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  *      simple_itoa() was lifted from boa-0.93.15
  21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  23  *        and many builtins derived from contributions by Erik Andersen
  24  *      miscellaneous bugfixes from Matt Kraai
  25  *
  26  * There are two big (and related) architecture differences between
  27  * this parser and the lash parser.  One is that this version is
  28  * actually designed from the ground up to understand nearly all
  29  * of the Bourne grammar.  The second, consequential change is that
  30  * the parser and input reader have been turned inside out.  Now,
  31  * the parser is in control, and asks for input as needed.  The old
  32  * way had the input reader in control, and it asked for parsing to
  33  * take place as needed.  The new way makes it much easier to properly
  34  * handle the recursion implicit in the various substitutions, especially
  35  * across continuation lines.
  36  *
  37  * Bash grammar not implemented: (how many of these were in original sh?)
  38  *      $@ (those sure look like weird quoting rules)
  39  *      $_
  40  *      ! negation operator for pipes
  41  *      &> and >& redirection of stdout+stderr
  42  *      Brace Expansion
  43  *      Tilde Expansion
  44  *      fancy forms of Parameter Expansion
  45  *      aliases
  46  *      Arithmetic Expansion
  47  *      <(list) and >(list) Process Substitution
  48  *      reserved words: case, esac, select, function
  49  *      Here Documents ( << word )
  50  *      Functions
  51  * Major bugs:
  52  *      job handling woefully incomplete and buggy
  53  *      reserved word execution woefully incomplete and buggy
  54  * to-do:
  55  *      port selected bugfixes from post-0.49 busybox lash - done?
  56  *      finish implementing reserved words: for, while, until, do, done
  57  *      change { and } from special chars to reserved words
  58  *      builtins: break, continue, eval, return, set, trap, ulimit
  59  *      test magic exec
  60  *      handle children going into background
  61  *      clean up recognition of null pipes
  62  *      check setting of global_argc and global_argv
  63  *      control-C handling, probably with longjmp
  64  *      follow IFS rules more precisely, including update semantics
  65  *      figure out what to do with backslash-newline
  66  *      explain why we use signal instead of sigaction
  67  *      propagate syntax errors, die on resource errors?
  68  *      continuation lines, both explicit and implicit - done?
  69  *      memory leak finding and plugging - done?
  70  *      more testing, especially quoting rules and redirection
  71  *      document how quoting rules not precisely followed for variable assignments
  72  *      maybe change map[] to use 2-bit entries
  73  *      (eventually) remove all the printf's
  74  *
  75  * This program is free software; you can redistribute it and/or modify
  76  * it under the terms of the GNU General Public License as published by
  77  * the Free Software Foundation; either version 2 of the License, or
  78  * (at your option) any later version.
  79  *
  80  * This program is distributed in the hope that it will be useful,
  81  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  82  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  83  * General Public License for more details.
  84  *
  85  * You should have received a copy of the GNU General Public License
  86  * along with this program; if not, write to the Free Software
  87  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  88  */
  89 #define __U_BOOT__
  90 #ifdef __U_BOOT__
  91 #include <malloc.h>         /* malloc, free, realloc*/
  92 #include <linux/ctype.h>    /* isalpha, isdigit */
  93 #include <common.h>        /* readline */
  94 #include <hush.h>
  95 #include <command.h>        /* find_cmd */
  96 /*cmd_boot.c*/
  97 extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);      /* do_bootd */
  98 #endif
  99 #ifdef CFG_HUSH_PARSER
 100 #ifndef __U_BOOT__
 101 #include <ctype.h>     /* isalpha, isdigit */
 102 #include <unistd.h>    /* getpid */
 103 #include <stdlib.h>    /* getenv, atoi */
 104 #include <string.h>    /* strchr */
 105 #include <stdio.h>     /* popen etc. */
 106 #include <glob.h>      /* glob, of course */
 107 #include <stdarg.h>    /* va_list */
 108 #include <errno.h>
 109 #include <fcntl.h>
 110 #include <getopt.h>    /* should be pretty obvious */
 111
 112 #include <sys/stat.h>  /* ulimit */
 113 #include <sys/types.h>
 114 #include <sys/wait.h>
 115 #include <signal.h>
 116
 117 /* #include <dmalloc.h> */
 118 /* #define DEBUG_SHELL */
 119
 120 #if 1
 121 #include "busybox.h"
 122 #include "cmdedit.h"
 123 #else
 124 #define applet_name "hush"
 125 #include "standalone.h"
 126 #define hush_main main
 127 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 128 #define BB_BANNER
 129 #endif
 130 #endif
 131 #define SPECIAL_VAR_SYMBOL 03
 132 #ifndef __U_BOOT__
 133 #define FLAG_EXIT_FROM_LOOP 1
 134 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 135 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 136
 137 #endif
 138
 139 #ifdef __U_BOOT__
 140 DECLARE_GLOBAL_DATA_PTR;
 141
 142 #define EXIT_SUCCESS 0
 143 #define EOF -1
 144 #define syntax() syntax_err()
 145 #define xstrdup strdup
 146 #define error_msg printf
 147 #else
 148 typedef enum {
 149         REDIRECT_INPUT     = 1,
 150         REDIRECT_OVERWRITE = 2,
 151         REDIRECT_APPEND    = 3,
 152         REDIRECT_HEREIS    = 4,
 153         REDIRECT_IO        = 5
 154 } redir_type;
 155
 156 /* The descrip member of this structure is only used to make debugging
 157  * output pretty */
 158 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 159         { 0,                         0, "()" },
 160         { O_RDONLY,                  0, "<"  },
 161         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 162         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 163         { O_RDONLY,                 -1, "<<" },
 164         { O_RDWR,                    1, "<>" }
 165 };
 166 #endif
 167
 168 typedef enum {
 169         PIPE_SEQ = 1,
 170         PIPE_AND = 2,
 171         PIPE_OR  = 3,
 172         PIPE_BG  = 4,
 173 } pipe_style;
 174
 175 /* might eventually control execution */
 176 typedef enum {
 177         RES_NONE  = 0,
 178         RES_IF    = 1,
 179         RES_THEN  = 2,
 180         RES_ELIF  = 3,
 181         RES_ELSE  = 4,
 182         RES_FI    = 5,
 183         RES_FOR   = 6,
 184         RES_WHILE = 7,
 185         RES_UNTIL = 8,
 186         RES_DO    = 9,
 187         RES_DONE  = 10,
 188         RES_XXXX  = 11,
 189         RES_IN    = 12,
 190         RES_SNTX  = 13
 191 } reserved_style;
 192 #define FLAG_END   (1<<RES_NONE)
 193 #define FLAG_IF    (1<<RES_IF)
 194 #define FLAG_THEN  (1<<RES_THEN)
 195 #define FLAG_ELIF  (1<<RES_ELIF)
 196 #define FLAG_ELSE  (1<<RES_ELSE)
 197 #define FLAG_FI    (1<<RES_FI)
 198 #define FLAG_FOR   (1<<RES_FOR)
 199 #define FLAG_WHILE (1<<RES_WHILE)
 200 #define FLAG_UNTIL (1<<RES_UNTIL)
 201 #define FLAG_DO    (1<<RES_DO)
 202 #define FLAG_DONE  (1<<RES_DONE)
 203 #define FLAG_IN    (1<<RES_IN)
 204 #define FLAG_START (1<<RES_XXXX)
 205
 206 /* This holds pointers to the various results of parsing */
 207 struct p_context {
 208         struct child_prog *child;
 209         struct pipe *list_head;
 210         struct pipe *pipe;
 211 #ifndef __U_BOOT__
 212         struct redir_struct *pending_redirect;
 213 #endif
 214         reserved_style w;
 215         int old_flag;                           /* for figuring out valid reserved words */
 216         struct p_context *stack;
 217         int type;                       /* define type of parser : ";$" common or special symbol */
 218         /* How about quoting status? */
 219 };
 220
 221 #ifndef __U_BOOT__
 222 struct redir_struct {
 223         redir_type type;                        /* type of redirection */
 224         int fd;                                         /* file descriptor being redirected */
 225         int dup;                                        /* -1, or file descriptor being duplicated */
 226         struct redir_struct *next;      /* pointer to the next redirect in the list */
 227         glob_t word;                            /* *word.gl_pathv is the filename */
 228 };
 229 #endif
 230
 231 struct child_prog {
 232 #ifndef __U_BOOT__
 233         pid_t pid;                                      /* 0 if exited */
 234 #endif
 235         char **argv;                            /* program name and arguments */
 236 #ifdef __U_BOOT__
 237         int    argc;                            /* number of program arguments */
 238 #endif
 239         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 240 #ifndef __U_BOOT__
 241         int subshell;                           /* flag, non-zero if group must be forked */
 242         struct redir_struct *redirects; /* I/O redirections */
 243         glob_t glob_result;                     /* result of parameter globbing */
 244         int is_stopped;                         /* is the program currently running? */
 245         struct pipe *family;            /* pointer back to the child's parent pipe */
 246 #endif
 247         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 248         int type;
 249 };
 250
 251 struct pipe {
 252 #ifndef __U_BOOT__
 253         int jobid;                                      /* job number */
 254 #endif
 255         int num_progs;                          /* total number of programs in job */
 256 #ifndef __U_BOOT__
 257         int running_progs;                      /* number of programs running */
 258         char *text;                                     /* name of job */
 259         char *cmdbuf;                           /* buffer various argv's point into */
 260         pid_t pgrp;                                     /* process group ID for the job */
 261 #endif
 262         struct child_prog *progs;       /* array of commands in pipe */
 263         struct pipe *next;                      /* to track background commands */
 264 #ifndef __U_BOOT__
 265         int stopped_progs;                      /* number of programs alive, but stopped */
 266         int job_context;                        /* bitmask defining current context */
 267 #endif
 268         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 269         reserved_style r_mode;          /* supports if, for, while, until */
 270 };
 271
 272 #ifndef __U_BOOT__
 273 struct close_me {
 274         int fd;
 275         struct close_me *next;
 276 };
 277 #endif
 278
 279 struct variables {
 280         char *name;
 281         char *value;
 282         int flg_export;
 283         int flg_read_only;
 284         struct variables *next;
 285 };
 286
 287 /* globals, connect us to the outside world
 288  * the first three support $?, $#, and $1 */
 289 #ifndef __U_BOOT__
 290 char **global_argv;
 291 unsigned int global_argc;
 292 #endif
 293 unsigned int last_return_code;
 294 int nesting_level;
 295 #ifndef __U_BOOT__
 296 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 297 #endif
 298
 299 /* "globals" within this file */
 300 static uchar *ifs;
 301 static char map[256];
 302 #ifndef __U_BOOT__
 303 static int fake_mode;
 304 static int interactive;
 305 static struct close_me *close_me_head;
 306 static const char *cwd;
 307 static struct pipe *job_list;
 308 static unsigned int last_bg_pid;
 309 static unsigned int last_jobid;
 310 static unsigned int shell_terminal;
 311 static char *PS1;
 312 static char *PS2;
 313 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 314 struct variables *top_vars = &shell_ver;
 315 #else
 316 static int flag_repeat = 0;
 317 static int do_repeat = 0;
 318 static struct variables *top_vars = NULL ;
 319 #endif /*__U_BOOT__ */
 320
 321 #define B_CHUNK (100)
 322 #define B_NOSPAC 1
 323
 324 typedef struct {
 325         char *data;
 326         int length;
 327         int maxlen;
 328         int quote;
 329         int nonnull;
 330 } o_string;
 331 #define NULL_O_STRING {NULL,0,0,0,0}
 332 /* used for initialization:
 333         o_string foo = NULL_O_STRING; */
 334
 335 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 336  * available?  Where is it documented? */
 337 struct in_str {
 338         const char *p;
 339 #ifndef __U_BOOT__
 340         char peek_buf[2];
 341 #endif
 342         int __promptme;
 343         int promptmode;
 344 #ifndef __U_BOOT__
 345         FILE *file;
 346 #endif
 347         int (*get) (struct in_str *);
 348         int (*peek) (struct in_str *);
 349 };
 350 #define b_getch(input) ((input)->get(input))
 351 #define b_peek(input) ((input)->peek(input))
 352
 353 #ifndef __U_BOOT__
 354 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 355
 356 struct built_in_command {
 357         char *cmd;                                      /* name */
 358         char *descr;                            /* description */
 359         int (*function) (struct child_prog *);  /* function ptr */
 360 };
 361 #endif
 362
 363 /* This should be in utility.c */
 364 #ifdef DEBUG_SHELL
 365 #ifndef __U_BOOT__
 366 static void debug_printf(const char *format, ...)
 367 {
 368         va_list args;
 369         va_start(args, format);
 370         vfprintf(stderr, format, args);
 371         va_end(args);
 372 }
 373 #else
 374 #define debug_printf printf             /* U-Boot debug flag */
 375 #endif
 376 #else
 377 static inline void debug_printf(const char *format, ...) { }
 378 #endif
 379 #define final_printf debug_printf
 380
 381 #ifdef __U_BOOT__
 382 static void syntax_err(void) {
 383          printf("syntax error\n");
 384 }
 385 #else
 386 static void __syntax(char *file, int line) {
 387         error_msg("syntax error %s:%d", file, line);
 388 }
 389 #define syntax() __syntax(__FILE__, __LINE__)
 390 #endif
 391
 392 #ifdef __U_BOOT__
 393 static void *xmalloc(size_t size);
 394 static void *xrealloc(void *ptr, size_t size);
 395 #else
 396 /* Index of subroutines: */
 397 /*   function prototypes for builtins */
 398 static int builtin_cd(struct child_prog *child);
 399 static int builtin_env(struct child_prog *child);
 400 static int builtin_eval(struct child_prog *child);
 401 static int builtin_exec(struct child_prog *child);
 402 static int builtin_exit(struct child_prog *child);
 403 static int builtin_export(struct child_prog *child);
 404 static int builtin_fg_bg(struct child_prog *child);
 405 static int builtin_help(struct child_prog *child);
 406 static int builtin_jobs(struct child_prog *child);
 407 static int builtin_pwd(struct child_prog *child);
 408 static int builtin_read(struct child_prog *child);
 409 static int builtin_set(struct child_prog *child);
 410 static int builtin_shift(struct child_prog *child);
 411 static int builtin_source(struct child_prog *child);
 412 static int builtin_umask(struct child_prog *child);
 413 static int builtin_unset(struct child_prog *child);
 414 static int builtin_not_written(struct child_prog *child);
 415 #endif
 416 /*   o_string manipulation: */
 417 static int b_check_space(o_string *o, int len);
 418 static int b_addchr(o_string *o, int ch);
 419 static void b_reset(o_string *o);
 420 static int b_addqchr(o_string *o, int ch, int quote);
 421 #ifndef __U_BOOT__
 422 static int b_adduint(o_string *o, unsigned int i);
 423 #endif
 424 /*  in_str manipulations: */
 425 static int static_get(struct in_str *i);
 426 static int static_peek(struct in_str *i);
 427 static int file_get(struct in_str *i);
 428 static int file_peek(struct in_str *i);
 429 #ifndef __U_BOOT__
 430 static void setup_file_in_str(struct in_str *i, FILE *f);
 431 #else
 432 static void setup_file_in_str(struct in_str *i);
 433 #endif
 434 static void setup_string_in_str(struct in_str *i, const char *s);
 435 #ifndef __U_BOOT__
 436 /*  close_me manipulations: */
 437 static void mark_open(int fd);
 438 static void mark_closed(int fd);
 439 static void close_all(void);
 440 #endif
 441 /*  "run" the final data structures: */
 442 static char *indenter(int i);
 443 static int free_pipe_list(struct pipe *head, int indent);
 444 static int free_pipe(struct pipe *pi, int indent);
 445 /*  really run the final data structures: */
 446 #ifndef __U_BOOT__
 447 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 448 #endif
 449 static int run_list_real(struct pipe *pi);
 450 #ifndef __U_BOOT__
 451 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 452 #endif
 453 static int run_pipe_real(struct pipe *pi);
 454 /*   extended glob support: */
 455 #ifndef __U_BOOT__
 456 static int globhack(const char *src, int flags, glob_t *pglob);
 457 static int glob_needed(const char *s);
 458 static int xglob(o_string *dest, int flags, glob_t *pglob);
 459 #endif
 460 /*   variable assignment: */
 461 static int is_assignment(const char *s);
 462 /*   data structure manipulation: */
 463 #ifndef __U_BOOT__
 464 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 465 #endif
 466 static void initialize_context(struct p_context *ctx);
 467 static int done_word(o_string *dest, struct p_context *ctx);
 468 static int done_command(struct p_context *ctx);
 469 static int done_pipe(struct p_context *ctx, pipe_style type);
 470 /*   primary string parsing: */
 471 #ifndef __U_BOOT__
 472 static int redirect_dup_num(struct in_str *input);
 473 static int redirect_opt_num(o_string *o);
 474 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 475 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 476 #endif
 477 static char *lookup_param(char *src);
 478 static char *make_string(char **inp);
 479 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 480 #ifndef __U_BOOT__
 481 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 482 #endif
 483 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 484 /*   setup: */
 485 static int parse_stream_outer(struct in_str *inp, int flag);
 486 #ifndef __U_BOOT__
 487 static int parse_string_outer(const char *s, int flag);
 488 static int parse_file_outer(FILE *f);
 489 #endif
 490 #ifndef __U_BOOT__
 491 /*   job management: */
 492 static int checkjobs(struct pipe* fg_pipe);
 493 static void insert_bg_job(struct pipe *pi);
 494 static void remove_bg_job(struct pipe *pi);
 495 #endif
 496 /*     local variable support */
 497 static char **make_list_in(char **inp, char *name);
 498 static char *insert_var_value(char *inp);
 499 static char *get_local_var(const char *var);
 500 #ifndef __U_BOOT__
 501 static void  unset_local_var(const char *name);
 502 #endif
 503 static int set_local_var(const char *s, int flg_export);
 504
 505 #ifndef __U_BOOT__
 506 /* Table of built-in functions.  They can be forked or not, depending on
 507  * context: within pipes, they fork.  As simple commands, they do not.
 508  * When used in non-forking context, they can change global variables
 509  * in the parent shell process.  If forked, of course they can not.
 510  * For example, 'unset foo | whatever' will parse and run, but foo will
 511  * still be set at the end. */
 512 static struct built_in_command bltins[] = {
 513         {"bg", "Resume a job in the background", builtin_fg_bg},
 514         {"break", "Exit for, while or until loop", builtin_not_written},
 515         {"cd", "Change working directory", builtin_cd},
 516         {"continue", "Continue for, while or until loop", builtin_not_written},
 517         {"env", "Print all environment variables", builtin_env},
 518         {"eval", "Construct and run shell command", builtin_eval},
 519         {"exec", "Exec command, replacing this shell with the exec'd process",
 520                 builtin_exec},
 521         {"exit", "Exit from shell()", builtin_exit},
 522         {"export", "Set environment variable", builtin_export},
 523         {"fg", "Bring job into the foreground", builtin_fg_bg},
 524         {"jobs", "Lists the active jobs", builtin_jobs},
 525         {"pwd", "Print current directory", builtin_pwd},
 526         {"read", "Input environment variable", builtin_read},
 527         {"return", "Return from a function", builtin_not_written},
 528         {"set", "Set/unset shell local variables", builtin_set},
 529         {"shift", "Shift positional parameters", builtin_shift},
 530         {"trap", "Trap signals", builtin_not_written},
 531         {"ulimit","Controls resource limits", builtin_not_written},
 532         {"umask","Sets file creation mask", builtin_umask},
 533         {"unset", "Unset environment variable", builtin_unset},
 534         {".", "Source-in and run commands in a file", builtin_source},
 535         {"help", "List shell built-in commands", builtin_help},
 536         {NULL, NULL, NULL}
 537 };
 538
 539 static const char *set_cwd(void)
 540 {
 541         if(cwd==unknown)
 542                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 543         cwd = xgetcwd((char *)cwd);
 544         if (!cwd)
 545                 cwd = unknown;
 546         return cwd;
 547 }
 548
 549 /* built-in 'eval' handler */
 550 static int builtin_eval(struct child_prog *child)
 551 {
 552         char *str = NULL;
 553         int rcode = EXIT_SUCCESS;
 554
 555         if (child->argv[1]) {
 556                 str = make_string(child->argv + 1);
 557                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 558                                         FLAG_PARSE_SEMICOLON);
 559                 free(str);
 560                 rcode = last_return_code;
 561         }
 562         return rcode;
 563 }
 564
 565 /* built-in 'cd <path>' handler */
 566 static int builtin_cd(struct child_prog *child)
 567 {
 568         char *newdir;
 569         if (child->argv[1] == NULL)
 570                 newdir = getenv("HOME");
 571         else
 572                 newdir = child->argv[1];
 573         if (chdir(newdir)) {
 574                 printf("cd: %s: %s\n", newdir, strerror(errno));
 575                 return EXIT_FAILURE;
 576         }
 577         set_cwd();
 578         return EXIT_SUCCESS;
 579 }
 580
 581 /* built-in 'env' handler */
 582 static int builtin_env(struct child_prog *dummy)
 583 {
 584         char **e = environ;
 585         if (e == NULL) return EXIT_FAILURE;
 586         for (; *e; e++) {
 587                 puts(*e);
 588         }
 589         return EXIT_SUCCESS;
 590 }
 591
 592 /* built-in 'exec' handler */
 593 static int builtin_exec(struct child_prog *child)
 594 {
 595         if (child->argv[1] == NULL)
 596                 return EXIT_SUCCESS;   /* Really? */
 597         child->argv++;
 598         pseudo_exec(child);
 599         /* never returns */
 600 }
 601
 602 /* built-in 'exit' handler */
 603 static int builtin_exit(struct child_prog *child)
 604 {
 605         if (child->argv[1] == NULL)
 606                 exit(last_return_code);
 607         exit (atoi(child->argv[1]));
 608 }
 609
 610 /* built-in 'export VAR=value' handler */
 611 static int builtin_export(struct child_prog *child)
 612 {
 613         int res = 0;
 614         char *name = child->argv[1];
 615
 616         if (name == NULL) {
 617                 return (builtin_env(child));
 618         }
 619
 620         name = strdup(name);
 621
 622         if(name) {
 623                 char *value = strchr(name, '=');
 624
 625                 if (!value) {
 626                         char *tmp;
 627                         /* They are exporting something without an =VALUE */
 628
 629                         value = get_local_var(name);
 630                         if (value) {
 631                                 size_t ln = strlen(name);
 632
 633                                 tmp = realloc(name, ln+strlen(value)+2);
 634                                 if(tmp==NULL)
 635                                         res = -1;
 636                                 else {
 637                                         sprintf(tmp+ln, "=%s", value);
 638                                         name = tmp;
 639                                 }
 640                         } else {
 641                                 /* bash does not return an error when trying to export
 642                                  * an undefined variable.  Do likewise. */
 643                                 res = 1;
 644                         }
 645                 }
 646         }
 647         if (res<0)
 648                 perror_msg("export");
 649         else if(res==0)
 650                 res = set_local_var(name, 1);
 651         else
 652                 res = 0;
 653         free(name);
 654         return res;
 655 }
 656
 657 /* built-in 'fg' and 'bg' handler */
 658 static int builtin_fg_bg(struct child_prog *child)
 659 {
 660         int i, jobnum;
 661         struct pipe *pi=NULL;
 662
 663         if (!interactive)
 664                 return EXIT_FAILURE;
 665         /* If they gave us no args, assume they want the last backgrounded task */
 666         if (!child->argv[1]) {
 667                 for (pi = job_list; pi; pi = pi->next) {
 668                         if (pi->jobid == last_jobid) {
 669                                 break;
 670                         }
 671                 }
 672                 if (!pi) {
 673                         error_msg("%s: no current job", child->argv[0]);
 674                         return EXIT_FAILURE;
 675                 }
 676         } else {
 677                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 678                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 679                         return EXIT_FAILURE;
 680                 }
 681                 for (pi = job_list; pi; pi = pi->next) {
 682                         if (pi->jobid == jobnum) {
 683                                 break;
 684                         }
 685                 }
 686                 if (!pi) {
 687                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 688                         return EXIT_FAILURE;
 689                 }
 690         }
 691
 692         if (*child->argv[0] == 'f') {
 693                 /* Put the job into the foreground.  */
 694                 tcsetpgrp(shell_terminal, pi->pgrp);
 695         }
 696
 697         /* Restart the processes in the job */
 698         for (i = 0; i < pi->num_progs; i++)
 699                 pi->progs[i].is_stopped = 0;
 700
 701         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 702                 if (i == ESRCH) {
 703                         remove_bg_job(pi);
 704                 } else {
 705                         perror_msg("kill (SIGCONT)");
 706                 }
 707         }
 708
 709         pi->stopped_progs = 0;
 710         return EXIT_SUCCESS;
 711 }
 712
 713 /* built-in 'help' handler */
 714 static int builtin_help(struct child_prog *dummy)
 715 {
 716         struct built_in_command *x;
 717
 718         printf("\nBuilt-in commands:\n");
 719         printf("-------------------\n");
 720         for (x = bltins; x->cmd; x++) {
 721                 if (x->descr==NULL)
 722                         continue;
 723                 printf("%s\t%s\n", x->cmd, x->descr);
 724         }
 725         printf("\n\n");
 726         return EXIT_SUCCESS;
 727 }
 728
 729 /* built-in 'jobs' handler */
 730 static int builtin_jobs(struct child_prog *child)
 731 {
 732         struct pipe *job;
 733         char *status_string;
 734
 735         for (job = job_list; job; job = job->next) {
 736                 if (job->running_progs == job->stopped_progs)
 737                         status_string = "Stopped";
 738                 else
 739                         status_string = "Running";
 740
 741                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 742         }
 743         return EXIT_SUCCESS;
 744 }
 745
 746
 747 /* built-in 'pwd' handler */
 748 static int builtin_pwd(struct child_prog *dummy)
 749 {
 750         puts(set_cwd());
 751         return EXIT_SUCCESS;
 752 }
 753
 754 /* built-in 'read VAR' handler */
 755 static int builtin_read(struct child_prog *child)
 756 {
 757         int res;
 758
 759         if (child->argv[1]) {
 760                 char string[BUFSIZ];
 761                 char *var = 0;
 762
 763                 string[0] = 0;  /* In case stdin has only EOF */
 764                 /* read string */
 765                 fgets(string, sizeof(string), stdin);
 766                 chomp(string);
 767                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 768                 if(var) {
 769                         sprintf(var, "%s=%s", child->argv[1], string);
 770                         res = set_local_var(var, 0);
 771                 } else
 772                         res = -1;
 773                 if (res)
 774                         fprintf(stderr, "read: %m\n");
 775                 free(var);      /* So not move up to avoid breaking errno */
 776                 return res;
 777         } else {
 778                 do res=getchar(); while(res!='\n' && res!=EOF);
 779                 return 0;
 780         }
 781 }
 782
 783 /* built-in 'set VAR=value' handler */
 784 static int builtin_set(struct child_prog *child)
 785 {
 786         char *temp = child->argv[1];
 787         struct variables *e;
 788
 789         if (temp == NULL)
 790                 for(e = top_vars; e; e=e->next)
 791                         printf("%s=%s\n", e->name, e->value);
 792         else
 793                 set_local_var(temp, 0);
 794
 795                 return EXIT_SUCCESS;
 796 }
 797
 798
 799 /* Built-in 'shift' handler */
 800 static int builtin_shift(struct child_prog *child)
 801 {
 802         int n=1;
 803         if (child->argv[1]) {
 804                 n=atoi(child->argv[1]);
 805         }
 806         if (n>=0 && n<global_argc) {
 807                 /* XXX This probably breaks $0 */
 808                 global_argc -= n;
 809                 global_argv += n;
 810                 return EXIT_SUCCESS;
 811         } else {
 812                 return EXIT_FAILURE;
 813         }
 814 }
 815
 816 /* Built-in '.' handler (read-in and execute commands from file) */
 817 static int builtin_source(struct child_prog *child)
 818 {
 819         FILE *input;
 820         int status;
 821
 822         if (child->argv[1] == NULL)
 823                 return EXIT_FAILURE;
 824
 825         /* XXX search through $PATH is missing */
 826         input = fopen(child->argv[1], "r");
 827         if (!input) {
 828                 error_msg("Couldn't open file '%s'", child->argv[1]);
 829                 return EXIT_FAILURE;
 830         }
 831
 832         /* Now run the file */
 833         /* XXX argv and argc are broken; need to save old global_argv
 834          * (pointer only is OK!) on this stack frame,
 835          * set global_argv=child->argv+1, recurse, and restore. */
 836         mark_open(fileno(input));
 837         status = parse_file_outer(input);
 838         mark_closed(fileno(input));
 839         fclose(input);
 840         return (status);
 841 }
 842
 843 static int builtin_umask(struct child_prog *child)
 844 {
 845         mode_t new_umask;
 846         const char *arg = child->argv[1];
 847         char *end;
 848         if (arg) {
 849                 new_umask=strtoul(arg, &end, 8);
 850                 if (*end!='\0' || end == arg) {
 851                         return EXIT_FAILURE;
 852                 }
 853         } else {
 854                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 855         }
 856         umask(new_umask);
 857         return EXIT_SUCCESS;
 858 }
 859
 860 /* built-in 'unset VAR' handler */
 861 static int builtin_unset(struct child_prog *child)
 862 {
 863         /* bash returned already true */
 864         unset_local_var(child->argv[1]);
 865         return EXIT_SUCCESS;
 866 }
 867
 868 static int builtin_not_written(struct child_prog *child)
 869 {
 870         printf("builtin_%s not written\n",child->argv[0]);
 871         return EXIT_FAILURE;
 872 }
 873 #endif
 874
 875 static int b_check_space(o_string *o, int len)
 876 {
 877         /* It would be easy to drop a more restrictive policy
 878          * in here, such as setting a maximum string length */
 879         if (o->length + len > o->maxlen) {
 880                 char *old_data = o->data;
 881                 /* assert (data == NULL || o->maxlen != 0); */
 882                 o->maxlen += max(2*len, B_CHUNK);
 883                 o->data = realloc(o->data, 1 + o->maxlen);
 884                 if (o->data == NULL) {
 885                         free(old_data);
 886                 }
 887         }
 888         return o->data == NULL;
 889 }
 890
 891 static int b_addchr(o_string *o, int ch)
 892 {
 893         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 894         if (b_check_space(o, 1)) return B_NOSPAC;
 895         o->data[o->length] = ch;
 896         o->length++;
 897         o->data[o->length] = '\0';
 898         return 0;
 899 }
 900
 901 static void b_reset(o_string *o)
 902 {
 903         o->length = 0;
 904         o->nonnull = 0;
 905         if (o->data != NULL) *o->data = '\0';
 906 }
 907
 908 static void b_free(o_string *o)
 909 {
 910         b_reset(o);
 911         free(o->data);
 912         o->data = NULL;
 913         o->maxlen = 0;
 914 }
 915
 916 /* My analysis of quoting semantics tells me that state information
 917  * is associated with a destination, not a source.
 918  */
 919 static int b_addqchr(o_string *o, int ch, int quote)
 920 {
 921         if (quote && strchr("*?[\\",ch)) {
 922                 int rc;
 923                 rc = b_addchr(o, '\\');
 924                 if (rc) return rc;
 925         }
 926         return b_addchr(o, ch);
 927 }
 928
 929 /* belongs in utility.c */
 930 char *simple_itoa(unsigned int i)
 931 {
 932         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 933         static char local[22];
 934         char *p = &local[21];
 935         *p-- = '\0';
 936         do {
 937                 *p-- = '0' + i % 10;
 938                 i /= 10;
 939         } while (i > 0);
 940         return p + 1;
 941 }
 942
 943 #ifndef __U_BOOT__
 944 static int b_adduint(o_string *o, unsigned int i)
 945 {
 946         int r;
 947         char *p = simple_itoa(i);
 948         /* no escape checking necessary */
 949         do r=b_addchr(o, *p++); while (r==0 && *p);
 950         return r;
 951 }
 952 #endif
 953
 954 static int static_get(struct in_str *i)
 955 {
 956         int ch=*i->p++;
 957         if (ch=='\0') return EOF;
 958         return ch;
 959 }
 960
 961 static int static_peek(struct in_str *i)
 962 {
 963         return *i->p;
 964 }
 965
 966 #ifndef __U_BOOT__
 967 static inline void cmdedit_set_initial_prompt(void)
 968 {
 969 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 970         PS1 = NULL;
 971 #else
 972         PS1 = getenv("PS1");
 973         if(PS1==0)
 974                 PS1 = "\\w \\$ ";
 975 #endif
 976 }
 977
 978 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 979 {
 980         debug_printf("setup_prompt_string %d ",promptmode);
 981 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 982         /* Set up the prompt */
 983         if (promptmode == 1) {
 984                 free(PS1);
 985                 PS1=xmalloc(strlen(cwd)+4);
 986                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 987                 *prompt_str = PS1;
 988         } else {
 989                 *prompt_str = PS2;
 990         }
 991 #else
 992         *prompt_str = (promptmode==1)? PS1 : PS2;
 993 #endif
 994         debug_printf("result %s\n",*prompt_str);
 995 }
 996 #endif
 997
 998 static void get_user_input(struct in_str *i)
 999 {
1000 #ifndef __U_BOOT__
1001         char *prompt_str;
1002         static char the_command[BUFSIZ];
1003
1004         setup_prompt_string(i->promptmode, &prompt_str);
1005 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1006         /*
1007          ** enable command line editing only while a command line
1008          ** is actually being read; otherwise, we'll end up bequeathing
1009          ** atexit() handlers and other unwanted stuff to our
1010          ** child processes (rob@sysgo.de)
1011          */
1012         cmdedit_read_input(prompt_str, the_command);
1013 #else
1014         fputs(prompt_str, stdout);
1015         fflush(stdout);
1016         the_command[0]=fgetc(i->file);
1017         the_command[1]='\0';
1018 #endif
1019         fflush(stdout);
1020         i->p = the_command;
1021 #else
1022         extern char console_buffer[CFG_CBSIZE];
1023         int n;
1024         static char the_command[CFG_CBSIZE];
1025
1026 #ifdef CONFIG_BOOT_RETRY_TIME
1027 #  ifdef CONFIG_RESET_TO_RETRY
1028         extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1029 #  else
1030 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1031 #  endif
1032         reset_cmd_timeout();
1033 #endif
1034         i->__promptme = 1;
1035         if (i->promptmode == 1) {
1036                 n = readline(CFG_PROMPT);
1037         } else {
1038                 n = readline(CFG_PROMPT_HUSH_PS2);
1039         }
1040 #ifdef CONFIG_BOOT_RETRY_TIME
1041         if (n == -2) {
1042           puts("\nTimeout waiting for command\n");
1043 #  ifdef CONFIG_RESET_TO_RETRY
1044           do_reset(NULL, 0, 0, NULL);
1045 #  else
1046 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1047 #  endif
1048         }
1049 #endif
1050         if (n == -1 ) {
1051                 flag_repeat = 0;
1052                 i->__promptme = 0;
1053         }
1054         n = strlen(console_buffer);
1055         console_buffer[n] = '\n';
1056         console_buffer[n+1]= '\0';
1057         if (had_ctrlc()) flag_repeat = 0;
1058         clear_ctrlc();
1059         do_repeat = 0;
1060         if (i->promptmode == 1) {
1061                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1062                         strcpy(the_command,console_buffer);
1063                 }
1064                 else {
1065                         if (console_buffer[0] != '\n') {
1066                                 strcpy(the_command,console_buffer);
1067                                 flag_repeat = 1;
1068                         }
1069                         else {
1070                                 do_repeat = 1;
1071                         }
1072                 }
1073                 i->p = the_command;
1074         }
1075         else {
1076                 if (console_buffer[0] != '\n') {
1077                         if (strlen(the_command) + strlen(console_buffer)
1078                             < CFG_CBSIZE) {
1079                                 n = strlen(the_command);
1080                                 the_command[n-1] = ' ';
1081                                 strcpy(&the_command[n],console_buffer);
1082                         }
1083                         else {
1084                                 the_command[0] = '\n';
1085                                 the_command[1] = '\0';
1086                                 flag_repeat = 0;
1087                         }
1088                 }
1089                 if (i->__promptme == 0) {
1090                         the_command[0] = '\n';
1091                         the_command[1] = '\0';
1092                 }
1093                 i->p = console_buffer;
1094         }
1095 #endif
1096 }
1097
1098 /* This is the magic location that prints prompts
1099  * and gets data back from the user */
1100 static int file_get(struct in_str *i)
1101 {
1102         int ch;
1103
1104         ch = 0;
1105         /* If there is data waiting, eat it up */
1106         if (i->p && *i->p) {
1107                 ch=*i->p++;
1108         } else {
1109                 /* need to double check i->file because we might be doing something
1110                  * more complicated by now, like sourcing or substituting. */
1111 #ifndef __U_BOOT__
1112                 if (i->__promptme && interactive && i->file == stdin) {
1113                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1114 #else
1115                         while(! i->p  || strlen(i->p)==0 ) {
1116 #endif
1117                                 get_user_input(i);
1118                         }
1119                         i->promptmode=2;
1120 #ifndef __U_BOOT__
1121                         i->__promptme = 0;
1122 #endif
1123                         if (i->p && *i->p) {
1124                                 ch=*i->p++;
1125                         }
1126 #ifndef __U_BOOT__
1127                 } else {
1128                         ch = fgetc(i->file);
1129                 }
1130
1131 #endif
1132                 debug_printf("b_getch: got a %d\n", ch);
1133         }
1134 #ifndef __U_BOOT__
1135         if (ch == '\n') i->__promptme=1;
1136 #endif
1137         return ch;
1138 }
1139
1140 /* All the callers guarantee this routine will never be
1141  * used right after a newline, so prompting is not needed.
1142  */
1143 static int file_peek(struct in_str *i)
1144 {
1145 #ifndef __U_BOOT__
1146         if (i->p && *i->p) {
1147 #endif
1148                 return *i->p;
1149 #ifndef __U_BOOT__
1150         } else {
1151                 i->peek_buf[0] = fgetc(i->file);
1152                 i->peek_buf[1] = '\0';
1153                 i->p = i->peek_buf;
1154                 debug_printf("b_peek: got a %d\n", *i->p);
1155                 return *i->p;
1156         }
1157 #endif
1158 }
1159
1160 #ifndef __U_BOOT__
1161 static void setup_file_in_str(struct in_str *i, FILE *f)
1162 #else
1163 static void setup_file_in_str(struct in_str *i)
1164 #endif
1165 {
1166         i->peek = file_peek;
1167         i->get = file_get;
1168         i->__promptme=1;
1169         i->promptmode=1;
1170 #ifndef __U_BOOT__
1171         i->file = f;
1172 #endif
1173         i->p = NULL;
1174 }
1175
1176 static void setup_string_in_str(struct in_str *i, const char *s)
1177 {
1178         i->peek = static_peek;
1179         i->get = static_get;
1180         i->__promptme=1;
1181         i->promptmode=1;
1182         i->p = s;
1183 }
1184
1185 #ifndef __U_BOOT__
1186 static void mark_open(int fd)
1187 {
1188         struct close_me *new = xmalloc(sizeof(struct close_me));
1189         new->fd = fd;
1190         new->next = close_me_head;
1191         close_me_head = new;
1192 }
1193
1194 static void mark_closed(int fd)
1195 {
1196         struct close_me *tmp;
1197         if (close_me_head == NULL || close_me_head->fd != fd)
1198                 error_msg_and_die("corrupt close_me");
1199         tmp = close_me_head;
1200         close_me_head = close_me_head->next;
1201         free(tmp);
1202 }
1203
1204 static void close_all(void)
1205 {
1206         struct close_me *c;
1207         for (c=close_me_head; c; c=c->next) {
1208                 close(c->fd);
1209         }
1210         close_me_head = NULL;
1211 }
1212
1213 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1214  * and stderr if they are redirected. */
1215 static int setup_redirects(struct child_prog *prog, int squirrel[])
1216 {
1217         int openfd, mode;
1218         struct redir_struct *redir;
1219
1220         for (redir=prog->redirects; redir; redir=redir->next) {
1221                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1222                         /* something went wrong in the parse.  Pretend it didn't happen */
1223                         continue;
1224                 }
1225                 if (redir->dup == -1) {
1226                         mode=redir_table[redir->type].mode;
1227                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1228                         if (openfd < 0) {
1229                         /* this could get lost if stderr has been redirected, but
1230                            bash and ash both lose it as well (though zsh doesn't!) */
1231                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1232                                 return 1;
1233                         }
1234                 } else {
1235                         openfd = redir->dup;
1236                 }
1237
1238                 if (openfd != redir->fd) {
1239                         if (squirrel && redir->fd < 3) {
1240                                 squirrel[redir->fd] = dup(redir->fd);
1241                         }
1242                         if (openfd == -3) {
1243                                 close(openfd);
1244                         } else {
1245                                 dup2(openfd, redir->fd);
1246                                 if (redir->dup == -1)
1247                                         close (openfd);
1248                         }
1249                 }
1250         }
1251         return 0;
1252 }
1253
1254 static void restore_redirects(int squirrel[])
1255 {
1256         int i, fd;
1257         for (i=0; i<3; i++) {
1258                 fd = squirrel[i];
1259                 if (fd != -1) {
1260                         /* No error checking.  I sure wouldn't know what
1261                          * to do with an error if I found one! */
1262                         dup2(fd, i);
1263                         close(fd);
1264                 }
1265         }
1266 }
1267
1268 /* never returns */
1269 /* XXX no exit() here.  If you don't exec, use _exit instead.
1270  * The at_exit handlers apparently confuse the calling process,
1271  * in particular stdin handling.  Not sure why? */
1272 static void pseudo_exec(struct child_prog *child)
1273 {
1274         int i, rcode;
1275         char *p;
1276         struct built_in_command *x;
1277         if (child->argv) {
1278                 for (i=0; is_assignment(child->argv[i]); i++) {
1279                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1280                         p = insert_var_value(child->argv[i]);
1281                         putenv(strdup(p));
1282                         if (p != child->argv[i]) free(p);
1283                 }
1284                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1285                                         to exit, and therefore don't need to keep data
1286                                         structures consistent for free() use. */
1287                 /* If a variable is assigned in a forest, and nobody listens,
1288                  * was it ever really set?
1289                  */
1290                 if (child->argv[0] == NULL) {
1291                         _exit(EXIT_SUCCESS);
1292                 }
1293
1294                 /*
1295                  * Check if the command matches any of the builtins.
1296                  * Depending on context, this might be redundant.  But it's
1297                  * easier to waste a few CPU cycles than it is to figure out
1298                  * if this is one of those cases.
1299                  */
1300                 for (x = bltins; x->cmd; x++) {
1301                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1302                                 debug_printf("builtin exec %s\n", child->argv[0]);
1303                                 rcode = x->function(child);
1304                                 fflush(stdout);
1305                                 _exit(rcode);
1306                         }
1307                 }
1308
1309                 /* Check if the command matches any busybox internal commands
1310                  * ("applets") here.
1311                  * FIXME: This feature is not 100% safe, since
1312                  * BusyBox is not fully reentrant, so we have no guarantee the things
1313                  * from the .bss are still zeroed, or that things from .data are still
1314                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1315                  * really dislike relying on /proc for things.  We could exec ourself
1316                  * from global_argv[0], but if we are in a chroot, we may not be able
1317                  * to find ourself... */
1318 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1319                 {
1320                         int argc_l;
1321                         char** argv_l=child->argv;
1322                         char *name = child->argv[0];
1323
1324 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1325                         /* Following discussions from November 2000 on the busybox mailing
1326                          * list, the default configuration, (without
1327                          * get_last_path_component()) lets the user force use of an
1328                          * external command by specifying the full (with slashes) filename.
1329                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1330                          * _aways_ override external commands, so if you want to run
1331                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1332                          * filesystem and is _not_ busybox.  Some systems may want this,
1333                          * most do not.  */
1334                         name = get_last_path_component(name);
1335 #endif
1336                         /* Count argc for use in a second... */
1337                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1338                         optind = 1;
1339                         debug_printf("running applet %s\n", name);
1340                         run_applet_by_name(name, argc_l, child->argv);
1341                 }
1342 #endif
1343                 debug_printf("exec of %s\n",child->argv[0]);
1344                 execvp(child->argv[0],child->argv);
1345                 perror_msg("couldn't exec: %s",child->argv[0]);
1346                 _exit(1);
1347         } else if (child->group) {
1348                 debug_printf("runtime nesting to group\n");
1349                 interactive=0;    /* crucial!!!! */
1350                 rcode = run_list_real(child->group);
1351                 /* OK to leak memory by not calling free_pipe_list,
1352                  * since this process is about to exit */
1353                 _exit(rcode);
1354         } else {
1355                 /* Can happen.  See what bash does with ">foo" by itself. */
1356                 debug_printf("trying to pseudo_exec null command\n");
1357                 _exit(EXIT_SUCCESS);
1358         }
1359 }
1360
1361 static void insert_bg_job(struct pipe *pi)
1362 {
1363         struct pipe *thejob;
1364
1365         /* Linear search for the ID of the job to use */
1366         pi->jobid = 1;
1367         for (thejob = job_list; thejob; thejob = thejob->next)
1368                 if (thejob->jobid >= pi->jobid)
1369                         pi->jobid = thejob->jobid + 1;
1370
1371         /* add thejob to the list of running jobs */
1372         if (!job_list) {
1373                 thejob = job_list = xmalloc(sizeof(*thejob));
1374         } else {
1375                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1376                 thejob->next = xmalloc(sizeof(*thejob));
1377                 thejob = thejob->next;
1378         }
1379
1380         /* physically copy the struct job */
1381         memcpy(thejob, pi, sizeof(struct pipe));
1382         thejob->next = NULL;
1383         thejob->running_progs = thejob->num_progs;
1384         thejob->stopped_progs = 0;
1385         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1386
1387         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1388         {
1389                 char *bar=thejob->text;
1390                 char **foo=pi->progs[0].argv;
1391                 while(foo && *foo) {
1392                         bar += sprintf(bar, "%s ", *foo++);
1393                 }
1394         }
1395
1396         /* we don't wait for background thejobs to return -- append it
1397            to the list of backgrounded thejobs and leave it alone */
1398         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1399         last_bg_pid = thejob->progs[0].pid;
1400         last_jobid = thejob->jobid;
1401 }
1402
1403 /* remove a backgrounded job */
1404 static void remove_bg_job(struct pipe *pi)
1405 {
1406         struct pipe *prev_pipe;
1407
1408         if (pi == job_list) {
1409                 job_list = pi->next;
1410         } else {
1411                 prev_pipe = job_list;
1412                 while (prev_pipe->next != pi)
1413                         prev_pipe = prev_pipe->next;
1414                 prev_pipe->next = pi->next;
1415         }
1416         if (job_list)
1417                 last_jobid = job_list->jobid;
1418         else
1419                 last_jobid = 0;
1420
1421         pi->stopped_progs = 0;
1422         free_pipe(pi, 0);
1423         free(pi);
1424 }
1425
1426 /* Checks to see if any processes have exited -- if they
1427    have, figure out why and see if a job has completed */
1428 static int checkjobs(struct pipe* fg_pipe)
1429 {
1430         int attributes;
1431         int status;
1432         int prognum = 0;
1433         struct pipe *pi;
1434         pid_t childpid;
1435
1436         attributes = WUNTRACED;
1437         if (fg_pipe==NULL) {
1438                 attributes |= WNOHANG;
1439         }
1440
1441         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1442                 if (fg_pipe) {
1443                         int i, rcode = 0;
1444                         for (i=0; i < fg_pipe->num_progs; i++) {
1445                                 if (fg_pipe->progs[i].pid == childpid) {
1446                                         if (i==fg_pipe->num_progs-1)
1447                                                 rcode=WEXITSTATUS(status);
1448                                         (fg_pipe->num_progs)--;
1449                                         return(rcode);
1450                                 }
1451                         }
1452                 }
1453
1454                 for (pi = job_list; pi; pi = pi->next) {
1455                         prognum = 0;
1456                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1457                                 prognum++;
1458                         }
1459                         if (prognum < pi->num_progs)
1460                                 break;
1461                 }
1462
1463                 if(pi==NULL) {
1464                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1465                         continue;
1466                 }
1467
1468                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1469                         /* child exited */
1470                         pi->running_progs--;
1471                         pi->progs[prognum].pid = 0;
1472
1473                         if (!pi->running_progs) {
1474                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1475                                 remove_bg_job(pi);
1476                         }
1477                 } else {
1478                         /* child stopped */
1479                         pi->stopped_progs++;
1480                         pi->progs[prognum].is_stopped = 1;
1481
1482 #if 0
1483                         /* Printing this stuff is a pain, since it tends to
1484                          * overwrite the prompt an inconveinient moments.  So
1485                          * don't do that.  */
1486                         if (pi->stopped_progs == pi->num_progs) {
1487                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1488                         }
1489 #endif
1490                 }
1491         }
1492
1493         if (childpid == -1 && errno != ECHILD)
1494                 perror_msg("waitpid");
1495
1496         /* move the shell to the foreground */
1497         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1498         /*      perror_msg("tcsetpgrp-2"); */
1499         return -1;
1500 }
1501
1502 /* Figure out our controlling tty, checking in order stderr,
1503  * stdin, and stdout.  If check_pgrp is set, also check that
1504  * we belong to the foreground process group associated with
1505  * that tty.  The value of shell_terminal is needed in order to call
1506  * tcsetpgrp(shell_terminal, ...); */
1507 void controlling_tty(int check_pgrp)
1508 {
1509         pid_t curpgrp;
1510
1511         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1512                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1513                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1514                 goto shell_terminal_error;
1515
1516         if (check_pgrp && curpgrp != getpgid(0))
1517                 goto shell_terminal_error;
1518
1519         return;
1520
1521 shell_terminal_error:
1522                 shell_terminal = -1;
1523                 return;
1524 }
1525 #endif
1526
1527 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1528  * to finish.  See checkjobs().
1529  *
1530  * return code is normally -1, when the caller has to wait for children
1531  * to finish to determine the exit status of the pipe.  If the pipe
1532  * is a simple builtin command, however, the action is done by the
1533  * time run_pipe_real returns, and the exit code is provided as the
1534  * return value.
1535  *
1536  * The input of the pipe is always stdin, the output is always
1537  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1538  * because it tries to avoid running the command substitution in
1539  * subshell, when that is in fact necessary.  The subshell process
1540  * now has its stdout directed to the input of the appropriate pipe,
1541  * so this routine is noticeably simpler.
1542  */
1543 static int run_pipe_real(struct pipe *pi)
1544 {
1545         int i;
1546 #ifndef __U_BOOT__
1547         int nextin, nextout;
1548         int pipefds[2];                         /* pipefds[0] is for reading */
1549         struct child_prog *child;
1550         struct built_in_command *x;
1551         char *p;
1552 # if __GNUC__
1553         /* Avoid longjmp clobbering */
1554         (void) &i;
1555         (void) &nextin;
1556         (void) &nextout;
1557         (void) &child;
1558 # endif
1559 #else
1560         int nextin;
1561         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1562         struct child_prog *child;
1563         cmd_tbl_t *cmdtp;
1564         char *p;
1565 # if __GNUC__
1566         /* Avoid longjmp clobbering */
1567         (void) &i;
1568         (void) &nextin;
1569         (void) &child;
1570 # endif
1571 #endif  /* __U_BOOT__ */
1572
1573         nextin = 0;
1574 #ifndef __U_BOOT__
1575         pi->pgrp = -1;
1576 #endif
1577
1578         /* Check if this is a simple builtin (not part of a pipe).
1579          * Builtins within pipes have to fork anyway, and are handled in
1580          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1581          */
1582         if (pi->num_progs == 1) child = & (pi->progs[0]);
1583 #ifndef __U_BOOT__
1584         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1585                 int squirrel[] = {-1, -1, -1};
1586                 int rcode;
1587                 debug_printf("non-subshell grouping\n");
1588                 setup_redirects(child, squirrel);
1589                 /* XXX could we merge code with following builtin case,
1590                  * by creating a pseudo builtin that calls run_list_real? */
1591                 rcode = run_list_real(child->group);
1592                 restore_redirects(squirrel);
1593 #else
1594                 if (pi->num_progs == 1 && child->group) {
1595                 int rcode;
1596                 debug_printf("non-subshell grouping\n");
1597                 rcode = run_list_real(child->group);
1598 #endif
1599                 return rcode;
1600         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1601                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1602                 if (i!=0 && child->argv[i]==NULL) {
1603                         /* assignments, but no command: set the local environment */
1604                         for (i=0; child->argv[i]!=NULL; i++) {
1605
1606                                 /* Ok, this case is tricky.  We have to decide if this is a
1607                                  * local variable, or an already exported variable.  If it is
1608                                  * already exported, we have to export the new value.  If it is
1609                                  * not exported, we need only set this as a local variable.
1610                                  * This junk is all to decide whether or not to export this
1611                                  * variable. */
1612                                 int export_me=0;
1613                                 char *name, *value;
1614                                 name = xstrdup(child->argv[i]);
1615                                 debug_printf("Local environment set: %s\n", name);
1616                                 value = strchr(name, '=');
1617                                 if (value)
1618                                         *value=0;
1619 #ifndef __U_BOOT__
1620                                 if ( get_local_var(name)) {
1621                                         export_me=1;
1622                                 }
1623 #endif
1624                                 free(name);
1625                                 p = insert_var_value(child->argv[i]);
1626                                 set_local_var(p, export_me);
1627                                 if (p != child->argv[i]) free(p);
1628                         }
1629                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1630                 }
1631                 for (i = 0; is_assignment(child->argv[i]); i++) {
1632                         p = insert_var_value(child->argv[i]);
1633 #ifndef __U_BOOT__
1634                         putenv(strdup(p));
1635 #else
1636                         set_local_var(p, 0);
1637 #endif
1638                         if (p != child->argv[i]) {
1639                                 child->sp--;
1640                                 free(p);
1641                         }
1642                 }
1643                 if (child->sp) {
1644                         char * str = NULL;
1645
1646                         str = make_string((child->argv + i));
1647                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1648                         free(str);
1649                         return last_return_code;
1650                 }
1651 #ifndef __U_BOOT__
1652                 for (x = bltins; x->cmd; x++) {
1653                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1654                                 int squirrel[] = {-1, -1, -1};
1655                                 int rcode;
1656                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1657                                         debug_printf("magic exec\n");
1658                                         setup_redirects(child,NULL);
1659                                         return EXIT_SUCCESS;
1660                                 }
1661                                 debug_printf("builtin inline %s\n", child->argv[0]);
1662                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1663                                  * This is perfect for work that comes after exec().
1664                                  * Is it really safe for inline use?  Experimentally,
1665                                  * things seem to work with glibc. */
1666                                 setup_redirects(child, squirrel);
1667 #else
1668                         /* check ";", because ,example , argv consist from
1669                          * "help;flinfo" must not execute
1670                          */
1671                         if (strchr(child->argv[i], ';')) {
1672                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1673                                         child->argv[i]);
1674                                 return -1;
1675                         }
1676                         /* Look up command in command table */
1677
1678
1679                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1680                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1681                                 return -1;      /* give up after bad command */
1682                         } else {
1683                                 int rcode;
1684 #if defined(CONFIG_CMD_BOOTD)
1685             extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1686
1687                                 /* avoid "bootd" recursion */
1688                                 if (cmdtp->cmd == do_bootd) {
1689                                         if (flag & CMD_FLAG_BOOTD) {
1690                                                 printf ("'bootd' recursion detected\n");
1691                                                 return -1;
1692                                         }
1693                                 else
1694                                         flag |= CMD_FLAG_BOOTD;
1695                                 }
1696 #endif
1697                                 /* found - check max args */
1698                                 if ((child->argc - i) > cmdtp->maxargs) {
1699                                         printf ("Usage:\n%s\n", cmdtp->usage);
1700                                         return -1;
1701                                 }
1702 #endif
1703                                 child->argv+=i;  /* XXX horrible hack */
1704 #ifndef __U_BOOT__
1705                                 rcode = x->function(child);
1706 #else
1707                                 /* OK - call function to do the command */
1708
1709                                 rcode = (cmdtp->cmd)
1710 (cmdtp, flag,child->argc-i,&child->argv[i]);
1711                                 if ( !cmdtp->repeatable )
1712                                         flag_repeat = 0;
1713
1714
1715 #endif
1716                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1717 #ifndef __U_BOOT__
1718
1719                                 restore_redirects(squirrel);
1720 #endif
1721
1722                                 return rcode;
1723                         }
1724                 }
1725 #ifndef __U_BOOT__
1726         }
1727
1728         for (i = 0; i < pi->num_progs; i++) {
1729                 child = & (pi->progs[i]);
1730
1731                 /* pipes are inserted between pairs of commands */
1732                 if ((i + 1) < pi->num_progs) {
1733                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1734                         nextout = pipefds[1];
1735                 } else {
1736                         nextout=1;
1737                         pipefds[0] = -1;
1738                 }
1739
1740                 /* XXX test for failed fork()? */
1741                 if (!(child->pid = fork())) {
1742                         /* Set the handling for job control signals back to the default.  */
1743                         signal(SIGINT, SIG_DFL);
1744                         signal(SIGQUIT, SIG_DFL);
1745                         signal(SIGTERM, SIG_DFL);
1746                         signal(SIGTSTP, SIG_DFL);
1747                         signal(SIGTTIN, SIG_DFL);
1748                         signal(SIGTTOU, SIG_DFL);
1749                         signal(SIGCHLD, SIG_DFL);
1750
1751                         close_all();
1752
1753                         if (nextin != 0) {
1754                                 dup2(nextin, 0);
1755                                 close(nextin);
1756                         }
1757                         if (nextout != 1) {
1758                                 dup2(nextout, 1);
1759                                 close(nextout);
1760                         }
1761                         if (pipefds[0]!=-1) {
1762                                 close(pipefds[0]);  /* opposite end of our output pipe */
1763                         }
1764
1765                         /* Like bash, explicit redirects override pipes,
1766                          * and the pipe fd is available for dup'ing. */
1767                         setup_redirects(child,NULL);
1768
1769                         if (interactive && pi->followup!=PIPE_BG) {
1770                                 /* If we (the child) win the race, put ourselves in the process
1771                                  * group whose leader is the first process in this pipe. */
1772                                 if (pi->pgrp < 0) {
1773                                         pi->pgrp = getpid();
1774                                 }
1775                                 if (setpgid(0, pi->pgrp) == 0) {
1776                                         tcsetpgrp(2, pi->pgrp);
1777                                 }
1778                         }
1779
1780                         pseudo_exec(child);
1781                 }
1782
1783
1784                 /* put our child in the process group whose leader is the
1785                    first process in this pipe */
1786                 if (pi->pgrp < 0) {
1787                         pi->pgrp = child->pid;
1788                 }
1789                 /* Don't check for errors.  The child may be dead already,
1790                  * in which case setpgid returns error code EACCES. */
1791                 setpgid(child->pid, pi->pgrp);
1792
1793                 if (nextin != 0)
1794                         close(nextin);
1795                 if (nextout != 1)
1796                         close(nextout);
1797
1798                 /* If there isn't another process, nextin is garbage
1799                    but it doesn't matter */
1800                 nextin = pipefds[0];
1801         }
1802 #endif
1803         return -1;
1804 }
1805
1806 static int run_list_real(struct pipe *pi)
1807 {
1808         char *save_name = NULL;
1809         char **list = NULL;
1810         char **save_list = NULL;
1811         struct pipe *rpipe;
1812         int flag_rep = 0;
1813 #ifndef __U_BOOT__
1814         int save_num_progs;
1815 #endif
1816         int rcode=0, flag_skip=1;
1817         int flag_restore = 0;
1818         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1819         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1820         /* check syntax for "for" */
1821         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1822                 if ((rpipe->r_mode == RES_IN ||
1823                     rpipe->r_mode == RES_FOR) &&
1824                     (rpipe->next == NULL)) {
1825                                 syntax();
1826 #ifdef __U_BOOT__
1827                                 flag_repeat = 0;
1828 #endif
1829                                 return 1;
1830                 }
1831                 if ((rpipe->r_mode == RES_IN &&
1832                         (rpipe->next->r_mode == RES_IN &&
1833                         rpipe->next->progs->argv != NULL))||
1834                         (rpipe->r_mode == RES_FOR &&
1835                         rpipe->next->r_mode != RES_IN)) {
1836                                 syntax();
1837 #ifdef __U_BOOT__
1838                                 flag_repeat = 0;
1839 #endif
1840                                 return 1;
1841                 }
1842         }
1843         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1844                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1845                         pi->r_mode == RES_FOR) {
1846 #ifdef __U_BOOT__
1847                                 /* check Ctrl-C */
1848                                 ctrlc();
1849                                 if ((had_ctrlc())) {
1850                                         return 1;
1851                                 }
1852 #endif
1853                                 flag_restore = 0;
1854                                 if (!rpipe) {
1855                                         flag_rep = 0;
1856                                         rpipe = pi;
1857                                 }
1858                 }
1859                 rmode = pi->r_mode;
1860                 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);
1861                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1862                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1863                         continue;
1864                 }
1865                 flag_skip = 1;
1866                 skip_more_in_this_rmode = RES_XXXX;
1867                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1868                 if (rmode == RES_THEN &&  if_code) continue;
1869                 if (rmode == RES_ELSE && !if_code) continue;
1870                 if (rmode == RES_ELIF && !if_code) break;
1871                 if (rmode == RES_FOR && pi->num_progs) {
1872                         if (!list) {
1873                                 /* if no variable values after "in" we skip "for" */
1874                                 if (!pi->next->progs->argv) continue;
1875                                 /* create list of variable values */
1876                                 list = make_list_in(pi->next->progs->argv,
1877                                         pi->progs->argv[0]);
1878                                 save_list = list;
1879                                 save_name = pi->progs->argv[0];
1880                                 pi->progs->argv[0] = NULL;
1881                                 flag_rep = 1;
1882                         }
1883                         if (!(*list)) {
1884                                 free(pi->progs->argv[0]);
1885                                 free(save_list);
1886                                 list = NULL;
1887                                 flag_rep = 0;
1888                                 pi->progs->argv[0] = save_name;
1889 #ifndef __U_BOOT__
1890                                 pi->progs->glob_result.gl_pathv[0] =
1891                                         pi->progs->argv[0];
1892 #endif
1893                                 continue;
1894                         } else {
1895                                 /* insert new value from list for variable */
1896                                 if (pi->progs->argv[0])
1897                                         free(pi->progs->argv[0]);
1898                                 pi->progs->argv[0] = *list++;
1899 #ifndef __U_BOOT__
1900                                 pi->progs->glob_result.gl_pathv[0] =
1901                                         pi->progs->argv[0];
1902 #endif
1903                         }
1904                 }
1905                 if (rmode == RES_IN) continue;
1906                 if (rmode == RES_DO) {
1907                         if (!flag_rep) continue;
1908                 }
1909                 if ((rmode == RES_DONE)) {
1910                         if (flag_rep) {
1911                                 flag_restore = 1;
1912                         } else {
1913                                 rpipe = NULL;
1914                         }
1915                 }
1916                 if (pi->num_progs == 0) continue;
1917 #ifndef __U_BOOT__
1918                 save_num_progs = pi->num_progs; /* save number of programs */
1919 #endif
1920                 rcode = run_pipe_real(pi);
1921                 debug_printf("run_pipe_real returned %d\n",rcode);
1922 #ifndef __U_BOOT__
1923                 if (rcode!=-1) {
1924                         /* We only ran a builtin: rcode was set by the return value
1925                          * of run_pipe_real(), and we don't need to wait for anything. */
1926                 } else if (pi->followup==PIPE_BG) {
1927                         /* XXX check bash's behavior with nontrivial pipes */
1928                         /* XXX compute jobid */
1929                         /* XXX what does bash do with attempts to background builtins? */
1930                         insert_bg_job(pi);
1931                         rcode = EXIT_SUCCESS;
1932                 } else {
1933                         if (interactive) {
1934                                 /* move the new process group into the foreground */
1935                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1936                                         perror_msg("tcsetpgrp-3");
1937                                 rcode = checkjobs(pi);
1938                                 /* move the shell to the foreground */
1939                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1940                                         perror_msg("tcsetpgrp-4");
1941                         } else {
1942                                 rcode = checkjobs(pi);
1943                         }
1944                         debug_printf("checkjobs returned %d\n",rcode);
1945                 }
1946                 last_return_code=rcode;
1947 #else
1948                 if (rcode < -1) {
1949                         last_return_code = -rcode - 2;
1950                         return -2;      /* exit */
1951                 }
1952                 last_return_code=(rcode == 0) ? 0 : 1;
1953 #endif
1954 #ifndef __U_BOOT__
1955                 pi->num_progs = save_num_progs; /* restore number of programs */
1956 #endif
1957                 if ( rmode == RES_IF || rmode == RES_ELIF )
1958                         next_if_code=rcode;  /* can be overwritten a number of times */
1959                 if (rmode == RES_WHILE)
1960                         flag_rep = !last_return_code;
1961                 if (rmode == RES_UNTIL)
1962                         flag_rep = last_return_code;
1963                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1964                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1965                         skip_more_in_this_rmode=rmode;
1966 #ifndef __U_BOOT__
1967                 checkjobs(NULL);
1968 #endif
1969         }
1970         return rcode;
1971 }
1972
1973 /* broken, of course, but OK for testing */
1974 static char *indenter(int i)
1975 {
1976         static char blanks[]="                                    ";
1977         return &blanks[sizeof(blanks)-i-1];
1978 }
1979
1980 /* return code is the exit status of the pipe */
1981 static int free_pipe(struct pipe *pi, int indent)
1982 {
1983         char **p;
1984         struct child_prog *child;
1985 #ifndef __U_BOOT__
1986         struct redir_struct *r, *rnext;
1987 #endif
1988         int a, i, ret_code=0;
1989         char *ind = indenter(indent);
1990
1991 #ifndef __U_BOOT__
1992         if (pi->stopped_progs > 0)
1993                 return ret_code;
1994         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1995 #endif
1996         for (i=0; i<pi->num_progs; i++) {
1997                 child = &pi->progs[i];
1998                 final_printf("%s  command %d:\n",ind,i);
1999                 if (child->argv) {
2000                         for (a=0,p=child->argv; *p; a++,p++) {
2001                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
2002                         }
2003 #ifndef __U_BOOT__
2004                         globfree(&child->glob_result);
2005 #else
2006                         for (a = child->argc;a >= 0;a--) {
2007                                 free(child->argv[a]);
2008                         }
2009                                         free(child->argv);
2010                         child->argc = 0;
2011 #endif
2012                         child->argv=NULL;
2013                 } else if (child->group) {
2014 #ifndef __U_BOOT__
2015                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
2016 #endif
2017                         ret_code = free_pipe_list(child->group,indent+3);
2018                         final_printf("%s   end group\n",ind);
2019                 } else {
2020                         final_printf("%s   (nil)\n",ind);
2021                 }
2022 #ifndef __U_BOOT__
2023                 for (r=child->redirects; r; r=rnext) {
2024                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2025                         if (r->dup == -1) {
2026                                 /* guard against the case >$FOO, where foo is unset or blank */
2027                                 if (r->word.gl_pathv) {
2028                                         final_printf(" %s\n", *r->word.gl_pathv);
2029                                         globfree(&r->word);
2030                                 }
2031                         } else {
2032                                 final_printf("&%d\n", r->dup);
2033                         }
2034                         rnext=r->next;
2035                         free(r);
2036                 }
2037                 child->redirects=NULL;
2038 #endif
2039         }
2040         free(pi->progs);   /* children are an array, they get freed all at once */
2041         pi->progs=NULL;
2042         return ret_code;
2043 }
2044
2045 static int free_pipe_list(struct pipe *head, int indent)
2046 {
2047         int rcode=0;   /* if list has no members */
2048         struct pipe *pi, *next;
2049         char *ind = indenter(indent);
2050         for (pi=head; pi; pi=next) {
2051                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2052                 rcode = free_pipe(pi, indent);
2053                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2054                 next=pi->next;
2055                 pi->next=NULL;
2056                 free(pi);
2057         }
2058         return rcode;
2059 }
2060
2061 /* Select which version we will use */
2062 static int run_list(struct pipe *pi)
2063 {
2064         int rcode=0;
2065 #ifndef __U_BOOT__
2066         if (fake_mode==0) {
2067 #endif
2068                 rcode = run_list_real(pi);
2069 #ifndef __U_BOOT__
2070         }
2071 #endif
2072         /* free_pipe_list has the side effect of clearing memory
2073          * In the long run that function can be merged with run_list_real,
2074          * but doing that now would hobble the debugging effort. */
2075         free_pipe_list(pi,0);
2076         return rcode;
2077 }
2078
2079 /* The API for glob is arguably broken.  This routine pushes a non-matching
2080  * string into the output structure, removing non-backslashed backslashes.
2081  * If someone can prove me wrong, by performing this function within the
2082  * original glob(3) api, feel free to rewrite this routine into oblivion.
2083  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2084  * XXX broken if the last character is '\\', check that before calling.
2085  */
2086 #ifndef __U_BOOT__
2087 static int globhack(const char *src, int flags, glob_t *pglob)
2088 {
2089         int cnt=0, pathc;
2090         const char *s;
2091         char *dest;
2092         for (cnt=1, s=src; s && *s; s++) {
2093                 if (*s == '\\') s++;
2094                 cnt++;
2095         }
2096         dest = malloc(cnt);
2097         if (!dest) return GLOB_NOSPACE;
2098         if (!(flags & GLOB_APPEND)) {
2099                 pglob->gl_pathv=NULL;
2100                 pglob->gl_pathc=0;
2101                 pglob->gl_offs=0;
2102                 pglob->gl_offs=0;
2103         }
2104         pathc = ++pglob->gl_pathc;
2105         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2106         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2107         pglob->gl_pathv[pathc-1]=dest;
2108         pglob->gl_pathv[pathc]=NULL;
2109         for (s=src; s && *s; s++, dest++) {
2110                 if (*s == '\\') s++;
2111                 *dest = *s;
2112         }
2113         *dest='\0';
2114         return 0;
2115 }
2116
2117 /* XXX broken if the last character is '\\', check that before calling */
2118 static int glob_needed(const char *s)
2119 {
2120         for (; *s; s++) {
2121                 if (*s == '\\') s++;
2122                 if (strchr("*[?",*s)) return 1;
2123         }
2124         return 0;
2125 }
2126
2127 #if 0
2128 static void globprint(glob_t *pglob)
2129 {
2130         int i;
2131         debug_printf("glob_t at %p:\n", pglob);
2132         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2133                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2134         for (i=0; i<pglob->gl_pathc; i++)
2135                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2136                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2137 }
2138 #endif
2139
2140 static int xglob(o_string *dest, int flags, glob_t *pglob)
2141 {
2142         int gr;
2143
2144         /* short-circuit for null word */
2145         /* we can code this better when the debug_printf's are gone */
2146         if (dest->length == 0) {
2147                 if (dest->nonnull) {
2148                         /* bash man page calls this an "explicit" null */
2149                         gr = globhack(dest->data, flags, pglob);
2150                         debug_printf("globhack returned %d\n",gr);
2151                 } else {
2152                         return 0;
2153                 }
2154         } else if (glob_needed(dest->data)) {
2155                 gr = glob(dest->data, flags, NULL, pglob);
2156                 debug_printf("glob returned %d\n",gr);
2157                 if (gr == GLOB_NOMATCH) {
2158                         /* quote removal, or more accurately, backslash removal */
2159                         gr = globhack(dest->data, flags, pglob);
2160                         debug_printf("globhack returned %d\n",gr);
2161                 }
2162         } else {
2163                 gr = globhack(dest->data, flags, pglob);
2164                 debug_printf("globhack returned %d\n",gr);
2165         }
2166         if (gr == GLOB_NOSPACE)
2167                 error_msg_and_die("out of memory during glob");
2168         if (gr != 0) { /* GLOB_ABORTED ? */
2169                 error_msg("glob(3) error %d",gr);
2170         }
2171         /* globprint(glob_target); */
2172         return gr;
2173 }
2174 #endif
2175
2176 #ifdef __U_BOOT__
2177 static char *get_dollar_var(char ch);
2178 #endif
2179
2180 /* This is used to get/check local shell variables */
2181 static char *get_local_var(const char *s)
2182 {
2183         struct variables *cur;
2184
2185         if (!s)
2186                 return NULL;
2187
2188 #ifdef __U_BOOT__
2189         if (*s == '$')
2190                 return get_dollar_var(s[1]);
2191 #endif
2192
2193         for (cur = top_vars; cur; cur=cur->next)
2194                 if(strcmp(cur->name, s)==0)
2195                         return cur->value;
2196         return NULL;
2197 }
2198
2199 /* This is used to set local shell variables
2200    flg_export==0 if only local (not exporting) variable
2201    flg_export==1 if "new" exporting environ
2202    flg_export>1  if current startup environ (not call putenv()) */
2203 static int set_local_var(const char *s, int flg_export)
2204 {
2205         char *name, *value;
2206         int result=0;
2207         struct variables *cur;
2208
2209 #ifdef __U_BOOT__
2210         /* might be possible! */
2211         if (!isalpha(*s))
2212                 return -1;
2213 #endif
2214
2215         name=strdup(s);
2216
2217 #ifdef __U_BOOT__
2218         if (getenv(name) != NULL) {
2219                 printf ("ERROR: "
2220                                 "There is a global environment variable with the same name.\n");
2221                 free(name);
2222                 return -1;
2223         }
2224 #endif
2225         /* Assume when we enter this function that we are already in
2226          * NAME=VALUE format.  So the first order of business is to
2227          * split 's' on the '=' into 'name' and 'value' */
2228         value = strchr(name, '=');
2229         if (value==0 && ++value==0) {
2230                 free(name);
2231                 return -1;
2232         }
2233         *value++ = 0;
2234
2235         for(cur = top_vars; cur; cur = cur->next) {
2236                 if(strcmp(cur->name, name)==0)
2237                         break;
2238         }
2239
2240         if(cur) {
2241                 if(strcmp(cur->value, value)==0) {
2242                         if(flg_export>0 && cur->flg_export==0)
2243                                 cur->flg_export=flg_export;
2244                         else
2245                                 result++;
2246                 } else {
2247                         if(cur->flg_read_only) {
2248                                 error_msg("%s: readonly variable", name);
2249                                 result = -1;
2250                         } else {
2251                                 if(flg_export>0 || cur->flg_export>1)
2252                                         cur->flg_export=1;
2253                                 free(cur->value);
2254
2255                                 cur->value = strdup(value);
2256                         }
2257                 }
2258         } else {
2259                 cur = malloc(sizeof(struct variables));
2260                 if(!cur) {
2261                         result = -1;
2262                 } else {
2263                         cur->name = strdup(name);
2264                         if(cur->name == 0) {
2265                                 free(cur);
2266                                 result = -1;
2267                         } else {
2268                                 struct variables *bottom = top_vars;
2269                                 cur->value = strdup(value);
2270                                 cur->next = 0;
2271                                 cur->flg_export = flg_export;
2272                                 cur->flg_read_only = 0;
2273                                 while(bottom->next) bottom=bottom->next;
2274                                 bottom->next = cur;
2275                         }
2276                 }
2277         }
2278
2279 #ifndef __U_BOOT__
2280         if(result==0 && cur->flg_export==1) {
2281                 *(value-1) = '=';
2282                 result = putenv(name);
2283         } else {
2284 #endif
2285                 free(name);
2286 #ifndef __U_BOOT__
2287                 if(result>0)            /* equivalent to previous set */
2288                         result = 0;
2289         }
2290 #endif
2291         return result;
2292 }
2293
2294 #ifndef __U_BOOT__
2295 static void unset_local_var(const char *name)
2296 {
2297         struct variables *cur;
2298
2299         if (name) {
2300                 for (cur = top_vars; cur; cur=cur->next) {
2301                         if(strcmp(cur->name, name)==0)
2302                                 break;
2303                 }
2304                 if(cur!=0) {
2305                         struct variables *next = top_vars;
2306                         if(cur->flg_read_only) {
2307                                 error_msg("%s: readonly variable", name);
2308                                 return;
2309                         } else {
2310                                 if(cur->flg_export)
2311                                         unsetenv(cur->name);
2312                                 free(cur->name);
2313                                 free(cur->value);
2314                                 while (next->next != cur)
2315                                         next = next->next;
2316                                 next->next = cur->next;
2317                         }
2318                         free(cur);
2319                 }
2320         }
2321 }
2322 #endif
2323
2324 static int is_assignment(const char *s)
2325 {
2326         if (s == NULL)
2327                 return 0;
2328
2329         if (!isalpha(*s)) return 0;
2330         ++s;
2331         while(isalnum(*s) || *s=='_') ++s;
2332         return *s=='=';
2333 }
2334
2335 #ifndef __U_BOOT__
2336 /* the src parameter allows us to peek forward to a possible &n syntax
2337  * for file descriptor duplication, e.g., "2>&1".
2338  * Return code is 0 normally, 1 if a syntax error is detected in src.
2339  * Resource errors (in xmalloc) cause the process to exit */
2340 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2341         struct in_str *input)
2342 {
2343         struct child_prog *child=ctx->child;
2344         struct redir_struct *redir = child->redirects;
2345         struct redir_struct *last_redir=NULL;
2346
2347         /* Create a new redir_struct and drop it onto the end of the linked list */
2348         while(redir) {
2349                 last_redir=redir;
2350                 redir=redir->next;
2351         }
2352         redir = xmalloc(sizeof(struct redir_struct));
2353         redir->next=NULL;
2354         redir->word.gl_pathv=NULL;
2355         if (last_redir) {
2356                 last_redir->next=redir;
2357         } else {
2358                 child->redirects=redir;
2359         }
2360
2361         redir->type=style;
2362         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2363
2364         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2365
2366         /* Check for a '2>&1' type redirect */
2367         redir->dup = redirect_dup_num(input);
2368         if (redir->dup == -2) return 1;  /* syntax error */
2369         if (redir->dup != -1) {
2370                 /* Erik had a check here that the file descriptor in question
2371                  * is legit; I postpone that to "run time"
2372                  * A "-" representation of "close me" shows up as a -3 here */
2373                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2374         } else {
2375                 /* We do _not_ try to open the file that src points to,
2376                  * since we need to return and let src be expanded first.
2377                  * Set ctx->pending_redirect, so we know what to do at the
2378                  * end of the next parsed word.
2379                  */
2380                 ctx->pending_redirect = redir;
2381         }
2382         return 0;
2383 }
2384 #endif
2385
2386 struct pipe *new_pipe(void) {
2387         struct pipe *pi;
2388         pi = xmalloc(sizeof(struct pipe));
2389         pi->num_progs = 0;
2390         pi->progs = NULL;
2391         pi->next = NULL;
2392         pi->followup = 0;  /* invalid */
2393         pi->r_mode = RES_NONE;
2394         return pi;
2395 }
2396
2397 static void initialize_context(struct p_context *ctx)
2398 {
2399         ctx->pipe=NULL;
2400 #ifndef __U_BOOT__
2401         ctx->pending_redirect=NULL;
2402 #endif
2403         ctx->child=NULL;
2404         ctx->list_head=new_pipe();
2405         ctx->pipe=ctx->list_head;
2406         ctx->w=RES_NONE;
2407         ctx->stack=NULL;
2408 #ifdef __U_BOOT__
2409         ctx->old_flag=0;
2410 #endif
2411         done_command(ctx);   /* creates the memory for working child */
2412 }
2413
2414 /* normal return is 0
2415  * if a reserved word is found, and processed, return 1
2416  * should handle if, then, elif, else, fi, for, while, until, do, done.
2417  * case, function, and select are obnoxious, save those for later.
2418  */
2419 struct reserved_combo {
2420         char *literal;
2421         int code;
2422         long flag;
2423 };
2424 /* Mostly a list of accepted follow-up reserved words.
2425  * FLAG_END means we are done with the sequence, and are ready
2426  * to turn the compound list into a command.
2427  * FLAG_START means the word must start a new compound list.
2428  */
2429 static struct reserved_combo reserved_list[] = {
2430         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2431         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2432         { "elif",  RES_ELIF,  FLAG_THEN },
2433         { "else",  RES_ELSE,  FLAG_FI   },
2434         { "fi",    RES_FI,    FLAG_END  },
2435         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2436         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2437         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2438         { "in",    RES_IN,    FLAG_DO   },
2439         { "do",    RES_DO,    FLAG_DONE },
2440         { "done",  RES_DONE,  FLAG_END  }
2441 };
2442 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2443
2444 int reserved_word(o_string *dest, struct p_context *ctx)
2445 {
2446         struct reserved_combo *r;
2447         for (r=reserved_list;
2448                 r<reserved_list+NRES; r++) {
2449                 if (strcmp(dest->data, r->literal) == 0) {
2450                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2451                         if (r->flag & FLAG_START) {
2452                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2453                                 debug_printf("push stack\n");
2454                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2455                                         syntax();
2456                                         free(new);
2457                                         ctx->w = RES_SNTX;
2458                                         b_reset(dest);
2459                                         return 1;
2460                                 }
2461                                 *new = *ctx;   /* physical copy */
2462                                 initialize_context(ctx);
2463                                 ctx->stack=new;
2464                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2465                                 syntax();
2466                                 ctx->w = RES_SNTX;
2467                                 b_reset(dest);
2468                                 return 1;
2469                         }
2470                         ctx->w=r->code;
2471                         ctx->old_flag = r->flag;
2472                         if (ctx->old_flag & FLAG_END) {
2473                                 struct p_context *old;
2474                                 debug_printf("pop stack\n");
2475                                 done_pipe(ctx,PIPE_SEQ);
2476                                 old = ctx->stack;
2477                                 old->child->group = ctx->list_head;
2478 #ifndef __U_BOOT__
2479                                 old->child->subshell = 0;
2480 #endif
2481                                 *ctx = *old;   /* physical copy */
2482                                 free(old);
2483                         }
2484                         b_reset (dest);
2485                         return 1;
2486                 }
2487         }
2488         return 0;
2489 }
2490
2491 /* normal return is 0.
2492  * Syntax or xglob errors return 1. */
2493 static int done_word(o_string *dest, struct p_context *ctx)
2494 {
2495         struct child_prog *child=ctx->child;
2496 #ifndef __U_BOOT__
2497         glob_t *glob_target;
2498         int gr, flags = 0;
2499 #else
2500         char *str, *s;
2501         int argc, cnt;
2502 #endif
2503
2504         debug_printf("done_word: %s %p\n", dest->data, child);
2505         if (dest->length == 0 && !dest->nonnull) {
2506                 debug_printf("  true null, ignored\n");
2507                 return 0;
2508         }
2509 #ifndef __U_BOOT__
2510         if (ctx->pending_redirect) {
2511                 glob_target = &ctx->pending_redirect->word;
2512         } else {
2513 #endif
2514                 if (child->group) {
2515                         syntax();
2516                         return 1;  /* syntax error, groups and arglists don't mix */
2517                 }
2518                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2519                         debug_printf("checking %s for reserved-ness\n",dest->data);
2520                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2521                 }
2522 #ifndef __U_BOOT__
2523                 glob_target = &child->glob_result;
2524                 if (child->argv) flags |= GLOB_APPEND;
2525 #else
2526                 for (cnt = 1, s = dest->data; s && *s; s++) {
2527                         if (*s == '\\') s++;
2528                         cnt++;
2529                 }
2530                 str = malloc(cnt);
2531                 if (!str) return 1;
2532                 if ( child->argv == NULL) {
2533                         child->argc=0;
2534                 }
2535                 argc = ++child->argc;
2536                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2537                 if (child->argv == NULL) return 1;
2538                 child->argv[argc-1]=str;
2539                 child->argv[argc]=NULL;
2540                 for (s = dest->data; s && *s; s++,str++) {
2541                         if (*s == '\\') s++;
2542                         *str = *s;
2543                 }
2544                 *str = '\0';
2545 #endif
2546 #ifndef __U_BOOT__
2547         }
2548         gr = xglob(dest, flags, glob_target);
2549         if (gr != 0) return 1;
2550 #endif
2551
2552         b_reset(dest);
2553 #ifndef __U_BOOT__
2554         if (ctx->pending_redirect) {
2555                 ctx->pending_redirect=NULL;
2556                 if (glob_target->gl_pathc != 1) {
2557                         error_msg("ambiguous redirect");
2558                         return 1;
2559                 }
2560         } else {
2561                 child->argv = glob_target->gl_pathv;
2562         }
2563 #endif
2564         if (ctx->w == RES_FOR) {
2565                 done_word(dest,ctx);
2566                 done_pipe(ctx,PIPE_SEQ);
2567         }
2568         return 0;
2569 }
2570
2571 /* The only possible error here is out of memory, in which case
2572  * xmalloc exits. */
2573 static int done_command(struct p_context *ctx)
2574 {
2575         /* The child is really already in the pipe structure, so
2576          * advance the pipe counter and make a new, null child.
2577          * Only real trickiness here is that the uncommitted
2578          * child structure, to which ctx->child points, is not
2579          * counted in pi->num_progs. */
2580         struct pipe *pi=ctx->pipe;
2581         struct child_prog *prog=ctx->child;
2582
2583         if (prog && prog->group == NULL
2584                  && prog->argv == NULL
2585 #ifndef __U_BOOT__
2586                  && prog->redirects == NULL) {
2587 #else
2588                                                                                 ) {
2589 #endif
2590                 debug_printf("done_command: skipping null command\n");
2591                 return 0;
2592         } else if (prog) {
2593                 pi->num_progs++;
2594                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2595         } else {
2596                 debug_printf("done_command: initializing\n");
2597         }
2598         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2599
2600         prog = pi->progs + pi->num_progs;
2601 #ifndef __U_BOOT__
2602         prog->redirects = NULL;
2603 #endif
2604         prog->argv = NULL;
2605 #ifndef __U_BOOT__
2606         prog->is_stopped = 0;
2607 #endif
2608         prog->group = NULL;
2609 #ifndef __U_BOOT__
2610         prog->glob_result.gl_pathv = NULL;
2611         prog->family = pi;
2612 #endif
2613         prog->sp = 0;
2614         ctx->child = prog;
2615         prog->type = ctx->type;
2616
2617         /* but ctx->pipe and ctx->list_head remain unchanged */
2618         return 0;
2619 }
2620
2621 static int done_pipe(struct p_context *ctx, pipe_style type)
2622 {
2623         struct pipe *new_p;
2624         done_command(ctx);  /* implicit closure of previous command */
2625         debug_printf("done_pipe, type %d\n", type);
2626         ctx->pipe->followup = type;
2627         ctx->pipe->r_mode = ctx->w;
2628         new_p=new_pipe();
2629         ctx->pipe->next = new_p;
2630         ctx->pipe = new_p;
2631         ctx->child = NULL;
2632         done_command(ctx);  /* set up new pipe to accept commands */
2633         return 0;
2634 }
2635
2636 #ifndef __U_BOOT__
2637 /* peek ahead in the in_str to find out if we have a "&n" construct,
2638  * as in "2>&1", that represents duplicating a file descriptor.
2639  * returns either -2 (syntax error), -1 (no &), or the number found.
2640  */
2641 static int redirect_dup_num(struct in_str *input)
2642 {
2643         int ch, d=0, ok=0;
2644         ch = b_peek(input);
2645         if (ch != '&') return -1;
2646
2647         b_getch(input);  /* get the & */
2648         ch=b_peek(input);
2649         if (ch == '-') {
2650                 b_getch(input);
2651                 return -3;  /* "-" represents "close me" */
2652         }
2653         while (isdigit(ch)) {
2654                 d = d*10+(ch-'0');
2655                 ok=1;
2656                 b_getch(input);
2657                 ch = b_peek(input);
2658         }
2659         if (ok) return d;
2660
2661         error_msg("ambiguous redirect");
2662         return -2;
2663 }
2664
2665 /* If a redirect is immediately preceded by a number, that number is
2666  * supposed to tell which file descriptor to redirect.  This routine
2667  * looks for such preceding numbers.  In an ideal world this routine
2668  * needs to handle all the following classes of redirects...
2669  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2670  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2671  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2672  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2673  * A -1 output from this program means no valid number was found, so the
2674  * caller should use the appropriate default for this redirection.
2675  */
2676 static int redirect_opt_num(o_string *o)
2677 {
2678         int num;
2679
2680         if (o->length==0) return -1;
2681         for(num=0; num<o->length; num++) {
2682                 if (!isdigit(*(o->data+num))) {
2683                         return -1;
2684                 }
2685         }
2686         /* reuse num (and save an int) */
2687         num=atoi(o->data);
2688         b_reset(o);
2689         return num;
2690 }
2691
2692 FILE *generate_stream_from_list(struct pipe *head)
2693 {
2694         FILE *pf;
2695 #if 1
2696         int pid, channel[2];
2697         if (pipe(channel)<0) perror_msg_and_die("pipe");
2698         pid=fork();
2699         if (pid<0) {
2700                 perror_msg_and_die("fork");
2701         } else if (pid==0) {
2702                 close(channel[0]);
2703                 if (channel[1] != 1) {
2704                         dup2(channel[1],1);
2705                         close(channel[1]);
2706                 }
2707 #if 0
2708 #define SURROGATE "surrogate response"
2709                 write(1,SURROGATE,sizeof(SURROGATE));
2710                 _exit(run_list(head));
2711 #else
2712                 _exit(run_list_real(head));   /* leaks memory */
2713 #endif
2714         }
2715         debug_printf("forked child %d\n",pid);
2716         close(channel[1]);
2717         pf = fdopen(channel[0],"r");
2718         debug_printf("pipe on FILE *%p\n",pf);
2719 #else
2720         free_pipe_list(head,0);
2721         pf=popen("echo surrogate response","r");
2722         debug_printf("started fake pipe on FILE *%p\n",pf);
2723 #endif
2724         return pf;
2725 }
2726
2727 /* this version hacked for testing purposes */
2728 /* return code is exit status of the process that is run. */
2729 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2730 {
2731         int retcode;
2732         o_string result=NULL_O_STRING;
2733         struct p_context inner;
2734         FILE *p;
2735         struct in_str pipe_str;
2736         initialize_context(&inner);
2737
2738         /* recursion to generate command */
2739         retcode = parse_stream(&result, &inner, input, subst_end);
2740         if (retcode != 0) return retcode;  /* syntax error or EOF */
2741         done_word(&result, &inner);
2742         done_pipe(&inner, PIPE_SEQ);
2743         b_free(&result);
2744
2745         p=generate_stream_from_list(inner.list_head);
2746         if (p==NULL) return 1;
2747         mark_open(fileno(p));
2748         setup_file_in_str(&pipe_str, p);
2749
2750         /* now send results of command back into original context */
2751         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2752         /* XXX In case of a syntax error, should we try to kill the child?
2753          * That would be tough to do right, so just read until EOF. */
2754         if (retcode == 1) {
2755                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2756         }
2757
2758         debug_printf("done reading from pipe, pclose()ing\n");
2759         /* This is the step that wait()s for the child.  Should be pretty
2760          * safe, since we just read an EOF from its stdout.  We could try
2761          * to better, by using wait(), and keeping track of background jobs
2762          * at the same time.  That would be a lot of work, and contrary
2763          * to the KISS philosophy of this program. */
2764         mark_closed(fileno(p));
2765         retcode=pclose(p);
2766         free_pipe_list(inner.list_head,0);
2767         debug_printf("pclosed, retcode=%d\n",retcode);
2768         /* XXX this process fails to trim a single trailing newline */
2769         return retcode;
2770 }
2771
2772 static int parse_group(o_string *dest, struct p_context *ctx,
2773         struct in_str *input, int ch)
2774 {
2775         int rcode, endch=0;
2776         struct p_context sub;
2777         struct child_prog *child = ctx->child;
2778         if (child->argv) {
2779                 syntax();
2780                 return 1;  /* syntax error, groups and arglists don't mix */
2781         }
2782         initialize_context(&sub);
2783         switch(ch) {
2784                 case '(': endch=')'; child->subshell=1; break;
2785                 case '{': endch='}'; break;
2786                 default: syntax();   /* really logic error */
2787         }
2788         rcode=parse_stream(dest,&sub,input,endch);
2789         done_word(dest,&sub); /* finish off the final word in the subcontext */
2790         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2791         child->group = sub.list_head;
2792         return rcode;
2793         /* child remains "open", available for possible redirects */
2794 }
2795 #endif
2796
2797 /* basically useful version until someone wants to get fancier,
2798  * see the bash man page under "Parameter Expansion" */
2799 static char *lookup_param(char *src)
2800 {
2801         char *p;
2802
2803         if (!src)
2804                 return NULL;
2805
2806                 p = getenv(src);
2807                 if (!p)
2808                         p = get_local_var(src);
2809
2810         return p;
2811 }
2812
2813 #ifdef __U_BOOT__
2814 static char *get_dollar_var(char ch)
2815 {
2816         static char buf[40];
2817
2818         buf[0] = '\0';
2819         switch (ch) {
2820                 case '?':
2821                         sprintf(buf, "%u", (unsigned int)last_return_code);
2822                         break;
2823                 default:
2824                         return NULL;
2825         }
2826         return buf;
2827 }
2828 #endif
2829
2830 /* return code: 0 for OK, 1 for syntax error */
2831 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2832 {
2833 #ifndef __U_BOOT__
2834         int i, advance=0;
2835 #else
2836         int advance=0;
2837 #endif
2838 #ifndef __U_BOOT__
2839         char sep[]=" ";
2840 #endif
2841         int ch = input->peek(input);  /* first character after the $ */
2842         debug_printf("handle_dollar: ch=%c\n",ch);
2843         if (isalpha(ch)) {
2844                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2845                 ctx->child->sp++;
2846                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2847                         b_getch(input);
2848                         b_addchr(dest,ch);
2849                 }
2850                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851 #ifndef __U_BOOT__
2852         } else if (isdigit(ch)) {
2853                 i = ch-'0';  /* XXX is $0 special? */
2854                 if (i<global_argc) {
2855                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2856                 }
2857                 advance = 1;
2858 #endif
2859         } else switch (ch) {
2860 #ifndef __U_BOOT__
2861                 case '$':
2862                         b_adduint(dest,getpid());
2863                         advance = 1;
2864                         break;
2865                 case '!':
2866                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2867                         advance = 1;
2868                         break;
2869 #endif
2870                 case '?':
2871 #ifndef __U_BOOT__
2872                         b_adduint(dest,last_return_code);
2873 #else
2874                         ctx->child->sp++;
2875                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2876                         b_addchr(dest, '$');
2877                         b_addchr(dest, '?');
2878                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2879 #endif
2880                         advance = 1;
2881                         break;
2882 #ifndef __U_BOOT__
2883                 case '#':
2884                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2885                         advance = 1;
2886                         break;
2887 #endif
2888                 case '{':
2889                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2890                         ctx->child->sp++;
2891                         b_getch(input);
2892                         /* XXX maybe someone will try to escape the '}' */
2893                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2894                                 b_addchr(dest,ch);
2895                         }
2896                         if (ch != '}') {
2897                                 syntax();
2898                                 return 1;
2899                         }
2900                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2901                         break;
2902 #ifndef __U_BOOT__
2903                 case '(':
2904                         b_getch(input);
2905                         process_command_subs(dest, ctx, input, ')');
2906                         break;
2907                 case '*':
2908                         sep[0]=ifs[0];
2909                         for (i=1; i<global_argc; i++) {
2910                                 parse_string(dest, ctx, global_argv[i]);
2911                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2912                         }
2913                         break;
2914                 case '@':
2915                 case '-':
2916                 case '_':
2917                         /* still unhandled, but should be eventually */
2918                         error_msg("unhandled syntax: $%c",ch);
2919                         return 1;
2920                         break;
2921 #endif
2922                 default:
2923                         b_addqchr(dest,'$',dest->quote);
2924         }
2925         /* Eat the character if the flag was set.  If the compiler
2926          * is smart enough, we could substitute "b_getch(input);"
2927          * for all the "advance = 1;" above, and also end up with
2928          * a nice size-optimized program.  Hah!  That'll be the day.
2929          */
2930         if (advance) b_getch(input);
2931         return 0;
2932 }
2933
2934 #ifndef __U_BOOT__
2935 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2936 {
2937         struct in_str foo;
2938         setup_string_in_str(&foo, src);
2939         return parse_stream(dest, ctx, &foo, '\0');
2940 }
2941 #endif
2942
2943 /* return code is 0 for normal exit, 1 for syntax error */
2944 int parse_stream(o_string *dest, struct p_context *ctx,
2945         struct in_str *input, int end_trigger)
2946 {
2947         unsigned int ch, m;
2948 #ifndef __U_BOOT__
2949         int redir_fd;
2950         redir_type redir_style;
2951 #endif
2952         int next;
2953
2954         /* Only double-quote state is handled in the state variable dest->quote.
2955          * A single-quote triggers a bypass of the main loop until its mate is
2956          * found.  When recursing, quote state is passed in via dest->quote. */
2957
2958         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2959         while ((ch=b_getch(input))!=EOF) {
2960                 m = map[ch];
2961 #ifdef __U_BOOT__
2962                 if (input->__promptme == 0) return 1;
2963 #endif
2964                 next = (ch == '\n') ? 0 : b_peek(input);
2965
2966                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2967                         ch >= ' ' ? ch : '.', ch, m,
2968                         dest->quote, ctx->stack == NULL ? '*' : '.');
2969
2970                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2971                         b_addqchr(dest, ch, dest->quote);
2972                 } else {
2973                         if (m==2) {  /* unquoted IFS */
2974                                 if (done_word(dest, ctx)) {
2975                                         return 1;
2976                                 }
2977                                 /* If we aren't performing a substitution, treat a newline as a
2978                                  * command separator.  */
2979                                 if (end_trigger != '\0' && ch=='\n')
2980                                         done_pipe(ctx,PIPE_SEQ);
2981                         }
2982                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2983                                 debug_printf("leaving parse_stream (triggered)\n");
2984                                 return 0;
2985                         }
2986 #if 0
2987                         if (ch=='\n') {
2988                                 /* Yahoo!  Time to run with it! */
2989                                 done_pipe(ctx,PIPE_SEQ);
2990                                 run_list(ctx->list_head);
2991                                 initialize_context(ctx);
2992                         }
2993 #endif
2994                         if (m!=2) switch (ch) {
2995                 case '#':
2996                         if (dest->length == 0 && !dest->quote) {
2997                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2998                         } else {
2999                                 b_addqchr(dest, ch, dest->quote);
3000                         }
3001                         break;
3002                 case '\\':
3003                         if (next == EOF) {
3004                                 syntax();
3005                                 return 1;
3006                         }
3007                         b_addqchr(dest, '\\', dest->quote);
3008                         b_addqchr(dest, b_getch(input), dest->quote);
3009                         break;
3010                 case '$':
3011                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3012                         break;
3013                 case '\'':
3014                         dest->nonnull = 1;
3015                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3016 #ifdef __U_BOOT__
3017                                 if(input->__promptme == 0) return 1;
3018 #endif
3019                                 b_addchr(dest,ch);
3020                         }
3021                         if (ch==EOF) {
3022                                 syntax();
3023                                 return 1;
3024                         }
3025                         break;
3026                 case '"':
3027                         dest->nonnull = 1;
3028                         dest->quote = !dest->quote;
3029                         break;
3030 #ifndef __U_BOOT__
3031                 case '`':
3032                         process_command_subs(dest, ctx, input, '`');
3033                         break;
3034                 case '>':
3035                         redir_fd = redirect_opt_num(dest);
3036                         done_word(dest, ctx);
3037                         redir_style=REDIRECT_OVERWRITE;
3038                         if (next == '>') {
3039                                 redir_style=REDIRECT_APPEND;
3040                                 b_getch(input);
3041                         } else if (next == '(') {
3042                                 syntax();   /* until we support >(list) Process Substitution */
3043                                 return 1;
3044                         }
3045                         setup_redirect(ctx, redir_fd, redir_style, input);
3046                         break;
3047                 case '<':
3048                         redir_fd = redirect_opt_num(dest);
3049                         done_word(dest, ctx);
3050                         redir_style=REDIRECT_INPUT;
3051                         if (next == '<') {
3052                                 redir_style=REDIRECT_HEREIS;
3053                                 b_getch(input);
3054                         } else if (next == '>') {
3055                                 redir_style=REDIRECT_IO;
3056                                 b_getch(input);
3057                         } else if (next == '(') {
3058                                 syntax();   /* until we support <(list) Process Substitution */
3059                                 return 1;
3060                         }
3061                         setup_redirect(ctx, redir_fd, redir_style, input);
3062                         break;
3063 #endif
3064                 case ';':
3065                         done_word(dest, ctx);
3066                         done_pipe(ctx,PIPE_SEQ);
3067                         break;
3068                 case '&':
3069                         done_word(dest, ctx);
3070                         if (next=='&') {
3071                                 b_getch(input);
3072                                 done_pipe(ctx,PIPE_AND);
3073                         } else {
3074 #ifndef __U_BOOT__
3075                                 done_pipe(ctx,PIPE_BG);
3076 #else
3077                                 syntax_err();
3078                                 return 1;
3079 #endif
3080                         }
3081                         break;
3082                 case '|':
3083                         done_word(dest, ctx);
3084                         if (next=='|') {
3085                                 b_getch(input);
3086                                 done_pipe(ctx,PIPE_OR);
3087                         } else {
3088                                 /* we could pick up a file descriptor choice here
3089                                  * with redirect_opt_num(), but bash doesn't do it.
3090                                  * "echo foo 2| cat" yields "foo 2". */
3091 #ifndef __U_BOOT__
3092                                 done_command(ctx);
3093 #else
3094                                 syntax_err();
3095                                 return 1;
3096 #endif
3097                         }
3098                         break;
3099 #ifndef __U_BOOT__
3100                 case '(':
3101                 case '{':
3102                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3103                         break;
3104                 case ')':
3105                 case '}':
3106                         syntax();   /* Proper use of this character caught by end_trigger */
3107                         return 1;
3108                         break;
3109 #endif
3110                 default:
3111                         syntax();   /* this is really an internal logic error */
3112                         return 1;
3113                         }
3114                 }
3115         }
3116         /* complain if quote?  No, maybe we just finished a command substitution
3117          * that was quoted.  Example:
3118          * $ echo "`cat foo` plus more"
3119          * and we just got the EOF generated by the subshell that ran "cat foo"
3120          * The only real complaint is if we got an EOF when end_trigger != '\0',
3121          * that is, we were really supposed to get end_trigger, and never got
3122          * one before the EOF.  Can't use the standard "syntax error" return code,
3123          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3124         debug_printf("leaving parse_stream (EOF)\n");
3125         if (end_trigger != '\0') return -1;
3126         return 0;
3127 }
3128
3129 void mapset(const unsigned char *set, int code)
3130 {
3131         const unsigned char *s;
3132         for (s=set; *s; s++) map[*s] = code;
3133 }
3134
3135 void update_ifs_map(void)
3136 {
3137         /* char *ifs and char map[256] are both globals. */
3138         ifs = (uchar *)getenv("IFS");
3139         if (ifs == NULL) ifs=(uchar *)" \t\n";
3140         /* Precompute a list of 'flow through' behavior so it can be treated
3141          * quickly up front.  Computation is necessary because of IFS.
3142          * Special case handling of IFS == " \t\n" is not implemented.
3143          * The map[] array only really needs two bits each, and on most machines
3144          * that would be faster because of the reduced L1 cache footprint.
3145          */
3146         memset(map,0,sizeof(map)); /* most characters flow through always */
3147 #ifndef __U_BOOT__
3148         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3149         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3150 #else
3151         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3152         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3153 #endif
3154         mapset(ifs, 2);            /* also flow through if quoted */
3155 }
3156
3157 /* most recursion does not come through here, the exeception is
3158  * from builtin_source() */
3159 int parse_stream_outer(struct in_str *inp, int flag)
3160 {
3161
3162         struct p_context ctx;
3163         o_string temp=NULL_O_STRING;
3164         int rcode;
3165 #ifdef __U_BOOT__
3166         int code = 0;
3167 #endif
3168         do {
3169                 ctx.type = flag;
3170                 initialize_context(&ctx);
3171                 update_ifs_map();
3172                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3173                 inp->promptmode=1;
3174                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3175 #ifdef __U_BOOT__
3176                 if (rcode == 1) flag_repeat = 0;
3177 #endif
3178                 if (rcode != 1 && ctx.old_flag != 0) {
3179                         syntax();
3180 #ifdef __U_BOOT__
3181                         flag_repeat = 0;
3182 #endif
3183                 }
3184                 if (rcode != 1 && ctx.old_flag == 0) {
3185                         done_word(&temp, &ctx);
3186                         done_pipe(&ctx,PIPE_SEQ);
3187 #ifndef __U_BOOT__
3188                         run_list(ctx.list_head);
3189 #else
3190                         code = run_list(ctx.list_head);
3191                         if (code == -2) {       /* exit */
3192                                 b_free(&temp);
3193                                 code = 0;
3194                                 /* XXX hackish way to not allow exit from main loop */
3195                                 if (inp->peek == file_peek) {
3196                                         printf("exit not allowed from main input shell.\n");
3197                                         continue;
3198                                 }
3199                                 break;
3200                         }
3201                         if (code == -1)
3202                             flag_repeat = 0;
3203 #endif
3204                 } else {
3205                         if (ctx.old_flag != 0) {
3206                                 free(ctx.stack);
3207                                 b_reset(&temp);
3208                         }
3209 #ifdef __U_BOOT__
3210                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3211                         inp->__promptme = 1;
3212 #endif
3213                         temp.nonnull = 0;
3214                         temp.quote = 0;
3215                         inp->p = NULL;
3216                         free_pipe_list(ctx.list_head,0);
3217                 }
3218                 b_free(&temp);
3219         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3220 #ifndef __U_BOOT__
3221         return 0;
3222 #else
3223         return (code != 0) ? 1 : 0;
3224 #endif /* __U_BOOT__ */
3225 }
3226
3227 #ifndef __U_BOOT__
3228 static int parse_string_outer(const char *s, int flag)
3229 #else
3230 int parse_string_outer(char *s, int flag)
3231 #endif  /* __U_BOOT__ */
3232 {
3233         struct in_str input;
3234 #ifdef __U_BOOT__
3235         char *p = NULL;
3236         int rcode;
3237         if ( !s || !*s)
3238                 return 1;
3239         if (!(p = strchr(s, '\n')) || *++p) {
3240                 p = xmalloc(strlen(s) + 2);
3241                 strcpy(p, s);
3242                 strcat(p, "\n");
3243                 setup_string_in_str(&input, p);
3244                 rcode = parse_stream_outer(&input, flag);
3245                 free(p);
3246                 return rcode;
3247         } else {
3248 #endif
3249         setup_string_in_str(&input, s);
3250         return parse_stream_outer(&input, flag);
3251 #ifdef __U_BOOT__
3252         }
3253 #endif
3254 }
3255
3256 #ifndef __U_BOOT__
3257 static int parse_file_outer(FILE *f)
3258 #else
3259 int parse_file_outer(void)
3260 #endif
3261 {
3262         int rcode;
3263         struct in_str input;
3264 #ifndef __U_BOOT__
3265         setup_file_in_str(&input, f);
3266 #else
3267         setup_file_in_str(&input);
3268 #endif
3269         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3270         return rcode;
3271 }
3272
3273 #ifdef __U_BOOT__
3274 static void u_boot_hush_reloc(void)
3275 {
3276         unsigned long addr;
3277         struct reserved_combo *r;
3278
3279         for (r=reserved_list; r<reserved_list+NRES; r++) {
3280                 addr = (ulong) (r->literal) + gd->reloc_off;
3281                 r->literal = (char *)addr;
3282         }
3283 }
3284
3285 int u_boot_hush_start(void)
3286 {
3287         if (top_vars == NULL) {
3288                 top_vars = malloc(sizeof(struct variables));
3289                 top_vars->name = "HUSH_VERSION";
3290                 top_vars->value = "0.01";
3291                 top_vars->next = 0;
3292                 top_vars->flg_export = 0;
3293                 top_vars->flg_read_only = 1;
3294                 u_boot_hush_reloc();
3295         }
3296         return 0;
3297 }
3298
3299 static void *xmalloc(size_t size)
3300 {
3301         void *p = NULL;
3302
3303         if (!(p = malloc(size))) {
3304             printf("ERROR : memory not allocated\n");
3305             for(;;);
3306         }
3307         return p;
3308 }
3309
3310 static void *xrealloc(void *ptr, size_t size)
3311 {
3312         void *p = NULL;
3313
3314         if (!(p = realloc(ptr, size))) {
3315             printf("ERROR : memory not allocated\n");
3316             for(;;);
3317         }
3318         return p;
3319 }
3320 #endif /* __U_BOOT__ */
3321
3322 #ifndef __U_BOOT__
3323 /* Make sure we have a controlling tty.  If we get started under a job
3324  * aware app (like bash for example), make sure we are now in charge so
3325  * we don't fight over who gets the foreground */
3326 static void setup_job_control(void)
3327 {
3328         static pid_t shell_pgrp;
3329         /* Loop until we are in the foreground.  */
3330         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3331                 kill (- shell_pgrp, SIGTTIN);
3332
3333         /* Ignore interactive and job-control signals.  */
3334         signal(SIGINT, SIG_IGN);
3335         signal(SIGQUIT, SIG_IGN);
3336         signal(SIGTERM, SIG_IGN);
3337         signal(SIGTSTP, SIG_IGN);
3338         signal(SIGTTIN, SIG_IGN);
3339         signal(SIGTTOU, SIG_IGN);
3340         signal(SIGCHLD, SIG_IGN);
3341
3342         /* Put ourselves in our own process group.  */
3343         setsid();
3344         shell_pgrp = getpid ();
3345         setpgid (shell_pgrp, shell_pgrp);
3346
3347         /* Grab control of the terminal.  */
3348         tcsetpgrp(shell_terminal, shell_pgrp);
3349 }
3350
3351 int hush_main(int argc, char **argv)
3352 {
3353         int opt;
3354         FILE *input;
3355         char **e = environ;
3356
3357         /* XXX what should these be while sourcing /etc/profile? */
3358         global_argc = argc;
3359         global_argv = argv;
3360
3361         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3362          * hush_main(), therefore we cannot rely on the BSS to zero out this
3363          * stuff.  Reset these to 0 every time. */
3364         ifs = NULL;
3365         /* map[] is taken care of with call to update_ifs_map() */
3366         fake_mode = 0;
3367         interactive = 0;
3368         close_me_head = NULL;
3369         last_bg_pid = 0;
3370         job_list = NULL;
3371         last_jobid = 0;
3372
3373         /* Initialize some more globals to non-zero values */
3374         set_cwd();
3375 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3376         cmdedit_set_initial_prompt();
3377 #else
3378         PS1 = NULL;
3379 #endif
3380         PS2 = "> ";
3381
3382         /* initialize our shell local variables with the values
3383          * currently living in the environment */
3384         if (e) {
3385                 for (; *e; e++)
3386                         set_local_var(*e, 2);   /* without call putenv() */
3387         }
3388
3389         last_return_code=EXIT_SUCCESS;
3390
3391
3392         if (argv[0] && argv[0][0] == '-') {
3393                 debug_printf("\nsourcing /etc/profile\n");
3394                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3395                         mark_open(fileno(input));
3396                         parse_file_outer(input);
3397                         mark_closed(fileno(input));
3398                         fclose(input);
3399                 }
3400         }
3401         input=stdin;
3402
3403         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3404                 switch (opt) {
3405                         case 'c':
3406                                 {
3407                                         global_argv = argv+optind;
3408                                         global_argc = argc-optind;
3409                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3410                                         goto final_return;
3411                                 }
3412                                 break;
3413                         case 'i':
3414                                 interactive++;
3415                                 break;
3416                         case 'f':
3417                                 fake_mode++;
3418                                 break;
3419                         default:
3420 #ifndef BB_VER
3421                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3422                                                 "   or: sh -c command [args]...\n\n");
3423                                 exit(EXIT_FAILURE);
3424 #else
3425                                 show_usage();
3426 #endif
3427                 }
3428         }
3429         /* A shell is interactive if the `-i' flag was given, or if all of
3430          * the following conditions are met:
3431          *        no -c command
3432          *    no arguments remaining or the -s flag given
3433          *    standard input is a terminal
3434          *    standard output is a terminal
3435          *    Refer to Posix.2, the description of the `sh' utility. */
3436         if (argv[optind]==NULL && input==stdin &&
3437                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3438                 interactive++;
3439         }
3440
3441         debug_printf("\ninteractive=%d\n", interactive);
3442         if (interactive) {
3443                 /* Looks like they want an interactive shell */
3444 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3445                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3446                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3447 #endif
3448                 setup_job_control();
3449         }
3450
3451         if (argv[optind]==NULL) {
3452                 opt=parse_file_outer(stdin);
3453                 goto final_return;
3454         }
3455
3456         debug_printf("\nrunning script '%s'\n", argv[optind]);
3457         global_argv = argv+optind;
3458         global_argc = argc-optind;
3459         input = xfopen(argv[optind], "r");
3460         opt = parse_file_outer(input);
3461
3462 #ifdef CONFIG_FEATURE_CLEAN_UP
3463         fclose(input);
3464         if (cwd && cwd != unknown)
3465                 free((char*)cwd);
3466         {
3467                 struct variables *cur, *tmp;
3468                 for(cur = top_vars; cur; cur = tmp) {
3469                         tmp = cur->next;
3470                         if (!cur->flg_read_only) {
3471                                 free(cur->name);
3472                                 free(cur->value);
3473                                 free(cur);
3474                         }
3475                 }
3476         }
3477 #endif
3478
3479 final_return:
3480         return(opt?opt:last_return_code);
3481 }
3482 #endif
3483
3484 static char *insert_var_value(char *inp)
3485 {
3486         int res_str_len = 0;
3487         int len;
3488         int done = 0;
3489         char *p, *p1, *res_str = NULL;
3490
3491         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3492                 if (p != inp) {
3493                         len = p - inp;
3494                         res_str = xrealloc(res_str, (res_str_len + len));
3495                         strncpy((res_str + res_str_len), inp, len);
3496                         res_str_len += len;
3497                 }
3498                 inp = ++p;
3499                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3500                 *p = '\0';
3501                 if ((p1 = lookup_param(inp))) {
3502                         len = res_str_len + strlen(p1);
3503                         res_str = xrealloc(res_str, (1 + len));
3504                         strcpy((res_str + res_str_len), p1);
3505                         res_str_len = len;
3506                 }
3507                 *p = SPECIAL_VAR_SYMBOL;
3508                 inp = ++p;
3509                 done = 1;
3510         }
3511         if (done) {
3512                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3513                 strcpy((res_str + res_str_len), inp);
3514                 while ((p = strchr(res_str, '\n'))) {
3515                         *p = ' ';
3516                 }
3517         }
3518         return (res_str == NULL) ? inp : res_str;
3519 }
3520
3521 static char **make_list_in(char **inp, char *name)
3522 {
3523         int len, i;
3524         int name_len = strlen(name);
3525         int n = 0;
3526         char **list;
3527         char *p1, *p2, *p3;
3528
3529         /* create list of variable values */
3530         list = xmalloc(sizeof(*list));
3531         for (i = 0; inp[i]; i++) {
3532                 p3 = insert_var_value(inp[i]);
3533                 p1 = p3;
3534                 while (*p1) {
3535                         if ((*p1 == ' ')) {
3536                                 p1++;
3537                                 continue;
3538                         }
3539                         if ((p2 = strchr(p1, ' '))) {
3540                                 len = p2 - p1;
3541                         } else {
3542                                 len = strlen(p1);
3543                                 p2 = p1 + len;
3544                         }
3545                         /* we use n + 2 in realloc for list,because we add
3546                          * new element and then we will add NULL element */
3547                         list = xrealloc(list, sizeof(*list) * (n + 2));
3548                         list[n] = xmalloc(2 + name_len + len);
3549                         strcpy(list[n], name);
3550                         strcat(list[n], "=");
3551                         strncat(list[n], p1, len);
3552                         list[n++][name_len + len + 1] = '\0';
3553                         p1 = p2;
3554                 }
3555                 if (p3 != inp[i]) free(p3);
3556         }
3557         list[n] = NULL;
3558         return list;
3559 }
3560
3561 /* Make new string for parser */
3562 static char * make_string(char ** inp)
3563 {
3564         char *p;
3565         char *str = NULL;
3566         int n;
3567         int len = 2;
3568
3569         for (n = 0; inp[n]; n++) {
3570                 p = insert_var_value(inp[n]);
3571                 str = xrealloc(str, (len + strlen(p)));
3572                 if (n) {
3573                         strcat(str, " ");
3574                 } else {
3575                         *str = '\0';
3576                 }
3577                 strcat(str, p);
3578                 len = strlen(str) + 3;
3579                 if (p != inp[n]) free(p);
3580         }
3581         len = strlen(str);
3582         *(str + len) = '\n';
3583         *(str + len + 1) = '\0';
3584         return str;
3585 }
3586
3587 #endif /* CFG_HUSH_PARSER */
3588 /****************************************************************************/