if current startup environ (not call putenv()) */
2148 int set_local_var(const char *s, int flg_export)
2149 {
2150         char *name, *value;
2151         int result=0;
2152         struct variables *cur;
2153
2154 #ifdef __U_BOOT__
2155         /* might be possible! */
2156         if (!isalpha(*s))
2157                 return -1;
2158 #endif
2159
2160         name=strdup(s);
2161
2162 #ifdef __U_BOOT__
2163         if (getenv(name) != NULL) {
2164                 printf ("ERROR: "
2165                                 "There is a global environment variable with the same name.\n");
2166                 free(name);
2167                 return -1;
2168         }
2169 #endif
2170         /* Assume when we enter this function that we are already in
2171          * NAME=VALUE format.  So the first order of business is to
2172          * split 's' on the '=' into 'name' and 'value' */
2173         value = strchr(name, '=');
2174         if (value == NULL && ++value == NULL) {
2175                 free(name);
2176                 return -1;
2177         }
2178         *value++ = 0;
2179
2180         for(cur = top_vars; cur; cur = cur->next) {
2181                 if(strcmp(cur->name, name)==0)
2182                         break;
2183         }
2184
2185         if(cur) {
2186                 if(strcmp(cur->value, value)==0) {
2187                         if(flg_export>0 && cur->flg_export==0)
2188                                 cur->flg_export=flg_export;
2189                         else
2190                                 result++;
2191                 } else {
2192                         if(cur->flg_read_only) {
2193                                 error_msg("%s: readonly variable", name);
2194                                 result = -1;
2195                         } else {
2196                                 if(flg_export>0 || cur->flg_export>1)
2197                                         cur->flg_export=1;
2198                                 free(cur->value);
2199
2200                                 cur->value = strdup(value);
2201                         }
2202                 }
2203         } else {
2204                 cur = malloc(sizeof(struct variables));
2205                 if(!cur) {
2206                         result = -1;
2207                 } else {
2208                         cur->name = strdup(name);
2209                         if (cur->name == NULL) {
2210                                 free(cur);
2211                                 result = -1;
2212                         } else {
2213                                 struct variables *bottom = top_vars;
2214                                 cur->value = strdup(value);
2215                                 cur->next = NULL;
2216                                 cur->flg_export = flg_export;
2217                                 cur->flg_read_only = 0;
2218                                 while(bottom->next) bottom=bottom->next;
2219                                 bottom->next = cur;
2220                         }
2221                 }
2222         }
2223
2224 #ifndef __U_BOOT__
2225         if(result==0 && cur->flg_export==1) {
2226                 *(value-1) = '=';
2227                 result = putenv(name);
2228         } else {
2229 #endif
2230                 free(name);
2231 #ifndef __U_BOOT__
2232                 if(result>0)            /* equivalent to previous set */
2233                         result = 0;
2234         }
2235 #endif
2236         return result;
2237 }
2238
2239 void unset_local_var(const char *name)
2240 {
2241         struct variables *cur;
2242
2243         if (name) {
2244                 for (cur = top_vars; cur; cur=cur->next) {
2245                         if(strcmp(cur->name, name)==0)
2246                                 break;
2247                 }
2248                 if (cur != NULL) {
2249                         struct variables *next = top_vars;
2250                         if(cur->flg_read_only) {
2251                                 error_msg("%s: readonly variable", name);
2252                                 return;
2253                         } else {
2254 #ifndef __U_BOOT__
2255                                 if(cur->flg_export)
2256                                         unsetenv(cur->name);
2257 #endif
2258                                 free(cur->name);
2259                                 free(cur->value);
2260                                 while (next->next != cur)
2261                                         next = next->next;
2262                                 next->next = cur->next;
2263                         }
2264                         free(cur);
2265                 }
2266         }
2267 }
2268
2269 static int is_assignment(const char *s)
2270 {
2271         if (s == NULL)
2272                 return 0;
2273
2274         if (!isalpha(*s)) return 0;
2275         ++s;
2276         while(isalnum(*s) || *s=='_') ++s;
2277         return *s=='=';
2278 }
2279
2280 #ifndef __U_BOOT__
2281 /* the src parameter allows us to peek forward to a possible &n syntax
2282  * for file descriptor duplication, e.g., "2>&1".
2283  * Return code is 0 normally, 1 if a syntax error is detected in src.
2284  * Resource errors (in xmalloc) cause the process to exit */
2285 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2286         struct in_str *input)
2287 {
2288         struct child_prog *child=ctx->child;
2289         struct redir_struct *redir = child->redirects;
2290         struct redir_struct *last_redir=NULL;
2291
2292         /* Create a new redir_struct and drop it onto the end of the linked list */
2293         while(redir) {
2294                 last_redir=redir;
2295                 redir=redir->next;
2296         }
2297         redir = xmalloc(sizeof(struct redir_struct));
2298         redir->next=NULL;
2299         redir->word.gl_pathv=NULL;
2300         if (last_redir) {
2301                 last_redir->next=redir;
2302         } else {
2303                 child->redirects=redir;
2304         }
2305
2306         redir->type=style;
2307         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2308
2309         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2310
2311         /* Check for a '2>&1' type redirect */
2312         redir->dup = redirect_dup_num(input);
2313         if (redir->dup == -2) return 1;  /* syntax error */
2314         if (redir->dup != -1) {
2315                 /* Erik had a check here that the file descriptor in question
2316                  * is legit; I postpone that to "run time"
2317                  * A "-" representation of "close me" shows up as a -3 here */
2318                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2319         } else {
2320                 /* We do _not_ try to open the file that src points to,
2321                  * since we need to return and let src be expanded first.
2322                  * Set ctx->pending_redirect, so we know what to do at the
2323                  * end of the next parsed word.
2324                  */
2325                 ctx->pending_redirect = redir;
2326         }
2327         return 0;
2328 }
2329 #endif
2330
2331 static struct pipe *new_pipe(void)
2332 {
2333         struct pipe *pi;
2334         pi = xmalloc(sizeof(struct pipe));
2335         pi->num_progs = 0;
2336         pi->progs = NULL;
2337         pi->next = NULL;
2338         pi->followup = 0;  /* invalid */
2339         pi->r_mode = RES_NONE;
2340         return pi;
2341 }
2342
2343 static void initialize_context(struct p_context *ctx)
2344 {
2345         ctx->pipe=NULL;
2346 #ifndef __U_BOOT__
2347         ctx->pending_redirect=NULL;
2348 #endif
2349         ctx->child=NULL;
2350         ctx->list_head=new_pipe();
2351         ctx->pipe=ctx->list_head;
2352         ctx->w=RES_NONE;
2353         ctx->stack=NULL;
2354 #ifdef __U_BOOT__
2355         ctx->old_flag=0;
2356 #endif
2357         done_command(ctx);   /* creates the memory for working child */
2358 }
2359
2360 /* normal return is 0
2361  * if a reserved word is found, and processed, return 1
2362  * should handle if, then, elif, else, fi, for, while, until, do, done.
2363  * case, function, and select are obnoxious, save those for later.
2364  */
2365 struct reserved_combo {
2366         char *literal;
2367         int code;
2368         long flag;
2369 };
2370 /* Mostly a list of accepted follow-up reserved words.
2371  * FLAG_END means we are done with the sequence, and are ready
2372  * to turn the compound list into a command.
2373  * FLAG_START means the word must start a new compound list.
2374  */
2375 static struct reserved_combo reserved_list[] = {
2376         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2377         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2378         { "elif",  RES_ELIF,  FLAG_THEN },
2379         { "else",  RES_ELSE,  FLAG_FI   },
2380         { "fi",    RES_FI,    FLAG_END  },
2381         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2382         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2383         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2384         { "in",    RES_IN,    FLAG_DO   },
2385         { "do",    RES_DO,    FLAG_DONE },
2386         { "done",  RES_DONE,  FLAG_END  }
2387 };
2388 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2389
2390 static int reserved_word(o_string *dest, struct p_context *ctx)
2391 {
2392         struct reserved_combo *r;
2393         for (r=reserved_list;
2394                 r<reserved_list+NRES; r++) {
2395                 if (strcmp(dest->data, r->literal) == 0) {
2396                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2397                         if (r->flag & FLAG_START) {
2398                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2399                                 debug_printf("push stack\n");
2400                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2401                                         syntax();
2402                                         free(new);
2403                                         ctx->w = RES_SNTX;
2404                                         b_reset(dest);
2405                                         return 1;
2406                                 }
2407                                 *new = *ctx;   /* physical copy */
2408                                 initialize_context(ctx);
2409                                 ctx->stack=new;
2410                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2411                                 syntax();
2412                                 ctx->w = RES_SNTX;
2413                                 b_reset(dest);
2414                                 return 1;
2415                         }
2416                         ctx->w=r->code;
2417                         ctx->old_flag = r->flag;
2418                         if (ctx->old_flag & FLAG_END) {
2419                                 struct p_context *old;
2420                                 debug_printf("pop stack\n");
2421                                 done_pipe(ctx,PIPE_SEQ);
2422                                 old = ctx->stack;
2423                                 old->child->group = ctx->list_head;
2424 #ifndef __U_BOOT__
2425                                 old->child->subshell = 0;
2426 #endif
2427                                 *ctx = *old;   /* physical copy */
2428                                 free(old);
2429                         }
2430                         b_reset (dest);
2431                         return 1;
2432                 }
2433         }
2434         return 0;
2435 }
2436
2437 /* normal return is 0.
2438  * Syntax or xglob errors return 1. */
2439 static int done_word(o_string *dest, struct p_context *ctx)
2440 {
2441         struct child_prog *child=ctx->child;
2442 #ifndef __U_BOOT__
2443         glob_t *glob_target;
2444         int gr, flags = 0;
2445 #else
2446         char *str, *s;
2447         int argc, cnt;
2448 #endif
2449
2450         debug_printf("done_word: %s %p\n", dest->data, child);
2451         if (dest->length == 0 && !dest->nonnull) {
2452                 debug_printf("  true null, ignored\n");
2453                 return 0;
2454         }
2455 #ifndef __U_BOOT__
2456         if (ctx->pending_redirect) {
2457                 glob_target = &ctx->pending_redirect->word;
2458         } else {
2459 #endif
2460                 if (child->group) {
2461                         syntax();
2462                         return 1;  /* syntax error, groups and arglists don't mix */
2463                 }
2464                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2465                         debug_printf("checking %s for reserved-ness\n",dest->data);
2466                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2467                 }
2468 #ifndef __U_BOOT__
2469                 glob_target = &child->glob_result;
2470                 if (child->argv) flags |= GLOB_APPEND;
2471 #else
2472                 for (cnt = 1, s = dest->data; s && *s; s++) {
2473                         if (*s == '\\') s++;
2474                         cnt++;
2475                 }
2476                 str = malloc(cnt);
2477                 if (!str) return 1;
2478                 if ( child->argv == NULL) {
2479                         child->argc=0;
2480                 }
2481                 argc = ++child->argc;
2482                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2483                 if (child->argv == NULL) return 1;
2484                 child->argv[argc-1]=str;
2485                 child->argv[argc]=NULL;
2486                 for (s = dest->data; s && *s; s++,str++) {
2487                         if (*s == '\\') s++;
2488                         *str = *s;
2489                 }
2490                 *str = '\0';
2491 #endif
2492 #ifndef __U_BOOT__
2493         }
2494         gr = xglob(dest, flags, glob_target);
2495         if (gr != 0) return 1;
2496 #endif
2497
2498         b_reset(dest);
2499 #ifndef __U_BOOT__
2500         if (ctx->pending_redirect) {
2501                 ctx->pending_redirect=NULL;
2502                 if (glob_target->gl_pathc != 1) {
2503                         error_msg("ambiguous redirect");
2504                         return 1;
2505                 }
2506         } else {
2507                 child->argv = glob_target->gl_pathv;
2508         }
2509 #endif
2510         if (ctx->w == RES_FOR) {
2511                 done_word(dest,ctx);
2512                 done_pipe(ctx,PIPE_SEQ);
2513         }
2514         return 0;
2515 }
2516
2517 /* The only possible error here is out of memory, in which case
2518  * xmalloc exits. */
2519 static int done_command(struct p_context *ctx)
2520 {
2521         /* The child is really already in the pipe structure, so
2522          * advance the pipe counter and make a new, null child.
2523          * Only real trickiness here is that the uncommitted
2524          * child structure, to which ctx->child points, is not
2525          * counted in pi->num_progs. */
2526         struct pipe *pi=ctx->pipe;
2527         struct child_prog *prog=ctx->child;
2528
2529         if (prog && prog->group == NULL
2530                  && prog->argv == NULL
2531 #ifndef __U_BOOT__
2532                  && prog->redirects == NULL) {
2533 #else
2534                                                                                 ) {
2535 #endif
2536                 debug_printf("done_command: skipping null command\n");
2537                 return 0;
2538         } else if (prog) {
2539                 pi->num_progs++;
2540                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2541         } else {
2542                 debug_printf("done_command: initializing\n");
2543         }
2544         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2545
2546         prog = pi->progs + pi->num_progs;
2547 #ifndef __U_BOOT__
2548         prog->redirects = NULL;
2549 #endif
2550         prog->argv = NULL;
2551 #ifndef __U_BOOT__
2552         prog->is_stopped = 0;
2553 #endif
2554         prog->group = NULL;
2555 #ifndef __U_BOOT__
2556         prog->glob_result.gl_pathv = NULL;
2557         prog->family = pi;
2558 #endif
2559         prog->sp = 0;
2560         ctx->child = prog;
2561         prog->type = ctx->type;
2562
2563         /* but ctx->pipe and ctx->list_head remain unchanged */
2564         return 0;
2565 }
2566
2567 static int done_pipe(struct p_context *ctx, pipe_style type)
2568 {
2569         struct pipe *new_p;
2570         done_command(ctx);  /* implicit closure of previous command */
2571         debug_printf("done_pipe, type %d\n", type);
2572         ctx->pipe->followup = type;
2573         ctx->pipe->r_mode = ctx->w;
2574         new_p=new_pipe();
2575         ctx->pipe->next = new_p;
2576         ctx->pipe = new_p;
2577         ctx->child = NULL;
2578         done_command(ctx);  /* set up new pipe to accept commands */
2579         return 0;
2580 }
2581
2582 #ifndef __U_BOOT__
2583 /* peek ahead in the in_str to find out if we have a "&n" construct,
2584  * as in "2>&1", that represents duplicating a file descriptor.
2585  * returns either -2 (syntax error), -1 (no &), or the number found.
2586  */
2587 static int redirect_dup_num(struct in_str *input)
2588 {
2589         int ch, d=0, ok=0;
2590         ch = b_peek(input);
2591         if (ch != '&') return -1;
2592
2593         b_getch(input);  /* get the & */
2594         ch=b_peek(input);
2595         if (ch == '-') {
2596                 b_getch(input);
2597                 return -3;  /* "-" represents "close me" */
2598         }
2599         while (isdigit(ch)) {
2600                 d = d*10+(ch-'0');
2601                 ok=1;
2602                 b_getch(input);
2603                 ch = b_peek(input);
2604         }
2605         if (ok) return d;
2606
2607         error_msg("ambiguous redirect");
2608         return -2;
2609 }
2610
2611 /* If a redirect is immediately preceded by a number, that number is
2612  * supposed to tell which file descriptor to redirect.  This routine
2613  * looks for such preceding numbers.  In an ideal world this routine
2614  * needs to handle all the following classes of redirects...
2615  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2616  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2617  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2618  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2619  * A -1 output from this program means no valid number was found, so the
2620  * caller should use the appropriate default for this redirection.
2621  */
2622 static int redirect_opt_num(o_string *o)
2623 {
2624         int num;
2625
2626         if (o->length==0) return -1;
2627         for(num=0; num<o->length; num++) {
2628                 if (!isdigit(*(o->data+num))) {
2629                         return -1;
2630                 }
2631         }
2632         /* reuse num (and save an int) */
2633         num=atoi(o->data);
2634         b_reset(o);
2635         return num;
2636 }
2637
2638 FILE *generate_stream_from_list(struct pipe *head)
2639 {
2640         FILE *pf;
2641 #if 1
2642         int pid, channel[2];
2643         if (pipe(channel)<0) perror_msg_and_die("pipe");
2644         pid=fork();
2645         if (pid<0) {
2646                 perror_msg_and_die("fork");
2647         } else if (pid==0) {
2648                 close(channel[0]);
2649                 if (channel[1] != 1) {
2650                         dup2(channel[1],1);
2651                         close(channel[1]);
2652                 }
2653 #if 0
2654 #define SURROGATE "surrogate response"
2655                 write(1,SURROGATE,sizeof(SURROGATE));
2656                 _exit(run_list(head));
2657 #else
2658                 _exit(run_list_real(head));   /* leaks memory */
2659 #endif
2660         }
2661         debug_printf("forked child %d\n",pid);
2662         close(channel[1]);
2663         pf = fdopen(channel[0],"r");
2664         debug_printf("pipe on FILE *%p\n",pf);
2665 #else
2666         free_pipe_list(head,0);
2667         pf=popen("echo surrogate response","r");
2668         debug_printf("started fake pipe on FILE *%p\n",pf);
2669 #endif
2670         return pf;
2671 }
2672
2673 /* this version hacked for testing purposes */
2674 /* return code is exit status of the process that is run. */
2675 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2676 {
2677         int retcode;
2678         o_string result=NULL_O_STRING;
2679         struct p_context inner;
2680         FILE *p;
2681         struct in_str pipe_str;
2682         initialize_context(&inner);
2683
2684         /* recursion to generate command */
2685         retcode = parse_stream(&result, &inner, input, subst_end);
2686         if (retcode != 0) return retcode;  /* syntax error or EOF */
2687         done_word(&result, &inner);
2688         done_pipe(&inner, PIPE_SEQ);
2689         b_free(&result);
2690
2691         p=generate_stream_from_list(inner.list_head);
2692         if (p==NULL) return 1;
2693         mark_open(fileno(p));
2694         setup_file_in_str(&pipe_str, p);
2695
2696         /* now send results of command back into original context */
2697         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2698         /* XXX In case of a syntax error, should we try to kill the child?
2699          * That would be tough to do right, so just read until EOF. */
2700         if (retcode == 1) {
2701                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2702         }
2703
2704         debug_printf("done reading from pipe, pclose()ing\n");
2705         /* This is the step that wait()s for the child.  Should be pretty
2706          * safe, since we just read an EOF from its stdout.  We could try
2707          * to better, by using wait(), and keeping track of background jobs
2708          * at the same time.  That would be a lot of work, and contrary
2709          * to the KISS philosophy of this program. */
2710         mark_closed(fileno(p));
2711         retcode=pclose(p);
2712         free_pipe_list(inner.list_head,0);
2713         debug_printf("pclosed, retcode=%d\n",retcode);
2714         /* XXX this process fails to trim a single trailing newline */
2715         return retcode;
2716 }
2717
2718 static int parse_group(o_string *dest, struct p_context *ctx,
2719         struct in_str *input, int ch)
2720 {
2721         int rcode, endch=0;
2722         struct p_context sub;
2723         struct child_prog *child = ctx->child;
2724         if (child->argv) {
2725                 syntax();
2726                 return 1;  /* syntax error, groups and arglists don't mix */
2727         }
2728         initialize_context(&sub);
2729         switch(ch) {
2730                 case '(': endch=')'; child->subshell=1; break;
2731                 case '{': endch='}'; break;
2732                 default: syntax();   /* really logic error */
2733         }
2734         rcode=parse_stream(dest,&sub,input,endch);
2735         done_word(dest,&sub); /* finish off the final word in the subcontext */
2736         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2737         child->group = sub.list_head;
2738         return rcode;
2739         /* child remains "open", available for possible redirects */
2740 }
2741 #endif
2742
2743 /* basically useful version until someone wants to get fancier,
2744  * see the bash man page under "Parameter Expansion" */
2745 static char *lookup_param(char *src)
2746 {
2747         char *p;
2748         char *sep;
2749         char *default_val = NULL;
2750         int assign = 0;
2751         int expand_empty = 0;
2752
2753         if (!src)
2754                 return NULL;
2755
2756         sep = strchr(src, ':');
2757
2758         if (sep) {
2759                 *sep = '\0';
2760                 if (*(sep + 1) == '-')
2761                         default_val = sep+2;
2762                 if (*(sep + 1) == '=') {
2763                         default_val = sep+2;
2764                         assign = 1;
2765                 }
2766                 if (*(sep + 1) == '+') {
2767                         default_val = sep+2;
2768                         expand_empty = 1;
2769                 }
2770         }
2771
2772         p = getenv(src);
2773         if (!p)
2774                 p = get_local_var(src);
2775
2776         if (!p || strlen(p) == 0) {
2777                 p = default_val;
2778                 if (assign) {
2779                         char *var = malloc(strlen(src)+strlen(default_val)+2);
2780                         if (var) {
2781                                 sprintf(var, "%s=%s", src, default_val);
2782                                 set_local_var(var, 0);
2783                         }
2784                         free(var);
2785                 }
2786         } else if (expand_empty) {
2787                 p += strlen(p);
2788         }
2789
2790         if (sep)
2791                 *sep = ':';
2792
2793         return p;
2794 }
2795
2796 #ifdef __U_BOOT__
2797 static char *get_dollar_var(char ch)
2798 {
2799         static char buf[40];
2800
2801         buf[0] = '\0';
2802         switch (ch) {
2803                 case '?':
2804                         sprintf(buf, "%u", (unsigned int)last_return_code);
2805                         break;
2806                 default:
2807                         return NULL;
2808         }
2809         return buf;
2810 }
2811 #endif
2812
2813 /* return code: 0 for OK, 1 for syntax error */
2814 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2815 {
2816 #ifndef __U_BOOT__
2817         int i, advance=0;
2818 #else
2819         int advance=0;
2820 #endif
2821 #ifndef __U_BOOT__
2822         char sep[]=" ";
2823 #endif
2824         int ch = input->peek(input);  /* first character after the $ */
2825         debug_printf("handle_dollar: ch=%c\n",ch);
2826         if (isalpha(ch)) {
2827                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2828                 ctx->child->sp++;
2829                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2830                         b_getch(input);
2831                         b_addchr(dest,ch);
2832                 }
2833                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2834 #ifndef __U_BOOT__
2835         } else if (isdigit(ch)) {
2836                 i = ch-'0';  /* XXX is $0 special? */
2837                 if (i<global_argc) {
2838                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2839                 }
2840                 advance = 1;
2841 #endif
2842         } else switch (ch) {
2843 #ifndef __U_BOOT__
2844                 case '$':
2845                         b_adduint(dest,getpid());
2846                         advance = 1;
2847                         break;
2848                 case '!':
2849                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2850                         advance = 1;
2851                         break;
2852 #endif
2853                 case '?':
2854 #ifndef __U_BOOT__
2855                         b_adduint(dest,last_return_code);
2856 #else
2857                         ctx->child->sp++;
2858                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2859                         b_addchr(dest, '$');
2860                         b_addchr(dest, '?');
2861                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2862 #endif
2863                         advance = 1;
2864                         break;
2865 #ifndef __U_BOOT__
2866                 case '#':
2867                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2868                         advance = 1;
2869                         break;
2870 #endif
2871                 case '{':
2872                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2873                         ctx->child->sp++;
2874                         b_getch(input);
2875                         /* XXX maybe someone will try to escape the '}' */
2876                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2877                                 b_addchr(dest,ch);
2878                         }
2879                         if (ch != '}') {
2880                                 syntax();
2881                                 return 1;
2882                         }
2883                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2884                         break;
2885 #ifndef __U_BOOT__
2886                 case '(':
2887                         b_getch(input);
2888                         process_command_subs(dest, ctx, input, ')');
2889                         break;
2890                 case '*':
2891                         sep[0]=ifs[0];
2892                         for (i=1; i<global_argc; i++) {
2893                                 parse_string(dest, ctx, global_argv[i]);
2894                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2895                         }
2896                         break;
2897                 case '@':
2898                 case '-':
2899                 case '_':
2900                         /* still unhandled, but should be eventually */
2901                         error_msg("unhandled syntax: $%c",ch);
2902                         return 1;
2903                         break;
2904 #endif
2905                 default:
2906                         b_addqchr(dest,'$',dest->quote);
2907         }
2908         /* Eat the character if the flag was set.  If the compiler
2909          * is smart enough, we could substitute "b_getch(input);"
2910          * for all the "advance = 1;" above, and also end up with
2911          * a nice size-optimized program.  Hah!  That'll be the day.
2912          */
2913         if (advance) b_getch(input);
2914         return 0;
2915 }
2916
2917 #ifndef __U_BOOT__
2918 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2919 {
2920         struct in_str foo;
2921         setup_string_in_str(&foo, src);
2922         return parse_stream(dest, ctx, &foo, '\0');
2923 }
2924 #endif
2925
2926 /* return code is 0 for normal exit, 1 for syntax error */
2927 static int parse_stream(o_string *dest, struct p_context *ctx,
2928                         struct in_str *input, int end_trigger)
2929 {
2930         unsigned int ch, m;
2931 #ifndef __U_BOOT__
2932         int redir_fd;
2933         redir_type redir_style;
2934 #endif
2935         int next;
2936
2937         /* Only double-quote state is handled in the state variable dest->quote.
2938          * A single-quote triggers a bypass of the main loop until its mate is
2939          * found.  When recursing, quote state is passed in via dest->quote. */
2940
2941         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2942         while ((ch=b_getch(input))!=EOF) {
2943                 m = map[ch];
2944 #ifdef __U_BOOT__
2945                 if (input->__promptme == 0) return 1;
2946 #endif
2947                 next = (ch == '\n') ? 0 : b_peek(input);
2948
2949                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2950                         ch >= ' ' ? ch : '.', ch, m,
2951                         dest->quote, ctx->stack == NULL ? '*' : '.');
2952
2953                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2954                         b_addqchr(dest, ch, dest->quote);
2955                 } else {
2956                         if (m==2) {  /* unquoted IFS */
2957                                 if (done_word(dest, ctx)) {
2958                                         return 1;
2959                                 }
2960                                 /* If we aren't performing a substitution, treat a newline as a
2961                                  * command separator.  */
2962                                 if (end_trigger != '\0' && ch=='\n')
2963                                         done_pipe(ctx,PIPE_SEQ);
2964                         }
2965                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2966                                 debug_printf("leaving parse_stream (triggered)\n");
2967                                 return 0;
2968                         }
2969 #if 0
2970                         if (ch=='\n') {
2971                                 /* Yahoo!  Time to run with it! */
2972                                 done_pipe(ctx,PIPE_SEQ);
2973                                 run_list(ctx->list_head);
2974                                 initialize_context(ctx);
2975                         }
2976 #endif
2977                         if (m!=2) switch (ch) {
2978                 case '#':
2979                         if (dest->length == 0 && !dest->quote) {
2980                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2981                         } else {
2982                                 b_addqchr(dest, ch, dest->quote);
2983                         }
2984                         break;
2985                 case '\\':
2986                         if (next == EOF) {
2987                                 syntax();
2988                                 return 1;
2989                         }
2990                         b_addqchr(dest, '\\', dest->quote);
2991                         b_addqchr(dest, b_getch(input), dest->quote);
2992                         break;
2993                 case '$':
2994                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2995                         break;
2996                 case '\'':
2997                         dest->nonnull = 1;
2998                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2999 #ifdef __U_BOOT__
3000                                 if(input->__promptme == 0) return 1;
3001 #endif
3002                                 b_addchr(dest,ch);
3003                         }
3004                         if (ch==EOF) {
3005                                 syntax();
3006                                 return 1;
3007                         }
3008                         break;
3009                 case '"':
3010                         dest->nonnull = 1;
3011                         dest->quote = !dest->quote;
3012                         break;
3013 #ifndef __U_BOOT__
3014                 case '`':
3015                         process_command_subs(dest, ctx, input, '`');
3016                         break;
3017                 case '>':
3018                         redir_fd = redirect_opt_num(dest);
3019                         done_word(dest, ctx);
3020                         redir_style=REDIRECT_OVERWRITE;
3021                         if (next == '>') {
3022                                 redir_style=REDIRECT_APPEND;
3023                                 b_getch(input);
3024                         } else if (next == '(') {
3025                                 syntax();   /* until we support >(list) Process Substitution */
3026                                 return 1;
3027                         }
3028                         setup_redirect(ctx, redir_fd, redir_style, input);
3029                         break;
3030                 case '<':
3031                         redir_fd = redirect_opt_num(dest);
3032                         done_word(dest, ctx);
3033                         redir_style=REDIRECT_INPUT;
3034                         if (next == '<') {
3035                                 redir_style=REDIRECT_HEREIS;
3036                                 b_getch(input);
3037                         } else if (next == '>') {
3038                                 redir_style=REDIRECT_IO;
3039                                 b_getch(input);
3040                         } else if (next == '(') {
3041                                 syntax();   /* until we support <(list) Process Substitution */
3042                                 return 1;
3043                         }
3044                         setup_redirect(ctx, redir_fd, redir_style, input);
3045                         break;
3046 #endif
3047                 case ';':
3048                         done_word(dest, ctx);
3049                         done_pipe(ctx,PIPE_SEQ);
3050                         break;
3051                 case '&':
3052                         done_word(dest, ctx);
3053                         if (next=='&') {
3054                                 b_getch(input);
3055                                 done_pipe(ctx,PIPE_AND);
3056                         } else {
3057 #ifndef __U_BOOT__
3058                                 done_pipe(ctx,PIPE_BG);
3059 #else
3060                                 syntax_err();
3061                                 return 1;
3062 #endif
3063                         }
3064                         break;
3065                 case '|':
3066                         done_word(dest, ctx);
3067                         if (next=='|') {
3068                                 b_getch(input);
3069                                 done_pipe(ctx,PIPE_OR);
3070                         } else {
3071                                 /* we could pick up a file descriptor choice here
3072                                  * with redirect_opt_num(), but bash doesn't do it.
3073                                  * "echo foo 2| cat" yields "foo 2". */
3074 #ifndef __U_BOOT__
3075                                 done_command(ctx);
3076 #else
3077                                 syntax_err();
3078                                 return 1;
3079 #endif
3080                         }
3081                         break;
3082 #ifndef __U_BOOT__
3083                 case '(':
3084                 case '{':
3085                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3086                         break;
3087                 case ')':
3088                 case '}':
3089                         syntax();   /* Proper use of this character caught by end_trigger */
3090                         return 1;
3091                         break;
3092 #endif
3093                 case SUBSTED_VAR_SYMBOL:
3094                         dest->nonnull = 1;
3095                         while (ch = b_getch(input), ch != EOF &&
3096                             ch != SUBSTED_VAR_SYMBOL) {
3097                                 debug_printf("subst, pass=%d\n", ch);
3098                                 if (input->__promptme == 0)
3099                                         return 1;
3100                                 b_addchr(dest, ch);
3101                         }
3102                         debug_printf("subst, term=%d\n", ch);
3103                         if (ch == EOF) {
3104                                 syntax();
3105                                 return 1;
3106                         }
3107                         break;
3108                 default:
3109                         syntax();   /* this is really an internal logic error */
3110                         return 1;
3111                         }
3112                 }
3113         }
3114         /* complain if quote?  No, maybe we just finished a command substitution
3115          * that was quoted.  Example:
3116          * $ echo "`cat foo` plus more"
3117          * and we just got the EOF generated by the subshell that ran "cat foo"
3118          * The only real complaint is if we got an EOF when end_trigger != '\0',
3119          * that is, we were really supposed to get end_trigger, and never got
3120          * one before the EOF.  Can't use the standard "syntax error" return code,
3121          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3122         debug_printf("leaving parse_stream (EOF)\n");
3123         if (end_trigger != '\0') return -1;
3124         return 0;
3125 }
3126
3127 static void mapset(const unsigned char *set, int code)
3128 {
3129         const unsigned char *s;
3130         for (s=set; *s; s++) map[*s] = code;
3131 }
3132
3133 static void update_ifs_map(void)
3134 {
3135         /* char *ifs and char map[256] are both globals. */
3136         ifs = (uchar *)getenv("IFS");
3137         if (ifs == NULL) ifs=(uchar *)" \t\n";
3138         /* Precompute a list of 'flow through' behavior so it can be treated
3139          * quickly up front.  Computation is necessary because of IFS.
3140          * Special case handling of IFS == " \t\n" is not implemented.
3141          * The map[] array only really needs two bits each, and on most machines
3142          * that would be faster because of the reduced L1 cache footprint.
3143          */
3144         memset(map,0,sizeof(map)); /* most characters flow through always */
3145 #ifndef __U_BOOT__
3146         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3147         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3148 #else
3149         {
3150                 uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3151                 mapset(subst, 3);       /* never flow through */
3152         }
3153         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3154         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3155 #endif
3156         mapset(ifs, 2);            /* also flow through if quoted */
3157 }
3158
3159 /* most recursion does not come through here, the exeception is
3160  * from builtin_source() */
3161 static int parse_stream_outer(struct in_str *inp, int flag)
3162 {
3163
3164         struct p_context ctx;
3165         o_string temp=NULL_O_STRING;
3166         int rcode;
3167 #ifdef __U_BOOT__
3168         int code = 0;
3169 #endif
3170         do {
3171                 ctx.type = flag;
3172                 initialize_context(&ctx);
3173                 update_ifs_map();
3174                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3175                 inp->promptmode=1;
3176                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3177 #ifdef __U_BOOT__
3178                 if (rcode == 1) flag_repeat = 0;
3179 #endif
3180                 if (rcode != 1 && ctx.old_flag != 0) {
3181                         syntax();
3182 #ifdef __U_BOOT__
3183                         flag_repeat = 0;
3184 #endif
3185                 }
3186                 if (rcode != 1 && ctx.old_flag == 0) {
3187                         done_word(&temp, &ctx);
3188                         done_pipe(&ctx,PIPE_SEQ);
3189 #ifndef __U_BOOT__
3190                         run_list(ctx.list_head);
3191 #else
3192                         code = run_list(ctx.list_head);
3193                         if (code == -2) {       /* exit */
3194                                 b_free(&temp);
3195                                 code = 0;
3196                                 /* XXX hackish way to not allow exit from main loop */
3197                                 if (inp->peek == file_peek) {
3198                                         printf("exit not allowed from main input shell.\n");
3199                                         continue;
3200                                 }
3201                                 break;
3202                         }
3203                         if (code == -1)
3204                             flag_repeat = 0;
3205 #endif
3206                 } else {
3207                         if (ctx.old_flag != 0) {
3208                                 free(ctx.stack);
3209                                 b_reset(&temp);
3210                         }
3211 #ifdef __U_BOOT__
3212                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3213                         inp->__promptme = 1;
3214 #endif
3215                         temp.nonnull = 0;
3216                         temp.quote = 0;
3217                         inp->p = NULL;
3218                         free_pipe_list(ctx.list_head,0);
3219                 }
3220                 b_free(&temp);
3221         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3222 #ifndef __U_BOOT__
3223         return 0;
3224 #else
3225         return (code != 0) ? 1 : 0;
3226 #endif /* __U_BOOT__ */
3227 }
3228
3229 #ifndef __U_BOOT__
3230 static int parse_string_outer(const char *s, int flag)
3231 #else
3232 int parse_string_outer(const char *s, int flag)
3233 #endif  /* __U_BOOT__ */
3234 {
3235         struct in_str input;
3236 #ifdef __U_BOOT__
3237         char *p = NULL;
3238         int rcode;
3239         if ( !s || !*s)
3240                 return 1;
3241         if (!(p = strchr(s, '\n')) || *++p) {
3242                 p = xmalloc(strlen(s) + 2);
3243                 strcpy(p, s);
3244                 strcat(p, "\n");
3245                 setup_string_in_str(&input, p);
3246                 rcode = parse_stream_outer(&input, flag);
3247                 free(p);
3248                 return rcode;
3249         } else {
3250 #endif
3251         setup_string_in_str(&input, s);
3252         return parse_stream_outer(&input, flag);
3253 #ifdef __U_BOOT__
3254         }
3255 #endif
3256 }
3257
3258 #ifndef __U_BOOT__
3259 static int parse_file_outer(FILE *f)
3260 #else
3261 int parse_file_outer(void)
3262 #endif
3263 {
3264         int rcode;
3265         struct in_str input;
3266 #ifndef __U_BOOT__
3267         setup_file_in_str(&input, f);
3268 #else
3269         setup_file_in_str(&input);
3270 #endif
3271         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3272         return rcode;
3273 }
3274
3275 #ifdef __U_BOOT__
3276 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3277 static void u_boot_hush_reloc(void)
3278 {
3279         unsigned long addr;
3280         struct reserved_combo *r;
3281
3282         for (r=reserved_list; r<reserved_list+NRES; r++) {
3283                 addr = (ulong) (r->literal) + gd->reloc_off;
3284                 r->literal = (char *)addr;
3285         }
3286 }
3287 #endif
3288
3289 int u_boot_hush_start(void)
3290 {
3291         if (top_vars == NULL) {
3292                 top_vars = malloc(sizeof(struct variables));
3293                 top_vars->name = "HUSH_VERSION";
3294                 top_vars->value = "0.01";
3295                 top_vars->next = NULL;
3296                 top_vars->flg_export = 0;
3297                 top_vars->flg_read_only = 1;
3298 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3299                 u_boot_hush_reloc();
3300 #endif
3301         }
3302         return 0;
3303 }
3304
3305 static void *xmalloc(size_t size)
3306 {
3307         void *p = NULL;
3308
3309         if (!(p = malloc(size))) {
3310             printf("ERROR : memory not allocated\n");
3311             for(;;);
3312         }
3313         return p;
3314 }
3315
3316 static void *xrealloc(void *ptr, size_t size)
3317 {
3318         void *p = NULL;
3319
3320         if (!(p = realloc(ptr, size))) {
3321             printf("ERROR : memory not allocated\n");
3322             for(;;);
3323         }
3324         return p;
3325 }
3326 #endif /* __U_BOOT__ */
3327
3328 #ifndef __U_BOOT__
3329 /* Make sure we have a controlling tty.  If we get started under a job
3330  * aware app (like bash for example), make sure we are now in charge so
3331  * we don't fight over who gets the foreground */
3332 static void setup_job_control(void)
3333 {
3334         static pid_t shell_pgrp;
3335         /* Loop until we are in the foreground.  */
3336         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3337                 kill (- shell_pgrp, SIGTTIN);
3338
3339         /* Ignore interactive and job-control signals.  */
3340         signal(SIGINT, SIG_IGN);
3341         signal(SIGQUIT, SIG_IGN);
3342         signal(SIGTERM, SIG_IGN);
3343         signal(SIGTSTP, SIG_IGN);
3344         signal(SIGTTIN, SIG_IGN);
3345         signal(SIGTTOU, SIG_IGN);
3346         signal(SIGCHLD, SIG_IGN);
3347
3348         /* Put ourselves in our own process group.  */
3349         setsid();
3350         shell_pgrp = getpid ();
3351         setpgid (shell_pgrp, shell_pgrp);
3352
3353         /* Grab control of the terminal.  */
3354         tcsetpgrp(shell_terminal, shell_pgrp);
3355 }
3356
3357 int hush_main(int argc, char * const *argv)
3358 {
3359         int opt;
3360         FILE *input;
3361         char **e = environ;
3362
3363         /* XXX what should these be while sourcing /etc/profile? */
3364         global_argc = argc;
3365         global_argv = argv;
3366
3367         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3368          * hush_main(), therefore we cannot rely on the BSS to zero out this
3369          * stuff.  Reset these to 0 every time. */
3370         ifs = NULL;
3371         /* map[] is taken care of with call to update_ifs_map() */
3372         fake_mode = 0;
3373         interactive = 0;
3374         close_me_head = NULL;
3375         last_bg_pid = 0;
3376         job_list = NULL;
3377         last_jobid = 0;
3378
3379         /* Initialize some more globals to non-zero values */
3380         set_cwd();
3381 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3382         cmdedit_set_initial_prompt();
3383 #else
3384         PS1 = NULL;
3385 #endif
3386         PS2 = "> ";
3387
3388         /* initialize our shell local variables with the values
3389          * currently living in the environment */
3390         if (e) {
3391                 for (; *e; e++)
3392                         set_local_var(*e, 2);   /* without call putenv() */
3393         }
3394
3395         last_return_code=EXIT_SUCCESS;
3396
3397
3398         if (argv[0] && argv[0][0] == '-') {
3399                 debug_printf("\nsourcing /etc/profile\n");
3400                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3401                         mark_open(fileno(input));
3402                         parse_file_outer(input);
3403                         mark_closed(fileno(input));
3404                         fclose(input);
3405                 }
3406         }
3407         input=stdin;
3408
3409         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3410                 switch (opt) {
3411                         case 'c':
3412                                 {
3413                                         global_argv = argv+optind;
3414                                         global_argc = argc-optind;
3415                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3416                                         goto final_return;
3417                                 }
3418                                 break;
3419                         case 'i':
3420                                 interactive++;
3421                                 break;
3422                         case 'f':
3423                                 fake_mode++;
3424                                 break;
3425                         default:
3426 #ifndef BB_VER
3427                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3428                                                 "   or: sh -c command [args]...\n\n");
3429                                 exit(EXIT_FAILURE);
3430 #else
3431                                 show_usage();
3432 #endif
3433                 }
3434         }
3435         /* A shell is interactive if the `-i' flag was given, or if all of
3436          * the following conditions are met:
3437          *        no -c command
3438          *    no arguments remaining or the -s flag given
3439          *    standard input is a terminal
3440          *    standard output is a terminal
3441          *    Refer to Posix.2, the description of the `sh' utility. */
3442         if (argv[optind]==NULL && input==stdin &&
3443                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3444                 interactive++;
3445         }
3446
3447         debug_printf("\ninteractive=%d\n", interactive);
3448         if (interactive) {
3449                 /* Looks like they want an interactive shell */
3450 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3451                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3452                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3453 #endif
3454                 setup_job_control();
3455         }
3456
3457         if (argv[optind]==NULL) {
3458                 opt=parse_file_outer(stdin);
3459                 goto final_return;
3460         }
3461
3462         debug_printf("\nrunning script '%s'\n", argv[optind]);
3463         global_argv = argv+optind;
3464         global_argc = argc-optind;
3465         input = xfopen(argv[optind], "r");
3466         opt = parse_file_outer(input);
3467
3468 #ifdef CONFIG_FEATURE_CLEAN_UP
3469         fclose(input);
3470         if (cwd && cwd != unknown)
3471                 free((char*)cwd);
3472         {
3473                 struct variables *cur, *tmp;
3474                 for(cur = top_vars; cur; cur = tmp) {
3475                         tmp = cur->next;
3476                         if (!cur->flg_read_only) {
3477                                 free(cur->name);
3478                                 free(cur->value);
3479                                 free(cur);
3480                         }
3481                 }
3482         }
3483 #endif
3484
3485 final_return:
3486         return(opt?opt:last_return_code);
3487 }
3488 #endif
3489
3490 static char *insert_var_value(char *inp)
3491 {
3492         return insert_var_value_sub(inp, 0);
3493 }
3494
3495 static char *insert_var_value_sub(char *inp, int tag_subst)
3496 {
3497         int res_str_len = 0;
3498         int len;
3499         int done = 0;
3500         char *p, *p1, *res_str = NULL;
3501
3502         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3503                 /* check the beginning of the string for normal charachters */
3504                 if (p != inp) {
3505                         /* copy any charachters to the result string */
3506                         len = p - inp;
3507                         res_str = xrealloc(res_str, (res_str_len + len));
3508                         strncpy((res_str + res_str_len), inp, len);
3509                         res_str_len += len;
3510                 }
3511                 inp = ++p;
3512                 /* find the ending marker */
3513                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3514                 *p = '\0';
3515                 /* look up the value to substitute */
3516                 if ((p1 = lookup_param(inp))) {
3517                         if (tag_subst)
3518                                 len = res_str_len + strlen(p1) + 2;
3519                         else
3520                                 len = res_str_len + strlen(p1);
3521                         res_str = xrealloc(res_str, (1 + len));
3522                         if (tag_subst) {
3523                                 /*
3524                                  * copy the variable value to the result
3525                                  * string
3526                                  */
3527                                 strcpy((res_str + res_str_len + 1), p1);
3528
3529                                 /*
3530                                  * mark the replaced text to be accepted as
3531                                  * is
3532                                  */
3533                                 res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3534                                 res_str[res_str_len + 1 + strlen(p1)] =
3535                                         SUBSTED_VAR_SYMBOL;
3536                         } else
3537                                 /*
3538                                  * copy the variable value to the result
3539                                  * string
3540                                  */
3541                                 strcpy((res_str + res_str_len), p1);
3542
3543                         res_str_len = len;
3544                 }
3545                 *p = SPECIAL_VAR_SYMBOL;
3546                 inp = ++p;
3547                 done = 1;
3548         }
3549         if (done) {
3550                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3551                 strcpy((res_str + res_str_len), inp);
3552                 while ((p = strchr(res_str, '\n'))) {
3553                         *p = ' ';
3554                 }
3555         }
3556         return (res_str == NULL) ? inp : res_str;
3557 }
3558
3559 static char **make_list_in(char **inp, char *name)
3560 {
3561         int len, i;
3562         int name_len = strlen(name);
3563         int n = 0;
3564         char **list;
3565         char *p1, *p2, *p3;
3566
3567         /* create list of variable values */
3568         list = xmalloc(sizeof(*list));
3569         for (i = 0; inp[i]; i++) {
3570                 p3 = insert_var_value(inp[i]);
3571                 p1 = p3;
3572                 while (*p1) {
3573                         if ((*p1 == ' ')) {
3574                                 p1++;
3575                                 continue;
3576                         }
3577                         if ((p2 = strchr(p1, ' '))) {
3578                                 len = p2 - p1;
3579                         } else {
3580                                 len = strlen(p1);
3581                                 p2 = p1 + len;
3582                         }
3583                         /* we use n + 2 in realloc for list,because we add
3584                          * new element and then we will add NULL element */
3585                         list = xrealloc(list, sizeof(*list) * (n + 2));
3586                         list[n] = xmalloc(2 + name_len + len);
3587                         strcpy(list[n], name);
3588                         strcat(list[n], "=");
3589                         strncat(list[n], p1, len);
3590                         list[n++][name_len + len + 1] = '\0';
3591                         p1 = p2;
3592                 }
3593                 if (p3 != inp[i]) free(p3);
3594         }
3595         list[n] = NULL;
3596         return list;
3597 }
3598
3599 /* Make new string for parser */
3600 static char * make_string(char ** inp)
3601 {
3602         char *p;
3603         char *str = NULL;
3604         int n;
3605         int len = 2;
3606         char *noeval_str;
3607         int noeval = 0;
3608
3609         noeval_str = get_local_var("HUSH_NO_EVAL");
3610         if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3611                 noeval = 1;
3612         for (n = 0; inp[n]; n++) {
3613                 p = insert_var_value_sub(inp[n], noeval);
3614                 str = xrealloc(str, (len + strlen(p)));
3615                 if (n) {
3616                         strcat(str, " ");
3617                 } else {
3618                         *str = '\0';
3619                 }
3620                 strcat(str, p);
3621                 len = strlen(str) + 3;
3622                 if (p != inp[n]) free(p);
3623         }
3624         len = strlen(str);
3625         *(str + len) = '\n';
3626         *(str + len + 1) = '\0';
3627         return str;
3628 }
3629
3630 #ifdef __U_BOOT__
3631 static int do_showvar(cmd_tbl_t *cmdtp, int flag, int argc,
3632                       char * const argv[])
3633 {
3634         int i, k;
3635         int rcode = 0;
3636         struct variables *cur;
3637
3638         if (argc == 1) {                /* Print all env variables      */
3639                 for (cur = top_vars; cur; cur = cur->next) {
3640                         printf ("%s=%s\n", cur->name, cur->value);
3641                         if (ctrlc ()) {
3642                                 puts ("\n ** Abort\n");
3643                                 return 1;
3644                         }
3645                 }
3646                 return 0;
3647         }
3648         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3649                 char *name = argv[i];
3650
3651                 k = -1;
3652                 for (cur = top_vars; cur; cur = cur->next) {
3653                         if(strcmp (cur->name, name) == 0) {
3654                                 k = 0;
3655                                 printf ("%s=%s\n", cur->name, cur->value);
3656                         }
3657                         if (ctrlc ()) {
3658                                 puts ("\n ** Abort\n");
3659                                 return 1;
3660                         }
3661                 }
3662                 if (k < 0) {
3663                         printf ("## Error: \"%s\" not defined\n", name);
3664                         rcode ++;
3665                 }
3666         }
3667         return rcode;
3668 }
3669
3670 U_BOOT_CMD(
3671         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3672         "print local hushshell variables",
3673         "\n    - print values of all hushshell variables\n"
3674         "showvar name ...\n"
3675         "    - print value of hushshell variable 'name'"
3676 );
3677
3678 #endif
3679 /****************************************************************************/