common/hush.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      simple_itoa() was lifted from boa-0.93.15
  22  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  23  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  24  *        and many builtins derived from contributions by Erik Andersen
  25  *      miscellaneous bugfixes from Matt Kraai
  26  *
  27  * There are two big (and related) architecture differences between
  28  * this parser and the lash parser.  One is that this version is
  29  * actually designed from the ground up to understand nearly all
  30  * of the Bourne grammar.  The second, consequential change is that
  31  * the parser and input reader have been turned inside out.  Now,
  32  * the parser is in control, and asks for input as needed.  The old
  33  * way had the input reader in control, and it asked for parsing to
  34  * take place as needed.  The new way makes it much easier to properly
  35  * handle the recursion implicit in the various substitutions, especially
  36  * across continuation lines.
  37  *
  38  * Bash grammar not implemented: (how many of these were in original sh?)
  39  *      $@ (those sure look like weird quoting rules)
  40  *      $_
  41  *      ! negation operator for pipes
  42  *      &> and >& redirection of stdout+stderr
  43  *      Brace Expansion
  44  *      Tilde Expansion
  45  *      fancy forms of Parameter Expansion
  46  *      aliases
  47  *      Arithmetic Expansion
  48  *      <(list) and >(list) Process Substitution
  49  *      reserved words: case, esac, select, function
  50  *      Here Documents ( << word )
  51  *      Functions
  52  * Major bugs:
  53  *      job handling woefully incomplete and buggy
  54  *      reserved word execution woefully incomplete and buggy
  55  * to-do:
  56  *      port selected bugfixes from post-0.49 busybox lash - done?
  57  *      finish implementing reserved words: for, while, until, do, done
  58  *      change { and } from special chars to reserved words
  59  *      builtins: break, continue, eval, return, set, trap, ulimit
  60  *      test magic exec
  61  *      handle children going into background
  62  *      clean up recognition of null pipes
  63  *      check setting of global_argc and global_argv
  64  *      control-C handling, probably with longjmp
  65  *      follow IFS rules more precisely, including update semantics
  66  *      figure out what to do with backslash-newline
  67  *      explain why we use signal instead of sigaction
  68  *      propagate syntax errors, die on resource errors?
  69  *      continuation lines, both explicit and implicit - done?
  70  *      memory leak finding and plugging - done?
  71  *      more testing, especially quoting rules and redirection
  72  *      document how quoting rules not precisely followed for variable assignments
  73  *      maybe change map[] to use 2-bit entries
  74  *      (eventually) remove all the printf's
  75  *
  76  * This program is free software; you can redistribute it and/or modify
  77  * it under the terms of the GNU General Public License as published by
  78  * the Free Software Foundation; either version 2 of the License, or
  79  * (at your option) any later version.
  80  *
  81  * This program is distributed in the hope that it will be useful,
  82  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  83  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  84  * General Public License for more details.
  85  *
  86  * You should have received a copy of the GNU General Public License
  87  * along with this program; if not, write to the Free Software
  88  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  89  */
  90 #define __U_BOOT__
  91 #ifdef __U_BOOT__
  92 #include <malloc.h>         /* malloc, free, realloc*/
  93 #include <linux/ctype.h>    /* isalpha, isdigit */
  94 #include <common.h>        /* readline */
  95 #include <hush.h>
  96 #include <command.h>        /* find_cmd */
  97 /*cmd_boot.c*/
  98 extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);      /* do_bootd */
  99 #endif
 100 #ifdef CFG_HUSH_PARSER
 101 #ifndef __U_BOOT__
 102 #include <ctype.h>     /* isalpha, isdigit */
 103 #include <unistd.h>    /* getpid */
 104 #include <stdlib.h>    /* getenv, atoi */
 105 #include <string.h>    /* strchr */
 106 #include <stdio.h>     /* popen etc. */
 107 #include <glob.h>      /* glob, of course */
 108 #include <stdarg.h>    /* va_list */
 109 #include <errno.h>
 110 #include <fcntl.h>
 111 #include <getopt.h>    /* should be pretty obvious */
 112
 113 #include <sys/stat.h>  /* ulimit */
 114 #include <sys/types.h>
 115 #include <sys/wait.h>
 116 #include <signal.h>
 117
 118 /* #include <dmalloc.h> */
 119 /* #define DEBUG_SHELL */
 120
 121 #if 1
 122 #include "busybox.h"
 123 #include "cmdedit.h"
 124 #else
 125 #define applet_name "hush"
 126 #include "standalone.h"
 127 #define hush_main main
 128 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 129 #define BB_BANNER
 130 #endif
 131 #endif
 132 #define SPECIAL_VAR_SYMBOL 03
 133 #ifndef __U_BOOT__
 134 #define FLAG_EXIT_FROM_LOOP 1
 135 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 136 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 137
 138 #endif
 139
 140 #ifdef __U_BOOT__
 141 DECLARE_GLOBAL_DATA_PTR;
 142
 143 #define EXIT_SUCCESS 0
 144 #define EOF -1
 145 #define syntax() syntax_err()
 146 #define xstrdup strdup
 147 #define error_msg printf
 148 #else
 149 typedef enum {
 150         REDIRECT_INPUT     = 1,
 151         REDIRECT_OVERWRITE = 2,
 152         REDIRECT_APPEND    = 3,
 153         REDIRECT_HEREIS    = 4,
 154         REDIRECT_IO        = 5
 155 } redir_type;
 156
 157 /* The descrip member of this structure is only used to make debugging
 158  * output pretty */
 159 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 160         { 0,                         0, "()" },
 161         { O_RDONLY,                  0, "<"  },
 162         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 163         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 164         { O_RDONLY,                 -1, "<<" },
 165         { O_RDWR,                    1, "<>" }
 166 };
 167 #endif
 168
 169 typedef enum {
 170         PIPE_SEQ = 1,
 171         PIPE_AND = 2,
 172         PIPE_OR  = 3,
 173         PIPE_BG  = 4,
 174 } pipe_style;
 175
 176 /* might eventually control execution */
 177 typedef enum {
 178         RES_NONE  = 0,
 179         RES_IF    = 1,
 180         RES_THEN  = 2,
 181         RES_ELIF  = 3,
 182         RES_ELSE  = 4,
 183         RES_FI    = 5,
 184         RES_FOR   = 6,
 185         RES_WHILE = 7,
 186         RES_UNTIL = 8,
 187         RES_DO    = 9,
 188         RES_DONE  = 10,
 189         RES_XXXX  = 11,
 190         RES_IN    = 12,
 191         RES_SNTX  = 13
 192 } reserved_style;
 193 #define FLAG_END   (1<<RES_NONE)
 194 #define FLAG_IF    (1<<RES_IF)
 195 #define FLAG_THEN  (1<<RES_THEN)
 196 #define FLAG_ELIF  (1<<RES_ELIF)
 197 #define FLAG_ELSE  (1<<RES_ELSE)
 198 #define FLAG_FI    (1<<RES_FI)
 199 #define FLAG_FOR   (1<<RES_FOR)
 200 #define FLAG_WHILE (1<<RES_WHILE)
 201 #define FLAG_UNTIL (1<<RES_UNTIL)
 202 #define FLAG_DO    (1<<RES_DO)
 203 #define FLAG_DONE  (1<<RES_DONE)
 204 #define FLAG_IN    (1<<RES_IN)
 205 #define FLAG_START (1<<RES_XXXX)
 206
 207 /* This holds pointers to the various results of parsing */
 208 struct p_context {
 209         struct child_prog *child;
 210         struct pipe *list_head;
 211         struct pipe *pipe;
 212 #ifndef __U_BOOT__
 213         struct redir_struct *pending_redirect;
 214 #endif
 215         reserved_style w;
 216         int old_flag;                           /* for figuring out valid reserved words */
 217         struct p_context *stack;
 218         int type;                       /* define type of parser : ";$" common or special symbol */
 219         /* How about quoting status? */
 220 };
 221
 222 #ifndef __U_BOOT__
 223 struct redir_struct {
 224         redir_type type;                        /* type of redirection */
 225         int fd;                                         /* file descriptor being redirected */
 226         int dup;                                        /* -1, or file descriptor being duplicated */
 227         struct redir_struct *next;      /* pointer to the next redirect in the list */
 228         glob_t word;                            /* *word.gl_pathv is the filename */
 229 };
 230 #endif
 231
 232 struct child_prog {
 233 #ifndef __U_BOOT__
 234         pid_t pid;                                      /* 0 if exited */
 235 #endif
 236         char **argv;                            /* program name and arguments */
 237 #ifdef __U_BOOT__
 238         int    argc;                            /* number of program arguments */
 239 #endif
 240         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 241 #ifndef __U_BOOT__
 242         int subshell;                           /* flag, non-zero if group must be forked */
 243         struct redir_struct *redirects; /* I/O redirections */
 244         glob_t glob_result;                     /* result of parameter globbing */
 245         int is_stopped;                         /* is the program currently running? */
 246         struct pipe *family;            /* pointer back to the child's parent pipe */
 247 #endif
 248         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 249         int type;
 250 };
 251
 252 struct pipe {
 253 #ifndef __U_BOOT__
 254         int jobid;                                      /* job number */
 255 #endif
 256         int num_progs;                          /* total number of programs in job */
 257 #ifndef __U_BOOT__
 258         int running_progs;                      /* number of programs running */
 259         char *text;                                     /* name of job */
 260         char *cmdbuf;                           /* buffer various argv's point into */
 261         pid_t pgrp;                                     /* process group ID for the job */
 262 #endif
 263         struct child_prog *progs;       /* array of commands in pipe */
 264         struct pipe *next;                      /* to track background commands */
 265 #ifndef __U_BOOT__
 266         int stopped_progs;                      /* number of programs alive, but stopped */
 267         int job_context;                        /* bitmask defining current context */
 268 #endif
 269         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 270         reserved_style r_mode;          /* supports if, for, while, until */
 271 };
 272
 273 #ifndef __U_BOOT__
 274 struct close_me {
 275         int fd;
 276         struct close_me *next;
 277 };
 278 #endif
 279
 280 struct variables {
 281         char *name;
 282         char *value;
 283         int flg_export;
 284         int flg_read_only;
 285         struct variables *next;
 286 };
 287
 288 /* globals, connect us to the outside world
 289  * the first three support $?, $#, and $1 */
 290 #ifndef __U_BOOT__
 291 char **global_argv;
 292 unsigned int global_argc;
 293 #endif
 294 unsigned int last_return_code;
 295 int nesting_level;
 296 #ifndef __U_BOOT__
 297 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 298 #endif
 299
 300 /* "globals" within this file */
 301 static uchar *ifs;
 302 static char map[256];
 303 #ifndef __U_BOOT__
 304 static int fake_mode;
 305 static int interactive;
 306 static struct close_me *close_me_head;
 307 static const char *cwd;
 308 static struct pipe *job_list;
 309 static unsigned int last_bg_pid;
 310 static unsigned int last_jobid;
 311 static unsigned int shell_terminal;
 312 static char *PS1;
 313 static char *PS2;
 314 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 315 struct variables *top_vars = &shell_ver;
 316 #else
 317 static int flag_repeat = 0;
 318 static int do_repeat = 0;
 319 static struct variables *top_vars = NULL ;
 320 #endif /*__U_BOOT__ */
 321
 322 #define B_CHUNK (100)
 323 #define B_NOSPAC 1
 324
 325 typedef struct {
 326         char *data;
 327         int length;
 328         int maxlen;
 329         int quote;
 330         int nonnull;
 331 } o_string;
 332 #define NULL_O_STRING {NULL,0,0,0,0}
 333 /* used for initialization:
 334         o_string foo = NULL_O_STRING; */
 335
 336 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 337  * available?  Where is it documented? */
 338 struct in_str {
 339         const char *p;
 340 #ifndef __U_BOOT__
 341         char peek_buf[2];
 342 #endif
 343         int __promptme;
 344         int promptmode;
 345 #ifndef __U_BOOT__
 346         FILE *file;
 347 #endif
 348         int (*get) (struct in_str *);
 349         int (*peek) (struct in_str *);
 350 };
 351 #define b_getch(input) ((input)->get(input))
 352 #define b_peek(input) ((input)->peek(input))
 353
 354 #ifndef __U_BOOT__
 355 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 356
 357 struct built_in_command {
 358         char *cmd;                                      /* name */
 359         char *descr;                            /* description */
 360         int (*function) (struct child_prog *);  /* function ptr */
 361 };
 362 #endif
 363
 364 /* This should be in utility.c */
 365 #ifdef DEBUG_SHELL
 366 #ifndef __U_BOOT__
 367 static void debug_printf(const char *format, ...)
 368 {
 369         va_list args;
 370         va_start(args, format);
 371         vfprintf(stderr, format, args);
 372         va_end(args);
 373 }
 374 #else
 375 #define debug_printf printf             /* U-Boot debug flag */
 376 #endif
 377 #else
 378 static inline void debug_printf(const char *format, ...) { }
 379 #endif
 380 #define final_printf debug_printf
 381
 382 #ifdef __U_BOOT__
 383 static void syntax_err(void) {
 384          printf("syntax error\n");
 385 }
 386 #else
 387 static void __syntax(char *file, int line) {
 388         error_msg("syntax error %s:%d", file, line);
 389 }
 390 #define syntax() __syntax(__FILE__, __LINE__)
 391 #endif
 392
 393 #ifdef __U_BOOT__
 394 static void *xmalloc(size_t size);
 395 static void *xrealloc(void *ptr, size_t size);
 396 #else
 397 /* Index of subroutines: */
 398 /*   function prototypes for builtins */
 399 static int builtin_cd(struct child_prog *child);
 400 static int builtin_env(struct child_prog *child);
 401 static int builtin_eval(struct child_prog *child);
 402 static int builtin_exec(struct child_prog *child);
 403 static int builtin_exit(struct child_prog *child);
 404 static int builtin_export(struct child_prog *child);
 405 static int builtin_fg_bg(struct child_prog *child);
 406 static int builtin_help(struct child_prog *child);
 407 static int builtin_jobs(struct child_prog *child);
 408 static int builtin_pwd(struct child_prog *child);
 409 static int builtin_read(struct child_prog *child);
 410 static int builtin_set(struct child_prog *child);
 411 static int builtin_shift(struct child_prog *child);
 412 static int builtin_source(struct child_prog *child);
 413 static int builtin_umask(struct child_prog *child);
 414 static int builtin_unset(struct child_prog *child);
 415 static int builtin_not_written(struct child_prog *child);
 416 #endif
 417 /*   o_string manipulation: */
 418 static int b_check_space(o_string *o, int len);
 419 static int b_addchr(o_string *o, int ch);
 420 static void b_reset(o_string *o);
 421 static int b_addqchr(o_string *o, int ch, int quote);
 422 #ifndef __U_BOOT__
 423 static int b_adduint(o_string *o, unsigned int i);
 424 #endif
 425 /*  in_str manipulations: */
 426 static int static_get(struct in_str *i);
 427 static int static_peek(struct in_str *i);
 428 static int file_get(struct in_str *i);
 429 static int file_peek(struct in_str *i);
 430 #ifndef __U_BOOT__
 431 static void setup_file_in_str(struct in_str *i, FILE *f);
 432 #else
 433 static void setup_file_in_str(struct in_str *i);
 434 #endif
 435 static void setup_string_in_str(struct in_str *i, const char *s);
 436 #ifndef __U_BOOT__
 437 /*  close_me manipulations: */
 438 static void mark_open(int fd);
 439 static void mark_closed(int fd);
 440 static void close_all(void);
 441 #endif
 442 /*  "run" the final data structures: */
 443 static char *indenter(int i);
 444 static int free_pipe_list(struct pipe *head, int indent);
 445 static int free_pipe(struct pipe *pi, int indent);
 446 /*  really run the final data structures: */
 447 #ifndef __U_BOOT__
 448 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 449 #endif
 450 static int run_list_real(struct pipe *pi);
 451 #ifndef __U_BOOT__
 452 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 453 #endif
 454 static int run_pipe_real(struct pipe *pi);
 455 /*   extended glob support: */
 456 #ifndef __U_BOOT__
 457 static int globhack(const char *src, int flags, glob_t *pglob);
 458 static int glob_needed(const char *s);
 459 static int xglob(o_string *dest, int flags, glob_t *pglob);
 460 #endif
 461 /*   variable assignment: */
 462 static int is_assignment(const char *s);
 463 /*   data structure manipulation: */
 464 #ifndef __U_BOOT__
 465 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 466 #endif
 467 static void initialize_context(struct p_context *ctx);
 468 static int done_word(o_string *dest, struct p_context *ctx);
 469 static int done_command(struct p_context *ctx);
 470 static int done_pipe(struct p_context *ctx, pipe_style type);
 471 /*   primary string parsing: */
 472 #ifndef __U_BOOT__
 473 static int redirect_dup_num(struct in_str *input);
 474 static int redirect_opt_num(o_string *o);
 475 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 476 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 477 #endif
 478 static char *lookup_param(char *src);
 479 static char *make_string(char **inp);
 480 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 481 #ifndef __U_BOOT__
 482 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 483 #endif
 484 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 485 /*   setup: */
 486 static int parse_stream_outer(struct in_str *inp, int flag);
 487 #ifndef __U_BOOT__
 488 static int parse_string_outer(const char *s, int flag);
 489 static int parse_file_outer(FILE *f);
 490 #endif
 491 #ifndef __U_BOOT__
 492 /*   job management: */
 493 static int checkjobs(struct pipe* fg_pipe);
 494 static void insert_bg_job(struct pipe *pi);
 495 static void remove_bg_job(struct pipe *pi);
 496 #endif
 497 /*     local variable support */
 498 static char **make_list_in(char **inp, char *name);
 499 static char *insert_var_value(char *inp);
 500 static char *get_local_var(const char *var);
 501 #ifndef __U_BOOT__
 502 static void  unset_local_var(const char *name);
 503 #endif
 504 static int set_local_var(const char *s, int flg_export);
 505
 506 #ifndef __U_BOOT__
 507 /* Table of built-in functions.  They can be forked or not, depending on
 508  * context: within pipes, they fork.  As simple commands, they do not.
 509  * When used in non-forking context, they can change global variables
 510  * in the parent shell process.  If forked, of course they can not.
 511  * For example, 'unset foo | whatever' will parse and run, but foo will
 512  * still be set at the end. */
 513 static struct built_in_command bltins[] = {
 514         {"bg", "Resume a job in the background", builtin_fg_bg},
 515         {"break", "Exit for, while or until loop", builtin_not_written},
 516         {"cd", "Change working directory", builtin_cd},
 517         {"continue", "Continue for, while or until loop", builtin_not_written},
 518         {"env", "Print all environment variables", builtin_env},
 519         {"eval", "Construct and run shell command", builtin_eval},
 520         {"exec", "Exec command, replacing this shell with the exec'd process",
 521                 builtin_exec},
 522         {"exit", "Exit from shell()", builtin_exit},
 523         {"export", "Set environment variable", builtin_export},
 524         {"fg", "Bring job into the foreground", builtin_fg_bg},
 525         {"jobs", "Lists the active jobs", builtin_jobs},
 526         {"pwd", "Print current directory", builtin_pwd},
 527         {"read", "Input environment variable", builtin_read},
 528         {"return", "Return from a function", builtin_not_written},
 529         {"set", "Set/unset shell local variables", builtin_set},
 530         {"shift", "Shift positional parameters", builtin_shift},
 531         {"trap", "Trap signals", builtin_not_written},
 532         {"ulimit","Controls resource limits", builtin_not_written},
 533         {"umask","Sets file creation mask", builtin_umask},
 534         {"unset", "Unset environment variable", builtin_unset},
 535         {".", "Source-in and run commands in a file", builtin_source},
 536         {"help", "List shell built-in commands", builtin_help},
 537         {NULL, NULL, NULL}
 538 };
 539
 540 static const char *set_cwd(void)
 541 {
 542         if(cwd==unknown)
 543                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 544         cwd = xgetcwd((char *)cwd);
 545         if (!cwd)
 546                 cwd = unknown;
 547         return cwd;
 548 }
 549
 550 /* built-in 'eval' handler */
 551 static int builtin_eval(struct child_prog *child)
 552 {
 553         char *str = NULL;
 554         int rcode = EXIT_SUCCESS;
 555
 556         if (child->argv[1]) {
 557                 str = make_string(child->argv + 1);
 558                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 559                                         FLAG_PARSE_SEMICOLON);
 560                 free(str);
 561                 rcode = last_return_code;
 562         }
 563         return rcode;
 564 }
 565
 566 /* built-in 'cd <path>' handler */
 567 static int builtin_cd(struct child_prog *child)
 568 {
 569         char *newdir;
 570         if (child->argv[1] == NULL)
 571                 newdir = getenv("HOME");
 572         else
 573                 newdir = child->argv[1];
 574         if (chdir(newdir)) {
 575                 printf("cd: %s: %s\n", newdir, strerror(errno));
 576                 return EXIT_FAILURE;
 577         }
 578         set_cwd();
 579         return EXIT_SUCCESS;
 580 }
 581
 582 /* built-in 'env' handler */
 583 static int builtin_env(struct child_prog *dummy)
 584 {
 585         char **e = environ;
 586         if (e == NULL) return EXIT_FAILURE;
 587         for (; *e; e++) {
 588                 puts(*e);
 589         }
 590         return EXIT_SUCCESS;
 591 }
 592
 593 /* built-in 'exec' handler */
 594 static int builtin_exec(struct child_prog *child)
 595 {
 596         if (child->argv[1] == NULL)
 597                 return EXIT_SUCCESS;   /* Really? */
 598         child->argv++;
 599         pseudo_exec(child);
 600         /* never returns */
 601 }
 602
 603 /* built-in 'exit' handler */
 604 static int builtin_exit(struct child_prog *child)
 605 {
 606         if (child->argv[1] == NULL)
 607                 exit(last_return_code);
 608         exit (atoi(child->argv[1]));
 609 }
 610
 611 /* built-in 'export VAR=value' handler */
 612 static int builtin_export(struct child_prog *child)
 613 {
 614         int res = 0;
 615         char *name = child->argv[1];
 616
 617         if (name == NULL) {
 618                 return (builtin_env(child));
 619         }
 620
 621         name = strdup(name);
 622
 623         if(name) {
 624                 char *value = strchr(name, '=');
 625
 626                 if (!value) {
 627                         char *tmp;
 628                         /* They are exporting something without an =VALUE */
 629
 630                         value = get_local_var(name);
 631                         if (value) {
 632                                 size_t ln = strlen(name);
 633
 634                                 tmp = realloc(name, ln+strlen(value)+2);
 635                                 if(tmp==NULL)
 636                                         res = -1;
 637                                 else {
 638                                         sprintf(tmp+ln, "=%s", value);
 639                                         name = tmp;
 640                                 }
 641                         } else {
 642                                 /* bash does not return an error when trying to export
 643                                  * an undefined variable.  Do likewise. */
 644                                 res = 1;
 645                         }
 646                 }
 647         }
 648         if (res<0)
 649                 perror_msg("export");
 650         else if(res==0)
 651                 res = set_local_var(name, 1);
 652         else
 653                 res = 0;
 654         free(name);
 655         return res;
 656 }
 657
 658 /* built-in 'fg' and 'bg' handler */
 659 static int builtin_fg_bg(struct child_prog *child)
 660 {
 661         int i, jobnum;
 662         struct pipe *pi=NULL;
 663
 664         if (!interactive)
 665                 return EXIT_FAILURE;
 666         /* If they gave us no args, assume they want the last backgrounded task */
 667         if (!child->argv[1]) {
 668                 for (pi = job_list; pi; pi = pi->next) {
 669                         if (pi->jobid == last_jobid) {
 670                                 break;
 671                         }
 672                 }
 673                 if (!pi) {
 674                         error_msg("%s: no current job", child->argv[0]);
 675                         return EXIT_FAILURE;
 676                 }
 677         } else {
 678                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 679                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 680                         return EXIT_FAILURE;
 681                 }
 682                 for (pi = job_list; pi; pi = pi->next) {
 683                         if (pi->jobid == jobnum) {
 684                                 break;
 685                         }
 686                 }
 687                 if (!pi) {
 688                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 689                         return EXIT_FAILURE;
 690                 }
 691         }
 692
 693         if (*child->argv[0] == 'f') {
 694                 /* Put the job into the foreground.  */
 695                 tcsetpgrp(shell_terminal, pi->pgrp);
 696         }
 697
 698         /* Restart the processes in the job */
 699         for (i = 0; i < pi->num_progs; i++)
 700                 pi->progs[i].is_stopped = 0;
 701
 702         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 703                 if (i == ESRCH) {
 704                         remove_bg_job(pi);
 705                 } else {
 706                         perror_msg("kill (SIGCONT)");
 707                 }
 708         }
 709
 710         pi->stopped_progs = 0;
 711         return EXIT_SUCCESS;
 712 }
 713
 714 /* built-in 'help' handler */
 715 static int builtin_help(struct child_prog *dummy)
 716 {
 717         struct built_in_command *x;
 718
 719         printf("\nBuilt-in commands:\n");
 720         printf("-------------------\n");
 721         for (x = bltins; x->cmd; x++) {
 722                 if (x->descr==NULL)
 723                         continue;
 724                 printf("%s\t%s\n", x->cmd, x->descr);
 725         }
 726         printf("\n\n");
 727         return EXIT_SUCCESS;
 728 }
 729
 730 /* built-in 'jobs' handler */
 731 static int builtin_jobs(struct child_prog *child)
 732 {
 733         struct pipe *job;
 734         char *status_string;
 735
 736         for (job = job_list; job; job = job->next) {
 737                 if (job->running_progs == job->stopped_progs)
 738                         status_string = "Stopped";
 739                 else
 740                         status_string = "Running";
 741
 742                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 743         }
 744         return EXIT_SUCCESS;
 745 }
 746
 747
 748 /* built-in 'pwd' handler */
 749 static int builtin_pwd(struct child_prog *dummy)
 750 {
 751         puts(set_cwd());
 752         return EXIT_SUCCESS;
 753 }
 754
 755 /* built-in 'read VAR' handler */
 756 static int builtin_read(struct child_prog *child)
 757 {
 758         int res;
 759
 760         if (child->argv[1]) {
 761                 char string[BUFSIZ];
 762                 char *var = 0;
 763
 764                 string[0] = 0;  /* In case stdin has only EOF */
 765                 /* read string */
 766                 fgets(string, sizeof(string), stdin);
 767                 chomp(string);
 768                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 769                 if(var) {
 770                         sprintf(var, "%s=%s", child->argv[1], string);
 771                         res = set_local_var(var, 0);
 772                 } else
 773                         res = -1;
 774                 if (res)
 775                         fprintf(stderr, "read: %m\n");
 776                 free(var);      /* So not move up to avoid breaking errno */
 777                 return res;
 778         } else {
 779                 do res=getchar(); while(res!='\n' && res!=EOF);
 780                 return 0;
 781         }
 782 }
 783
 784 /* built-in 'set VAR=value' handler */
 785 static int builtin_set(struct child_prog *child)
 786 {
 787         char *temp = child->argv[1];
 788         struct variables *e;
 789
 790         if (temp == NULL)
 791                 for(e = top_vars; e; e=e->next)
 792                         printf("%s=%s\n", e->name, e->value);
 793         else
 794                 set_local_var(temp, 0);
 795
 796                 return EXIT_SUCCESS;
 797 }
 798
 799
 800 /* Built-in 'shift' handler */
 801 static int builtin_shift(struct child_prog *child)
 802 {
 803         int n=1;
 804         if (child->argv[1]) {
 805                 n=atoi(child->argv[1]);
 806         }
 807         if (n>=0 && n<global_argc) {
 808                 /* XXX This probably breaks $0 */
 809                 global_argc -= n;
 810                 global_argv += n;
 811                 return EXIT_SUCCESS;
 812         } else {
 813                 return EXIT_FAILURE;
 814         }
 815 }
 816
 817 /* Built-in '.' handler (read-in and execute commands from file) */
 818 static int builtin_source(struct child_prog *child)
 819 {
 820         FILE *input;
 821         int status;
 822
 823         if (child->argv[1] == NULL)
 824                 return EXIT_FAILURE;
 825
 826         /* XXX search through $PATH is missing */
 827         input = fopen(child->argv[1], "r");
 828         if (!input) {
 829                 error_msg("Couldn't open file '%s'", child->argv[1]);
 830                 return EXIT_FAILURE;
 831         }
 832
 833         /* Now run the file */
 834         /* XXX argv and argc are broken; need to save old global_argv
 835          * (pointer only is OK!) on this stack frame,
 836          * set global_argv=child->argv+1, recurse, and restore. */
 837         mark_open(fileno(input));
 838         status = parse_file_outer(input);
 839         mark_closed(fileno(input));
 840         fclose(input);
 841         return (status);
 842 }
 843
 844 static int builtin_umask(struct child_prog *child)
 845 {
 846         mode_t new_umask;
 847         const char *arg = child->argv[1];
 848         char *end;
 849         if (arg) {
 850                 new_umask=strtoul(arg, &end, 8);
 851                 if (*end!='\0' || end == arg) {
 852                         return EXIT_FAILURE;
 853                 }
 854         } else {
 855                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 856         }
 857         umask(new_umask);
 858         return EXIT_SUCCESS;
 859 }
 860
 861 /* built-in 'unset VAR' handler */
 862 static int builtin_unset(struct child_prog *child)
 863 {
 864         /* bash returned already true */
 865         unset_local_var(child->argv[1]);
 866         return EXIT_SUCCESS;
 867 }
 868
 869 static int builtin_not_written(struct child_prog *child)
 870 {
 871         printf("builtin_%s not written\n",child->argv[0]);
 872         return EXIT_FAILURE;
 873 }
 874 #endif
 875
 876 static int b_check_space(o_string *o, int len)
 877 {
 878         /* It would be easy to drop a more restrictive policy
 879          * in here, such as setting a maximum string length */
 880         if (o->length + len > o->maxlen) {
 881                 char *old_data = o->data;
 882                 /* assert (data == NULL || o->maxlen != 0); */
 883                 o->maxlen += max(2*len, B_CHUNK);
 884                 o->data = realloc(o->data, 1 + o->maxlen);
 885                 if (o->data == NULL) {
 886                         free(old_data);
 887                 }
 888         }
 889         return o->data == NULL;
 890 }
 891
 892 static int b_addchr(o_string *o, int ch)
 893 {
 894         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 895         if (b_check_space(o, 1)) return B_NOSPAC;
 896         o->data[o->length] = ch;
 897         o->length++;
 898         o->data[o->length] = '\0';
 899         return 0;
 900 }
 901
 902 static void b_reset(o_string *o)
 903 {
 904         o->length = 0;
 905         o->nonnull = 0;
 906         if (o->data != NULL) *o->data = '\0';
 907 }
 908
 909 static void b_free(o_string *o)
 910 {
 911         b_reset(o);
 912         free(o->data);
 913         o->data = NULL;
 914         o->maxlen = 0;
 915 }
 916
 917 /* My analysis of quoting semantics tells me that state information
 918  * is associated with a destination, not a source.
 919  */
 920 static int b_addqchr(o_string *o, int ch, int quote)
 921 {
 922         if (quote && strchr("*?[\\",ch)) {
 923                 int rc;
 924                 rc = b_addchr(o, '\\');
 925                 if (rc) return rc;
 926         }
 927         return b_addchr(o, ch);
 928 }
 929
 930 /* belongs in utility.c */
 931 char *simple_itoa(unsigned int i)
 932 {
 933         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 934         static char local[22];
 935         char *p = &local[21];
 936         *p-- = '\0';
 937         do {
 938                 *p-- = '0' + i % 10;
 939                 i /= 10;
 940         } while (i > 0);
 941         return p + 1;
 942 }
 943
 944 #ifndef __U_BOOT__
 945 static int b_adduint(o_string *o, unsigned int i)
 946 {
 947         int r;
 948         char *p = simple_itoa(i);
 949         /* no escape checking necessary */
 950         do r=b_addchr(o, *p++); while (r==0 && *p);
 951         return r;
 952 }
 953 #endif
 954
 955 static int static_get(struct in_str *i)
 956 {
 957         int ch=*i->p++;
 958         if (ch=='\0') return EOF;
 959         return ch;
 960 }
 961
 962 static int static_peek(struct in_str *i)
 963 {
 964         return *i->p;
 965 }
 966
 967 #ifndef __U_BOOT__
 968 static inline void cmdedit_set_initial_prompt(void)
 969 {
 970 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 971         PS1 = NULL;
 972 #else
 973         PS1 = getenv("PS1");
 974         if(PS1==0)
 975                 PS1 = "\\w \\$ ";
 976 #endif
 977 }
 978
 979 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 980 {
 981         debug_printf("setup_prompt_string %d ",promptmode);
 982 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 983         /* Set up the prompt */
 984         if (promptmode == 1) {
 985                 free(PS1);
 986                 PS1=xmalloc(strlen(cwd)+4);
 987                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 988                 *prompt_str = PS1;
 989         } else {
 990                 *prompt_str = PS2;
 991         }
 992 #else
 993         *prompt_str = (promptmode==1)? PS1 : PS2;
 994 #endif
 995         debug_printf("result %s\n",*prompt_str);
 996 }
 997 #endif
 998
 999 static void get_user_input(struct in_str *i)
1000 {
1001 #ifndef __U_BOOT__
1002         char *prompt_str;
1003         static char the_command[BUFSIZ];
1004
1005         setup_prompt_string(i->promptmode, &prompt_str);
1006 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1007         /*
1008          ** enable command line editing only while a command line
1009          ** is actually being read; otherwise, we'll end up bequeathing
1010          ** atexit() handlers and other unwanted stuff to our
1011          ** child processes (rob@sysgo.de)
1012          */
1013         cmdedit_read_input(prompt_str, the_command);
1014 #else
1015         fputs(prompt_str, stdout);
1016         fflush(stdout);
1017         the_command[0]=fgetc(i->file);
1018         the_command[1]='\0';
1019 #endif
1020         fflush(stdout);
1021         i->p = the_command;
1022 #else
1023         extern char console_buffer[CFG_CBSIZE];
1024         int n;
1025         static char the_command[CFG_CBSIZE];
1026
1027 #ifdef CONFIG_BOOT_RETRY_TIME
1028 #  ifdef CONFIG_RESET_TO_RETRY
1029         extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1030 #  else
1031 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1032 #  endif
1033         reset_cmd_timeout();
1034 #endif
1035         i->__promptme = 1;
1036         if (i->promptmode == 1) {
1037                 n = readline(CFG_PROMPT);
1038         } else {
1039                 n = readline(CFG_PROMPT_HUSH_PS2);
1040         }
1041 #ifdef CONFIG_BOOT_RETRY_TIME
1042         if (n == -2) {
1043           puts("\nTimeout waiting for command\n");
1044 #  ifdef CONFIG_RESET_TO_RETRY
1045           do_reset(NULL, 0, 0, NULL);
1046 #  else
1047 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1048 #  endif
1049         }
1050 #endif
1051         if (n == -1 ) {
1052                 flag_repeat = 0;
1053                 i->__promptme = 0;
1054         }
1055         n = strlen(console_buffer);
1056         console_buffer[n] = '\n';
1057         console_buffer[n+1]= '\0';
1058         if (had_ctrlc()) flag_repeat = 0;
1059         clear_ctrlc();
1060         do_repeat = 0;
1061         if (i->promptmode == 1) {
1062                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1063                         strcpy(the_command,console_buffer);
1064                 }
1065                 else {
1066                         if (console_buffer[0] != '\n') {
1067                                 strcpy(the_command,console_buffer);
1068                                 flag_repeat = 1;
1069                         }
1070                         else {
1071                                 do_repeat = 1;
1072                         }
1073                 }
1074                 i->p = the_command;
1075         }
1076         else {
1077                 if (console_buffer[0] != '\n') {
1078                         if (strlen(the_command) + strlen(console_buffer)
1079                             < CFG_CBSIZE) {
1080                                 n = strlen(the_command);
1081                                 the_command[n-1] = ' ';
1082                                 strcpy(&the_command[n],console_buffer);
1083                         }
1084                         else {
1085                                 the_command[0] = '\n';
1086                                 the_command[1] = '\0';
1087                                 flag_repeat = 0;
1088                         }
1089                 }
1090                 if (i->__promptme == 0) {
1091                         the_command[0] = '\n';
1092                         the_command[1] = '\0';
1093                 }
1094                 i->p = console_buffer;
1095         }
1096 #endif
1097 }
1098
1099 /* This is the magic location that prints prompts
1100  * and gets data back from the user */
1101 static int file_get(struct in_str *i)
1102 {
1103         int ch;
1104
1105         ch = 0;
1106         /* If there is data waiting, eat it up */
1107         if (i->p && *i->p) {
1108                 ch=*i->p++;
1109         } else {
1110                 /* need to double check i->file because we might be doing something
1111                  * more complicated by now, like sourcing or substituting. */
1112 #ifndef __U_BOOT__
1113                 if (i->__promptme && interactive && i->file == stdin) {
1114                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1115 #else
1116                         while(! i->p  || strlen(i->p)==0 ) {
1117 #endif
1118                                 get_user_input(i);
1119                         }
1120                         i->promptmode=2;
1121 #ifndef __U_BOOT__
1122                         i->__promptme = 0;
1123 #endif
1124                         if (i->p && *i->p) {
1125                                 ch=*i->p++;
1126                         }
1127 #ifndef __U_BOOT__
1128                 } else {
1129                         ch = fgetc(i->file);
1130                 }
1131
1132 #endif
1133                 debug_printf("b_getch: got a %d\n", ch);
1134         }
1135 #ifndef __U_BOOT__
1136         if (ch == '\n') i->__promptme=1;
1137 #endif
1138         return ch;
1139 }
1140
1141 /* All the callers guarantee this routine will never be
1142  * used right after a newline, so prompting is not needed.
1143  */
1144 static int file_peek(struct in_str *i)
1145 {
1146 #ifndef __U_BOOT__
1147         if (i->p && *i->p) {
1148 #endif
1149                 return *i->p;
1150 #ifndef __U_BOOT__
1151         } else {
1152                 i->peek_buf[0] = fgetc(i->file);
1153                 i->peek_buf[1] = '\0';
1154                 i->p = i->peek_buf;
1155                 debug_printf("b_peek: got a %d\n", *i->p);
1156                 return *i->p;
1157         }
1158 #endif
1159 }
1160
1161 #ifndef __U_BOOT__
1162 static void setup_file_in_str(struct in_str *i, FILE *f)
1163 #else
1164 static void setup_file_in_str(struct in_str *i)
1165 #endif
1166 {
1167         i->peek = file_peek;
1168         i->get = file_get;
1169         i->__promptme=1;
1170         i->promptmode=1;
1171 #ifndef __U_BOOT__
1172         i->file = f;
1173 #endif
1174         i->p = NULL;
1175 }
1176
1177 static void setup_string_in_str(struct in_str *i, const char *s)
1178 {
1179         i->peek = static_peek;
1180         i->get = static_get;
1181         i->__promptme=1;
1182         i->promptmode=1;
1183         i->p = s;
1184 }
1185
1186 #ifndef __U_BOOT__
1187 static void mark_open(int fd)
1188 {
1189         struct close_me *new = xmalloc(sizeof(struct close_me));
1190         new->fd = fd;
1191         new->next = close_me_head;
1192         close_me_head = new;
1193 }
1194
1195 static void mark_closed(int fd)
1196 {
1197         struct close_me *tmp;
1198         if (close_me_head == NULL || close_me_head->fd != fd)
1199                 error_msg_and_die("corrupt close_me");
1200         tmp = close_me_head;
1201         close_me_head = close_me_head->next;
1202         free(tmp);
1203 }
1204
1205 static void close_all(void)
1206 {
1207         struct close_me *c;
1208         for (c=close_me_head; c; c=c->next) {
1209                 close(c->fd);
1210         }
1211         close_me_head = NULL;
1212 }
1213
1214 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1215  * and stderr if they are redirected. */
1216 static int setup_redirects(struct child_prog *prog, int squirrel[])
1217 {
1218         int openfd, mode;
1219         struct redir_struct *redir;
1220
1221         for (redir=prog->redirects; redir; redir=redir->next) {
1222                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1223                         /* something went wrong in the parse.  Pretend it didn't happen */
1224                         continue;
1225                 }
1226                 if (redir->dup == -1) {
1227                         mode=redir_table[redir->type].mode;
1228                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1229                         if (openfd < 0) {
1230                         /* this could get lost if stderr has been redirected, but
1231                            bash and ash both lose it as well (though zsh doesn't!) */
1232                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1233                                 return 1;
1234                         }
1235                 } else {
1236                         openfd = redir->dup;
1237                 }
1238
1239                 if (openfd != redir->fd) {
1240                         if (squirrel && redir->fd < 3) {
1241                                 squirrel[redir->fd] = dup(redir->fd);
1242                         }
1243                         if (openfd == -3) {
1244                                 close(openfd);
1245                         } else {
1246                                 dup2(openfd, redir->fd);
1247                                 if (redir->dup == -1)
1248                                         close (openfd);
1249                         }
1250                 }
1251         }
1252         return 0;
1253 }
1254
1255 static void restore_redirects(int squirrel[])
1256 {
1257         int i, fd;
1258         for (i=0; i<3; i++) {
1259                 fd = squirrel[i];
1260                 if (fd != -1) {
1261                         /* No error checking.  I sure wouldn't know what
1262                          * to do with an error if I found one! */
1263                         dup2(fd, i);
1264                         close(fd);
1265                 }
1266         }
1267 }
1268
1269 /* never returns */
1270 /* XXX no exit() here.  If you don't exec, use _exit instead.
1271  * The at_exit handlers apparently confuse the calling process,
1272  * in particular stdin handling.  Not sure why? */
1273 static void pseudo_exec(struct child_prog *child)
1274 {
1275         int i, rcode;
1276         char *p;
1277         struct built_in_command *x;
1278         if (child->argv) {
1279                 for (i=0; is_assignment(child->argv[i]); i++) {
1280                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1281                         p = insert_var_value(child->argv[i]);
1282                         putenv(strdup(p));
1283                         if (p != child->argv[i]) free(p);
1284                 }
1285                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1286                                         to exit, and therefore don't need to keep data
1287                                         structures consistent for free() use. */
1288                 /* If a variable is assigned in a forest, and nobody listens,
1289                  * was it ever really set?
1290                  */
1291                 if (child->argv[0] == NULL) {
1292                         _exit(EXIT_SUCCESS);
1293                 }
1294
1295                 /*
1296                  * Check if the command matches any of the builtins.
1297                  * Depending on context, this might be redundant.  But it's
1298                  * easier to waste a few CPU cycles than it is to figure out
1299                  * if this is one of those cases.
1300                  */
1301                 for (x = bltins; x->cmd; x++) {
1302                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1303                                 debug_printf("builtin exec %s\n", child->argv[0]);
1304                                 rcode = x->function(child);
1305                                 fflush(stdout);
1306                                 _exit(rcode);
1307                         }
1308                 }
1309
1310                 /* Check if the command matches any busybox internal commands
1311                  * ("applets") here.
1312                  * FIXME: This feature is not 100% safe, since
1313                  * BusyBox is not fully reentrant, so we have no guarantee the things
1314                  * from the .bss are still zeroed, or that things from .data are still
1315                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1316                  * really dislike relying on /proc for things.  We could exec ourself
1317                  * from global_argv[0], but if we are in a chroot, we may not be able
1318                  * to find ourself... */
1319 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1320                 {
1321                         int argc_l;
1322                         char** argv_l=child->argv;
1323                         char *name = child->argv[0];
1324
1325 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1326                         /* Following discussions from November 2000 on the busybox mailing
1327                          * list, the default configuration, (without
1328                          * get_last_path_component()) lets the user force use of an
1329                          * external command by specifying the full (with slashes) filename.
1330                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1331                          * _aways_ override external commands, so if you want to run
1332                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1333                          * filesystem and is _not_ busybox.  Some systems may want this,
1334                          * most do not.  */
1335                         name = get_last_path_component(name);
1336 #endif
1337                         /* Count argc for use in a second... */
1338                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1339                         optind = 1;
1340                         debug_printf("running applet %s\n", name);
1341                         run_applet_by_name(name, argc_l, child->argv);
1342                 }
1343 #endif
1344                 debug_printf("exec of %s\n",child->argv[0]);
1345                 execvp(child->argv[0],child->argv);
1346                 perror_msg("couldn't exec: %s",child->argv[0]);
1347                 _exit(1);
1348         } else if (child->group) {
1349                 debug_printf("runtime nesting to group\n");
1350                 interactive=0;    /* crucial!!!! */
1351                 rcode = run_list_real(child->group);
1352                 /* OK to leak memory by not calling free_pipe_list,
1353                  * since this process is about to exit */
1354                 _exit(rcode);
1355         } else {
1356                 /* Can happen.  See what bash does with ">foo" by itself. */
1357                 debug_printf("trying to pseudo_exec null command\n");
1358                 _exit(EXIT_SUCCESS);
1359         }
1360 }
1361
1362 static void insert_bg_job(struct pipe *pi)
1363 {
1364         struct pipe *thejob;
1365
1366         /* Linear search for the ID of the job to use */
1367         pi->jobid = 1;
1368         for (thejob = job_list; thejob; thejob = thejob->next)
1369                 if (thejob->jobid >= pi->jobid)
1370                         pi->jobid = thejob->jobid + 1;
1371
1372         /* add thejob to the list of running jobs */
1373         if (!job_list) {
1374                 thejob = job_list = xmalloc(sizeof(*thejob));
1375         } else {
1376                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1377                 thejob->next = xmalloc(sizeof(*thejob));
1378                 thejob = thejob->next;
1379         }
1380
1381         /* physically copy the struct job */
1382         memcpy(thejob, pi, sizeof(struct pipe));
1383         thejob->next = NULL;
1384         thejob->running_progs = thejob->num_progs;
1385         thejob->stopped_progs = 0;
1386         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1387
1388         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1389         {
1390                 char *bar=thejob->text;
1391                 char **foo=pi->progs[0].argv;
1392                 while(foo && *foo) {
1393                         bar += sprintf(bar, "%s ", *foo++);
1394                 }
1395         }
1396
1397         /* we don't wait for background thejobs to return -- append it
1398            to the list of backgrounded thejobs and leave it alone */
1399         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1400         last_bg_pid = thejob->progs[0].pid;
1401         last_jobid = thejob->jobid;
1402 }
1403
1404 /* remove a backgrounded job */
1405 static void remove_bg_job(struct pipe *pi)
1406 {
1407         struct pipe *prev_pipe;
1408
1409         if (pi == job_list) {
1410                 job_list = pi->next;
1411         } else {
1412                 prev_pipe = job_list;
1413                 while (prev_pipe->next != pi)
1414                         prev_pipe = prev_pipe->next;
1415                 prev_pipe->next = pi->next;
1416         }
1417         if (job_list)
1418                 last_jobid = job_list->jobid;
1419         else
1420                 last_jobid = 0;
1421
1422         pi->stopped_progs = 0;
1423         free_pipe(pi, 0);
1424         free(pi);
1425 }
1426
1427 /* Checks to see if any processes have exited -- if they
1428    have, figure out why and see if a job has completed */
1429 static int checkjobs(struct pipe* fg_pipe)
1430 {
1431         int attributes;
1432         int status;
1433         int prognum = 0;
1434         struct pipe *pi;
1435         pid_t childpid;
1436
1437         attributes = WUNTRACED;
1438         if (fg_pipe==NULL) {
1439                 attributes |= WNOHANG;
1440         }
1441
1442         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1443                 if (fg_pipe) {
1444                         int i, rcode = 0;
1445                         for (i=0; i < fg_pipe->num_progs; i++) {
1446                                 if (fg_pipe->progs[i].pid == childpid) {
1447                                         if (i==fg_pipe->num_progs-1)
1448                                                 rcode=WEXITSTATUS(status);
1449                                         (fg_pipe->num_progs)--;
1450                                         return(rcode);
1451                                 }
1452                         }
1453                 }
1454
1455                 for (pi = job_list; pi; pi = pi->next) {
1456                         prognum = 0;
1457                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1458                                 prognum++;
1459                         }
1460                         if (prognum < pi->num_progs)
1461                                 break;
1462                 }
1463
1464                 if(pi==NULL) {
1465                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1466                         continue;
1467                 }
1468
1469                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1470                         /* child exited */
1471                         pi->running_progs--;
1472                         pi->progs[prognum].pid = 0;
1473
1474                         if (!pi->running_progs) {
1475                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1476                                 remove_bg_job(pi);
1477                         }
1478                 } else {
1479                         /* child stopped */
1480                         pi->stopped_progs++;
1481                         pi->progs[prognum].is_stopped = 1;
1482
1483 #if 0
1484                         /* Printing this stuff is a pain, since it tends to
1485                          * overwrite the prompt an inconveinient moments.  So
1486                          * don't do that.  */
1487                         if (pi->stopped_progs == pi->num_progs) {
1488                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1489                         }
1490 #endif
1491                 }
1492         }
1493
1494         if (childpid == -1 && errno != ECHILD)
1495                 perror_msg("waitpid");
1496
1497         /* move the shell to the foreground */
1498         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1499         /*      perror_msg("tcsetpgrp-2"); */
1500         return -1;
1501 }
1502
1503 /* Figure out our controlling tty, checking in order stderr,
1504  * stdin, and stdout.  If check_pgrp is set, also check that
1505  * we belong to the foreground process group associated with
1506  * that tty.  The value of shell_terminal is needed in order to call
1507  * tcsetpgrp(shell_terminal, ...); */
1508 void controlling_tty(int check_pgrp)
1509 {
1510         pid_t curpgrp;
1511
1512         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1513                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1514                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1515                 goto shell_terminal_error;
1516
1517         if (check_pgrp && curpgrp != getpgid(0))
1518                 goto shell_terminal_error;
1519
1520         return;
1521
1522 shell_terminal_error:
1523                 shell_terminal = -1;
1524                 return;
1525 }
1526 #endif
1527
1528 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1529  * to finish.  See checkjobs().
1530  *
1531  * return code is normally -1, when the caller has to wait for children
1532  * to finish to determine the exit status of the pipe.  If the pipe
1533  * is a simple builtin command, however, the action is done by the
1534  * time run_pipe_real returns, and the exit code is provided as the
1535  * return value.
1536  *
1537  * The input of the pipe is always stdin, the output is always
1538  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1539  * because it tries to avoid running the command substitution in
1540  * subshell, when that is in fact necessary.  The subshell process
1541  * now has its stdout directed to the input of the appropriate pipe,
1542  * so this routine is noticeably simpler.
1543  */
1544 static int run_pipe_real(struct pipe *pi)
1545 {
1546         int i;
1547 #ifndef __U_BOOT__
1548         int nextin, nextout;
1549         int pipefds[2];                         /* pipefds[0] is for reading */
1550         struct child_prog *child;
1551         struct built_in_command *x;
1552         char *p;
1553 # if __GNUC__
1554         /* Avoid longjmp clobbering */
1555         (void) &i;
1556         (void) &nextin;
1557         (void) &nextout;
1558         (void) &child;
1559 # endif
1560 #else
1561         int nextin;
1562         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1563         struct child_prog *child;
1564         cmd_tbl_t *cmdtp;
1565         char *p;
1566 # if __GNUC__
1567         /* Avoid longjmp clobbering */
1568         (void) &i;
1569         (void) &nextin;
1570         (void) &child;
1571 # endif
1572 #endif  /* __U_BOOT__ */
1573
1574         nextin = 0;
1575 #ifndef __U_BOOT__
1576         pi->pgrp = -1;
1577 #endif
1578
1579         /* Check if this is a simple builtin (not part of a pipe).
1580          * Builtins within pipes have to fork anyway, and are handled in
1581          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1582          */
1583         if (pi->num_progs == 1) child = & (pi->progs[0]);
1584 #ifndef __U_BOOT__
1585         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1586                 int squirrel[] = {-1, -1, -1};
1587                 int rcode;
1588                 debug_printf("non-subshell grouping\n");
1589                 setup_redirects(child, squirrel);
1590                 /* XXX could we merge code with following builtin case,
1591                  * by creating a pseudo builtin that calls run_list_real? */
1592                 rcode = run_list_real(child->group);
1593                 restore_redirects(squirrel);
1594 #else
1595                 if (pi->num_progs == 1 && child->group) {
1596                 int rcode;
1597                 debug_printf("non-subshell grouping\n");
1598                 rcode = run_list_real(child->group);
1599 #endif
1600                 return rcode;
1601         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1602                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1603                 if (i!=0 && child->argv[i]==NULL) {
1604                         /* assignments, but no command: set the local environment */
1605                         for (i=0; child->argv[i]!=NULL; i++) {
1606
1607                                 /* Ok, this case is tricky.  We have to decide if this is a
1608                                  * local variable, or an already exported variable.  If it is
1609                                  * already exported, we have to export the new value.  If it is
1610                                  * not exported, we need only set this as a local variable.
1611                                  * This junk is all to decide whether or not to export this
1612                                  * variable. */
1613                                 int export_me=0;
1614                                 char *name, *value;
1615                                 name = xstrdup(child->argv[i]);
1616                                 debug_printf("Local environment set: %s\n", name);
1617                                 value = strchr(name, '=');
1618                                 if (value)
1619                                         *value=0;
1620 #ifndef __U_BOOT__
1621                                 if ( get_local_var(name)) {
1622                                         export_me=1;
1623                                 }
1624 #endif
1625                                 free(name);
1626                                 p = insert_var_value(child->argv[i]);
1627                                 set_local_var(p, export_me);
1628                                 if (p != child->argv[i]) free(p);
1629                         }
1630                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1631                 }
1632                 for (i = 0; is_assignment(child->argv[i]); i++) {
1633                         p = insert_var_value(child->argv[i]);
1634 #ifndef __U_BOOT__
1635                         putenv(strdup(p));
1636 #else
1637                         set_local_var(p, 0);
1638 #endif
1639                         if (p != child->argv[i]) {
1640                                 child->sp--;
1641                                 free(p);
1642                         }
1643                 }
1644                 if (child->sp) {
1645                         char * str = NULL;
1646
1647                         str = make_string((child->argv + i));
1648                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1649                         free(str);
1650                         return last_return_code;
1651                 }
1652 #ifndef __U_BOOT__
1653                 for (x = bltins; x->cmd; x++) {
1654                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1655                                 int squirrel[] = {-1, -1, -1};
1656                                 int rcode;
1657                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1658                                         debug_printf("magic exec\n");
1659                                         setup_redirects(child,NULL);
1660                                         return EXIT_SUCCESS;
1661                                 }
1662                                 debug_printf("builtin inline %s\n", child->argv[0]);
1663                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1664                                  * This is perfect for work that comes after exec().
1665                                  * Is it really safe for inline use?  Experimentally,
1666                                  * things seem to work with glibc. */
1667                                 setup_redirects(child, squirrel);
1668 #else
1669                         /* check ";", because ,example , argv consist from
1670                          * "help;flinfo" must not execute
1671                          */
1672                         if (strchr(child->argv[i], ';')) {
1673                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1674                                         child->argv[i]);
1675                                 return -1;
1676                         }
1677                         /* Look up command in command table */
1678
1679
1680                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1681                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1682                                 return -1;      /* give up after bad command */
1683                         } else {
1684                                 int rcode;
1685 #if (CONFIG_COMMANDS & CFG_CMD_BOOTD)
1686             extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1687
1688                                 /* avoid "bootd" recursion */
1689                                 if (cmdtp->cmd == do_bootd) {
1690                                         if (flag & CMD_FLAG_BOOTD) {
1691                                                 printf ("'bootd' recursion detected\n");
1692                                                 return -1;
1693                                         }
1694                                 else
1695                                         flag |= CMD_FLAG_BOOTD;
1696                                 }
1697 #endif  /* CFG_CMD_BOOTD */
1698                                 /* found - check max args */
1699                                 if ((child->argc - i) > cmdtp->maxargs) {
1700                                         printf ("Usage:\n%s\n", cmdtp->usage);
1701                                         return -1;
1702                                 }
1703 #endif
1704                                 child->argv+=i;  /* XXX horrible hack */
1705 #ifndef __U_BOOT__
1706                                 rcode = x->function(child);
1707 #else
1708                                 /* OK - call function to do the command */
1709
1710                                 rcode = (cmdtp->cmd)
1711 (cmdtp, flag,child->argc-i,&child->argv[i]);
1712                                 if ( !cmdtp->repeatable )
1713                                         flag_repeat = 0;
1714
1715
1716 #endif
1717                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1718 #ifndef __U_BOOT__
1719
1720                                 restore_redirects(squirrel);
1721 #endif
1722
1723                                 return rcode;
1724                         }
1725                 }
1726 #ifndef __U_BOOT__
1727         }
1728
1729         for (i = 0; i < pi->num_progs; i++) {
1730                 child = & (pi->progs[i]);
1731
1732                 /* pipes are inserted between pairs of commands */
1733                 if ((i + 1) < pi->num_progs) {
1734                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1735                         nextout = pipefds[1];
1736                 } else {
1737                         nextout=1;
1738                         pipefds[0] = -1;
1739                 }
1740
1741                 /* XXX test for failed fork()? */
1742                 if (!(child->pid = fork())) {
1743                         /* Set the handling for job control signals back to the default.  */
1744                         signal(SIGINT, SIG_DFL);
1745                         signal(SIGQUIT, SIG_DFL);
1746                         signal(SIGTERM, SIG_DFL);
1747                         signal(SIGTSTP, SIG_DFL);
1748                         signal(SIGTTIN, SIG_DFL);
1749                         signal(SIGTTOU, SIG_DFL);
1750                         signal(SIGCHLD, SIG_DFL);
1751
1752                         close_all();
1753
1754                         if (nextin != 0) {
1755                                 dup2(nextin, 0);
1756                                 close(nextin);
1757                         }
1758                         if (nextout != 1) {
1759                                 dup2(nextout, 1);
1760                                 close(nextout);
1761                         }
1762                         if (pipefds[0]!=-1) {
1763                                 close(pipefds[0]);  /* opposite end of our output pipe */
1764                         }
1765
1766                         /* Like bash, explicit redirects override pipes,
1767                          * and the pipe fd is available for dup'ing. */
1768                         setup_redirects(child,NULL);
1769
1770                         if (interactive && pi->followup!=PIPE_BG) {
1771                                 /* If we (the child) win the race, put ourselves in the process
1772                                  * group whose leader is the first process in this pipe. */
1773                                 if (pi->pgrp < 0) {
1774                                         pi->pgrp = getpid();
1775                                 }
1776                                 if (setpgid(0, pi->pgrp) == 0) {
1777                                         tcsetpgrp(2, pi->pgrp);
1778                                 }
1779                         }
1780
1781                         pseudo_exec(child);
1782                 }
1783
1784
1785                 /* put our child in the process group whose leader is the
1786                    first process in this pipe */
1787                 if (pi->pgrp < 0) {
1788                         pi->pgrp = child->pid;
1789                 }
1790                 /* Don't check for errors.  The child may be dead already,
1791                  * in which case setpgid returns error code EACCES. */
1792                 setpgid(child->pid, pi->pgrp);
1793
1794                 if (nextin != 0)
1795                         close(nextin);
1796                 if (nextout != 1)
1797                         close(nextout);
1798
1799                 /* If there isn't another process, nextin is garbage
1800                    but it doesn't matter */
1801                 nextin = pipefds[0];
1802         }
1803 #endif
1804         return -1;
1805 }
1806
1807 static int run_list_real(struct pipe *pi)
1808 {
1809         char *save_name = NULL;
1810         char **list = NULL;
1811         char **save_list = NULL;
1812         struct pipe *rpipe;
1813         int flag_rep = 0;
1814 #ifndef __U_BOOT__
1815         int save_num_progs;
1816 #endif
1817         int rcode=0, flag_skip=1;
1818         int flag_restore = 0;
1819         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1820         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1821         /* check syntax for "for" */
1822         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1823                 if ((rpipe->r_mode == RES_IN ||
1824                     rpipe->r_mode == RES_FOR) &&
1825                     (rpipe->next == NULL)) {
1826                                 syntax();
1827 #ifdef __U_BOOT__
1828                                 flag_repeat = 0;
1829 #endif
1830                                 return 1;
1831                 }
1832                 if ((rpipe->r_mode == RES_IN &&
1833                         (rpipe->next->r_mode == RES_IN &&
1834                         rpipe->next->progs->argv != NULL))||
1835                         (rpipe->r_mode == RES_FOR &&
1836                         rpipe->next->r_mode != RES_IN)) {
1837                                 syntax();
1838 #ifdef __U_BOOT__
1839                                 flag_repeat = 0;
1840 #endif
1841                                 return 1;
1842                 }
1843         }
1844         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1845                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1846                         pi->r_mode == RES_FOR) {
1847 #ifdef __U_BOOT__
1848                                 /* check Ctrl-C */
1849                                 ctrlc();
1850                                 if ((had_ctrlc())) {
1851                                         return 1;
1852                                 }
1853 #endif
1854                                 flag_restore = 0;
1855                                 if (!rpipe) {
1856                                         flag_rep = 0;
1857                                         rpipe = pi;
1858                                 }
1859                 }
1860                 rmode = pi->r_mode;
1861                 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);
1862                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1863                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1864                         continue;
1865                 }
1866                 flag_skip = 1;
1867                 skip_more_in_this_rmode = RES_XXXX;
1868                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1869                 if (rmode == RES_THEN &&  if_code) continue;
1870                 if (rmode == RES_ELSE && !if_code) continue;
1871                 if (rmode == RES_ELIF && !if_code) break;
1872                 if (rmode == RES_FOR && pi->num_progs) {
1873                         if (!list) {
1874                                 /* if no variable values after "in" we skip "for" */
1875                                 if (!pi->next->progs->argv) continue;
1876                                 /* create list of variable values */
1877                                 list = make_list_in(pi->next->progs->argv,
1878                                         pi->progs->argv[0]);
1879                                 save_list = list;
1880                                 save_name = pi->progs->argv[0];
1881                                 pi->progs->argv[0] = NULL;
1882                                 flag_rep = 1;
1883                         }
1884                         if (!(*list)) {
1885                                 free(pi->progs->argv[0]);
1886                                 free(save_list);
1887                                 list = NULL;
1888                                 flag_rep = 0;
1889                                 pi->progs->argv[0] = save_name;
1890 #ifndef __U_BOOT__
1891                                 pi->progs->glob_result.gl_pathv[0] =
1892                                         pi->progs->argv[0];
1893 #endif
1894                                 continue;
1895                         } else {
1896                                 /* insert new value from list for variable */
1897                                 if (pi->progs->argv[0])
1898                                         free(pi->progs->argv[0]);
1899                                 pi->progs->argv[0] = *list++;
1900 #ifndef __U_BOOT__
1901                                 pi->progs->glob_result.gl_pathv[0] =
1902                                         pi->progs->argv[0];
1903 #endif
1904                         }
1905                 }
1906                 if (rmode == RES_IN) continue;
1907                 if (rmode == RES_DO) {
1908                         if (!flag_rep) continue;
1909                 }
1910                 if ((rmode == RES_DONE)) {
1911                         if (flag_rep) {
1912                                 flag_restore = 1;
1913                         } else {
1914                                 rpipe = NULL;
1915                         }
1916                 }
1917                 if (pi->num_progs == 0) continue;
1918 #ifndef __U_BOOT__
1919                 save_num_progs = pi->num_progs; /* save number of programs */
1920 #endif
1921                 rcode = run_pipe_real(pi);
1922                 debug_printf("run_pipe_real returned %d\n",rcode);
1923 #ifndef __U_BOOT__
1924                 if (rcode!=-1) {
1925                         /* We only ran a builtin: rcode was set by the return value
1926                          * of run_pipe_real(), and we don't need to wait for anything. */
1927                 } else if (pi->followup==PIPE_BG) {
1928                         /* XXX check bash's behavior with nontrivial pipes */
1929                         /* XXX compute jobid */
1930                         /* XXX what does bash do with attempts to background builtins? */
1931                         insert_bg_job(pi);
1932                         rcode = EXIT_SUCCESS;
1933                 } else {
1934                         if (interactive) {
1935                                 /* move the new process group into the foreground */
1936                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1937                                         perror_msg("tcsetpgrp-3");
1938                                 rcode = checkjobs(pi);
1939                                 /* move the shell to the foreground */
1940                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1941                                         perror_msg("tcsetpgrp-4");
1942                         } else {
1943                                 rcode = checkjobs(pi);
1944                         }
1945                         debug_printf("checkjobs returned %d\n",rcode);
1946                 }
1947                 last_return_code=rcode;
1948 #else
1949                 if (rcode < -1) {
1950                         last_return_code = -rcode - 2;
1951                         return -2;      /* exit */
1952                 }
1953                 last_return_code=(rcode == 0) ? 0 : 1;
1954 #endif
1955 #ifndef __U_BOOT__
1956                 pi->num_progs = save_num_progs; /* restore number of programs */
1957 #endif
1958                 if ( rmode == RES_IF || rmode == RES_ELIF )
1959                         next_if_code=rcode;  /* can be overwritten a number of times */
1960                 if (rmode == RES_WHILE)
1961                         flag_rep = !last_return_code;
1962                 if (rmode == RES_UNTIL)
1963                         flag_rep = last_return_code;
1964                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1965                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1966                         skip_more_in_this_rmode=rmode;
1967 #ifndef __U_BOOT__
1968                 checkjobs(NULL);
1969 #endif
1970         }
1971         return rcode;
1972 }
1973
1974 /* broken, of course, but OK for testing */
1975 static char *indenter(int i)
1976 {
1977         static char blanks[]="                                    ";
1978         return &blanks[sizeof(blanks)-i-1];
1979 }
1980
1981 /* return code is the exit status of the pipe */
1982 static int free_pipe(struct pipe *pi, int indent)
1983 {
1984         char **p;
1985         struct child_prog *child;
1986 #ifndef __U_BOOT__
1987         struct redir_struct *r, *rnext;
1988 #endif
1989         int a, i, ret_code=0;
1990         char *ind = indenter(indent);
1991
1992 #ifndef __U_BOOT__
1993         if (pi->stopped_progs > 0)
1994                 return ret_code;
1995         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1996 #endif
1997         for (i=0; i<pi->num_progs; i++) {
1998                 child = &pi->progs[i];
1999                 final_printf("%s  command %d:\n",ind,i);
2000                 if (child->argv) {
2001                         for (a=0,p=child->argv; *p; a++,p++) {
2002                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
2003                         }
2004 #ifndef __U_BOOT__
2005                         globfree(&child->glob_result);
2006 #else
2007                         for (a = child->argc;a >= 0;a--) {
2008                                 free(child->argv[a]);
2009                         }
2010                                         free(child->argv);
2011                         child->argc = 0;
2012 #endif
2013                         child->argv=NULL;
2014                 } else if (child->group) {
2015 #ifndef __U_BOOT__
2016                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
2017 #endif
2018                         ret_code = free_pipe_list(child->group,indent+3);
2019                         final_printf("%s   end group\n",ind);
2020                 } else {
2021                         final_printf("%s   (nil)\n",ind);
2022                 }
2023 #ifndef __U_BOOT__
2024                 for (r=child->redirects; r; r=rnext) {
2025                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2026                         if (r->dup == -1) {
2027                                 /* guard against the case >$FOO, where foo is unset or blank */
2028                                 if (r->word.gl_pathv) {
2029                                         final_printf(" %s\n", *r->word.gl_pathv);
2030                                         globfree(&r->word);
2031                                 }
2032                         } else {
2033                                 final_printf("&%d\n", r->dup);
2034                         }
2035                         rnext=r->next;
2036                         free(r);
2037                 }
2038                 child->redirects=NULL;
2039 #endif
2040         }
2041         free(pi->progs);   /* children are an array, they get freed all at once */
2042         pi->progs=NULL;
2043         return ret_code;
2044 }
2045
2046 static int free_pipe_list(struct pipe *head, int indent)
2047 {
2048         int rcode=0;   /* if list has no members */
2049         struct pipe *pi, *next;
2050         char *ind = indenter(indent);
2051         for (pi=head; pi; pi=next) {
2052                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2053                 rcode = free_pipe(pi, indent);
2054                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2055                 next=pi->next;
2056                 pi->next=NULL;
2057                 free(pi);
2058         }
2059         return rcode;
2060 }
2061
2062 /* Select which version we will use */
2063 static int run_list(struct pipe *pi)
2064 {
2065         int rcode=0;
2066 #ifndef __U_BOOT__
2067         if (fake_mode==0) {
2068 #endif
2069                 rcode = run_list_real(pi);
2070 #ifndef __U_BOOT__
2071         }
2072 #endif
2073         /* free_pipe_list has the side effect of clearing memory
2074          * In the long run that function can be merged with run_list_real,
2075          * but doing that now would hobble the debugging effort. */
2076         free_pipe_list(pi,0);
2077         return rcode;
2078 }
2079
2080 /* The API for glob is arguably broken.  This routine pushes a non-matching
2081  * string into the output structure, removing non-backslashed backslashes.
2082  * If someone can prove me wrong, by performing this function within the
2083  * original glob(3) api, feel free to rewrite this routine into oblivion.
2084  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2085  * XXX broken if the last character is '\\', check that before calling.
2086  */
2087 #ifndef __U_BOOT__
2088 static int globhack(const char *src, int flags, glob_t *pglob)
2089 {
2090         int cnt=0, pathc;
2091         const char *s;
2092         char *dest;
2093         for (cnt=1, s=src; s && *s; s++) {
2094                 if (*s == '\\') s++;
2095                 cnt++;
2096         }
2097         dest = malloc(cnt);
2098         if (!dest) return GLOB_NOSPACE;
2099         if (!(flags & GLOB_APPEND)) {
2100                 pglob->gl_pathv=NULL;
2101                 pglob->gl_pathc=0;
2102                 pglob->gl_offs=0;
2103                 pglob->gl_offs=0;
2104         }
2105         pathc = ++pglob->gl_pathc;
2106         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2107         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2108         pglob->gl_pathv[pathc-1]=dest;
2109         pglob->gl_pathv[pathc]=NULL;
2110         for (s=src; s && *s; s++, dest++) {
2111                 if (*s == '\\') s++;
2112                 *dest = *s;
2113         }
2114         *dest='\0';
2115         return 0;
2116 }
2117
2118 /* XXX broken if the last character is '\\', check that before calling */
2119 static int glob_needed(const char *s)
2120 {
2121         for (; *s; s++) {
2122                 if (*s == '\\') s++;
2123                 if (strchr("*[?",*s)) return 1;
2124         }
2125         return 0;
2126 }
2127
2128 #if 0
2129 static void globprint(glob_t *pglob)
2130 {
2131         int i;
2132         debug_printf("glob_t at %p:\n", pglob);
2133         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2134                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2135         for (i=0; i<pglob->gl_pathc; i++)
2136                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2137                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2138 }
2139 #endif
2140
2141 static int xglob(o_string *dest, int flags, glob_t *pglob)
2142 {
2143         int gr;
2144
2145         /* short-circuit for null word */
2146         /* we can code this better when the debug_printf's are gone */
2147         if (dest->length == 0) {
2148                 if (dest->nonnull) {
2149                         /* bash man page calls this an "explicit" null */
2150                         gr = globhack(dest->data, flags, pglob);
2151                         debug_printf("globhack returned %d\n",gr);
2152                 } else {
2153                         return 0;
2154                 }
2155         } else if (glob_needed(dest->data)) {
2156                 gr = glob(dest->data, flags, NULL, pglob);
2157                 debug_printf("glob returned %d\n",gr);
2158                 if (gr == GLOB_NOMATCH) {
2159                         /* quote removal, or more accurately, backslash removal */
2160                         gr = globhack(dest->data, flags, pglob);
2161                         debug_printf("globhack returned %d\n",gr);
2162                 }
2163         } else {
2164                 gr = globhack(dest->data, flags, pglob);
2165                 debug_printf("globhack returned %d\n",gr);
2166         }
2167         if (gr == GLOB_NOSPACE)
2168                 error_msg_and_die("out of memory during glob");
2169         if (gr != 0) { /* GLOB_ABORTED ? */
2170                 error_msg("glob(3) error %d",gr);
2171         }
2172         /* globprint(glob_target); */
2173         return gr;
2174 }
2175 #endif
2176
2177 #ifdef __U_BOOT__
2178 static char *get_dollar_var(char ch);
2179 #endif
2180
2181 /* This is used to get/check local shell variables */
2182 static char *get_local_var(const char *s)
2183 {
2184         struct variables *cur;
2185
2186         if (!s)
2187                 return NULL;
2188
2189 #ifdef __U_BOOT__
2190         if (*s == '$')
2191                 return get_dollar_var(s[1]);
2192 #endif
2193
2194         for (cur = top_vars; cur; cur=cur->next)
2195                 if(strcmp(cur->name, s)==0)
2196                         return cur->value;
2197         return NULL;
2198 }
2199
2200 /* This is used to set local shell variables
2201    flg_export==0 if only local (not exporting) variable
2202    flg_export==1 if "new" exporting environ
2203    flg_export>1  if current startup environ (not call putenv()) */
2204 static int set_local_var(const char *s, int flg_export)
2205 {
2206         char *name, *value;
2207         int result=0;
2208         struct variables *cur;
2209
2210 #ifdef __U_BOOT__
2211         /* might be possible! */
2212         if (!isalpha(*s))
2213                 return -1;
2214 #endif
2215
2216         name=strdup(s);
2217
2218 #ifdef __U_BOOT__
2219         if (getenv(name) != NULL) {
2220                 printf ("ERROR: "
2221                                 "There is a global environment variable with the same name.\n");
2222                 free(name);
2223                 return -1;
2224         }
2225 #endif
2226         /* Assume when we enter this function that we are already in
2227          * NAME=VALUE format.  So the first order of business is to
2228          * split 's' on the '=' into 'name' and 'value' */
2229         value = strchr(name, '=');
2230         if (value==0 && ++value==0) {
2231                 free(name);
2232                 return -1;
2233         }
2234         *value++ = 0;
2235
2236         for(cur = top_vars; cur; cur = cur->next) {
2237                 if(strcmp(cur->name, name)==0)
2238                         break;
2239         }
2240
2241         if(cur) {
2242                 if(strcmp(cur->value, value)==0) {
2243                         if(flg_export>0 && cur->flg_export==0)
2244                                 cur->flg_export=flg_export;
2245                         else
2246                                 result++;
2247                 } else {
2248                         if(cur->flg_read_only) {
2249                                 error_msg("%s: readonly variable", name);
2250                                 result = -1;
2251                         } else {
2252                                 if(flg_export>0 || cur->flg_export>1)
2253                                         cur->flg_export=1;
2254                                 free(cur->value);
2255
2256                                 cur->value = strdup(value);
2257                         }
2258                 }
2259         } else {
2260                 cur = malloc(sizeof(struct variables));
2261                 if(!cur) {
2262                         result = -1;
2263                 } else {
2264                         cur->name = strdup(name);
2265                         if(cur->name == 0) {
2266                                 free(cur);
2267                                 result = -1;
2268                         } else {
2269                                 struct variables *bottom = top_vars;
2270                                 cur->value = strdup(value);
2271                                 cur->next = 0;
2272                                 cur->flg_export = flg_export;
2273                                 cur->flg_read_only = 0;
2274                                 while(bottom->next) bottom=bottom->next;
2275                                 bottom->next = cur;
2276                         }
2277                 }
2278         }
2279
2280 #ifndef __U_BOOT__
2281         if(result==0 && cur->flg_export==1) {
2282                 *(value-1) = '=';
2283                 result = putenv(name);
2284         } else {
2285 #endif
2286                 free(name);
2287 #ifndef __U_BOOT__
2288                 if(result>0)            /* equivalent to previous set */
2289                         result = 0;
2290         }
2291 #endif
2292         return result;
2293 }
2294
2295 #ifndef __U_BOOT__
2296 static void unset_local_var(const char *name)
2297 {
2298         struct variables *cur;
2299
2300         if (name) {
2301                 for (cur = top_vars; cur; cur=cur->next) {
2302                         if(strcmp(cur->name, name)==0)
2303                                 break;
2304                 }
2305                 if(cur!=0) {
2306                         struct variables *next = top_vars;
2307                         if(cur->flg_read_only) {
2308                                 error_msg("%s: readonly variable", name);
2309                                 return;
2310                         } else {
2311                                 if(cur->flg_export)
2312                                         unsetenv(cur->name);
2313                                 free(cur->name);
2314                                 free(cur->value);
2315                                 while (next->next != cur)
2316                                         next = next->next;
2317                                 next->next = cur->next;
2318                         }
2319                         free(cur);
2320                 }
2321         }
2322 }
2323 #endif
2324
2325 static int is_assignment(const char *s)
2326 {
2327         if (s == NULL)
2328                 return 0;
2329
2330         if (!isalpha(*s)) return 0;
2331         ++s;
2332         while(isalnum(*s) || *s=='_') ++s;
2333         return *s=='=';
2334 }
2335
2336 #ifndef __U_BOOT__
2337 /* the src parameter allows us to peek forward to a possible &n syntax
2338  * for file descriptor duplication, e.g., "2>&1".
2339  * Return code is 0 normally, 1 if a syntax error is detected in src.
2340  * Resource errors (in xmalloc) cause the process to exit */
2341 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2342         struct in_str *input)
2343 {
2344         struct child_prog *child=ctx->child;
2345         struct redir_struct *redir = child->redirects;
2346         struct redir_struct *last_redir=NULL;
2347
2348         /* Create a new redir_struct and drop it onto the end of the linked list */
2349         while(redir) {
2350                 last_redir=redir;
2351                 redir=redir->next;
2352         }
2353         redir = xmalloc(sizeof(struct redir_struct));
2354         redir->next=NULL;
2355         redir->word.gl_pathv=NULL;
2356         if (last_redir) {
2357                 last_redir->next=redir;
2358         } else {
2359                 child->redirects=redir;
2360         }
2361
2362         redir->type=style;
2363         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2364
2365         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2366
2367         /* Check for a '2>&1' type redirect */
2368         redir->dup = redirect_dup_num(input);
2369         if (redir->dup == -2) return 1;  /* syntax error */
2370         if (redir->dup != -1) {
2371                 /* Erik had a check here that the file descriptor in question
2372                  * is legit; I postpone that to "run time"
2373                  * A "-" representation of "close me" shows up as a -3 here */
2374                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2375         } else {
2376                 /* We do _not_ try to open the file that src points to,
2377                  * since we need to return and let src be expanded first.
2378                  * Set ctx->pending_redirect, so we know what to do at the
2379                  * end of the next parsed word.
2380                  */
2381                 ctx->pending_redirect = redir;
2382         }
2383         return 0;
2384 }
2385 #endif
2386
2387 struct pipe *new_pipe(void) {
2388         struct pipe *pi;
2389         pi = xmalloc(sizeof(struct pipe));
2390         pi->num_progs = 0;
2391         pi->progs = NULL;
2392         pi->next = NULL;
2393         pi->followup = 0;  /* invalid */
2394         pi->r_mode = RES_NONE;
2395         return pi;
2396 }
2397
2398 static void initialize_context(struct p_context *ctx)
2399 {
2400         ctx->pipe=NULL;
2401 #ifndef __U_BOOT__
2402         ctx->pending_redirect=NULL;
2403 #endif
2404         ctx->child=NULL;
2405         ctx->list_head=new_pipe();
2406         ctx->pipe=ctx->list_head;
2407         ctx->w=RES_NONE;
2408         ctx->stack=NULL;
2409 #ifdef __U_BOOT__
2410         ctx->old_flag=0;
2411 #endif
2412         done_command(ctx);   /* creates the memory for working child */
2413 }
2414
2415 /* normal return is 0
2416  * if a reserved word is found, and processed, return 1
2417  * should handle if, then, elif, else, fi, for, while, until, do, done.
2418  * case, function, and select are obnoxious, save those for later.
2419  */
2420 struct reserved_combo {
2421         char *literal;
2422         int code;
2423         long flag;
2424 };
2425 /* Mostly a list of accepted follow-up reserved words.
2426  * FLAG_END means we are done with the sequence, and are ready
2427  * to turn the compound list into a command.
2428  * FLAG_START means the word must start a new compound list.
2429  */
2430 static struct reserved_combo reserved_list[] = {
2431         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2432         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2433         { "elif",  RES_ELIF,  FLAG_THEN },
2434         { "else",  RES_ELSE,  FLAG_FI   },
2435         { "fi",    RES_FI,    FLAG_END  },
2436         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2437         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2438         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2439         { "in",    RES_IN,    FLAG_DO   },
2440         { "do",    RES_DO,    FLAG_DONE },
2441         { "done",  RES_DONE,  FLAG_END  }
2442 };
2443 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2444
2445 int reserved_word(o_string *dest, struct p_context *ctx)
2446 {
2447         struct reserved_combo *r;
2448         for (r=reserved_list;
2449                 r<reserved_list+NRES; r++) {
2450                 if (strcmp(dest->data, r->literal) == 0) {
2451                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2452                         if (r->flag & FLAG_START) {
2453                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2454                                 debug_printf("push stack\n");
2455                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2456                                         syntax();
2457                                         free(new);
2458                                         ctx->w = RES_SNTX;
2459                                         b_reset(dest);
2460                                         return 1;
2461                                 }
2462                                 *new = *ctx;   /* physical copy */
2463                                 initialize_context(ctx);
2464                                 ctx->stack=new;
2465                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2466                                 syntax();
2467                                 ctx->w = RES_SNTX;
2468                                 b_reset(dest);
2469                                 return 1;
2470                         }
2471                         ctx->w=r->code;
2472                         ctx->old_flag = r->flag;
2473                         if (ctx->old_flag & FLAG_END) {
2474                                 struct p_context *old;
2475                                 debug_printf("pop stack\n");
2476                                 done_pipe(ctx,PIPE_SEQ);
2477                                 old = ctx->stack;
2478                                 old->child->group = ctx->list_head;
2479 #ifndef __U_BOOT__
2480                                 old->child->subshell = 0;
2481 #endif
2482                                 *ctx = *old;   /* physical copy */
2483                                 free(old);
2484                         }
2485                         b_reset (dest);
2486                         return 1;
2487                 }
2488         }
2489         return 0;
2490 }
2491
2492 /* normal return is 0.
2493  * Syntax or xglob errors return 1. */
2494 static int done_word(o_string *dest, struct p_context *ctx)
2495 {
2496         struct child_prog *child=ctx->child;
2497 #ifndef __U_BOOT__
2498         glob_t *glob_target;
2499         int gr, flags = 0;
2500 #else
2501         char *str, *s;
2502         int argc, cnt;
2503 #endif
2504
2505         debug_printf("done_word: %s %p\n", dest->data, child);
2506         if (dest->length == 0 && !dest->nonnull) {
2507                 debug_printf("  true null, ignored\n");
2508                 return 0;
2509         }
2510 #ifndef __U_BOOT__
2511         if (ctx->pending_redirect) {
2512                 glob_target = &ctx->pending_redirect->word;
2513         } else {
2514 #endif
2515                 if (child->group) {
2516                         syntax();
2517                         return 1;  /* syntax error, groups and arglists don't mix */
2518                 }
2519                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2520                         debug_printf("checking %s for reserved-ness\n",dest->data);
2521                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2522                 }
2523 #ifndef __U_BOOT__
2524                 glob_target = &child->glob_result;
2525                 if (child->argv) flags |= GLOB_APPEND;
2526 #else
2527                 for (cnt = 1, s = dest->data; s && *s; s++) {
2528                         if (*s == '\\') s++;
2529                         cnt++;
2530                 }
2531                 str = malloc(cnt);
2532                 if (!str) return 1;
2533                 if ( child->argv == NULL) {
2534                         child->argc=0;
2535                 }
2536                 argc = ++child->argc;
2537                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2538                 if (child->argv == NULL) return 1;
2539                 child->argv[argc-1]=str;
2540                 child->argv[argc]=NULL;
2541                 for (s = dest->data; s && *s; s++,str++) {
2542                         if (*s == '\\') s++;
2543                         *str = *s;
2544                 }
2545                 *str = '\0';
2546 #endif
2547 #ifndef __U_BOOT__
2548         }
2549         gr = xglob(dest, flags, glob_target);
2550         if (gr != 0) return 1;
2551 #endif
2552
2553         b_reset(dest);
2554 #ifndef __U_BOOT__
2555         if (ctx->pending_redirect) {
2556                 ctx->pending_redirect=NULL;
2557                 if (glob_target->gl_pathc != 1) {
2558                         error_msg("ambiguous redirect");
2559                         return 1;
2560                 }
2561         } else {
2562                 child->argv = glob_target->gl_pathv;
2563         }
2564 #endif
2565         if (ctx->w == RES_FOR) {
2566                 done_word(dest,ctx);
2567                 done_pipe(ctx,PIPE_SEQ);
2568         }
2569         return 0;
2570 }
2571
2572 /* The only possible error here is out of memory, in which case
2573  * xmalloc exits. */
2574 static int done_command(struct p_context *ctx)
2575 {
2576         /* The child is really already in the pipe structure, so
2577          * advance the pipe counter and make a new, null child.
2578          * Only real trickiness here is that the uncommitted
2579          * child structure, to which ctx->child points, is not
2580          * counted in pi->num_progs. */
2581         struct pipe *pi=ctx->pipe;
2582         struct child_prog *prog=ctx->child;
2583
2584         if (prog && prog->group == NULL
2585                  && prog->argv == NULL
2586 #ifndef __U_BOOT__
2587                  && prog->redirects == NULL) {
2588 #else
2589                                                                                 ) {
2590 #endif
2591                 debug_printf("done_command: skipping null command\n");
2592                 return 0;
2593         } else if (prog) {
2594                 pi->num_progs++;
2595                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2596         } else {
2597                 debug_printf("done_command: initializing\n");
2598         }
2599         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2600
2601         prog = pi->progs + pi->num_progs;
2602 #ifndef __U_BOOT__
2603         prog->redirects = NULL;
2604 #endif
2605         prog->argv = NULL;
2606 #ifndef __U_BOOT__
2607         prog->is_stopped = 0;
2608 #endif
2609         prog->group = NULL;
2610 #ifndef __U_BOOT__
2611         prog->glob_result.gl_pathv = NULL;
2612         prog->family = pi;
2613 #endif
2614         prog->sp = 0;
2615         ctx->child = prog;
2616         prog->type = ctx->type;
2617
2618         /* but ctx->pipe and ctx->list_head remain unchanged */
2619         return 0;
2620 }
2621
2622 static int done_pipe(struct p_context *ctx, pipe_style type)
2623 {
2624         struct pipe *new_p;
2625         done_command(ctx);  /* implicit closure of previous command */
2626         debug_printf("done_pipe, type %d\n", type);
2627         ctx->pipe->followup = type;
2628         ctx->pipe->r_mode = ctx->w;
2629         new_p=new_pipe();
2630         ctx->pipe->next = new_p;
2631         ctx->pipe = new_p;
2632         ctx->child = NULL;
2633         done_command(ctx);  /* set up new pipe to accept commands */
2634         return 0;
2635 }
2636
2637 #ifndef __U_BOOT__
2638 /* peek ahead in the in_str to find out if we have a "&n" construct,
2639  * as in "2>&1", that represents duplicating a file descriptor.
2640  * returns either -2 (syntax error), -1 (no &), or the number found.
2641  */
2642 static int redirect_dup_num(struct in_str *input)
2643 {
2644         int ch, d=0, ok=0;
2645         ch = b_peek(input);
2646         if (ch != '&') return -1;
2647
2648         b_getch(input);  /* get the & */
2649         ch=b_peek(input);
2650         if (ch == '-') {
2651                 b_getch(input);
2652                 return -3;  /* "-" represents "close me" */
2653         }
2654         while (isdigit(ch)) {
2655                 d = d*10+(ch-'0');
2656                 ok=1;
2657                 b_getch(input);
2658                 ch = b_peek(input);
2659         }
2660         if (ok) return d;
2661
2662         error_msg("ambiguous redirect");
2663         return -2;
2664 }
2665
2666 /* If a redirect is immediately preceded by a number, that number is
2667  * supposed to tell which file descriptor to redirect.  This routine
2668  * looks for such preceding numbers.  In an ideal world this routine
2669  * needs to handle all the following classes of redirects...
2670  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2671  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2672  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2673  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2674  * A -1 output from this program means no valid number was found, so the
2675  * caller should use the appropriate default for this redirection.
2676  */
2677 static int redirect_opt_num(o_string *o)
2678 {
2679         int num;
2680
2681         if (o->length==0) return -1;
2682         for(num=0; num<o->length; num++) {
2683                 if (!isdigit(*(o->data+num))) {
2684                         return -1;
2685                 }
2686         }
2687         /* reuse num (and save an int) */
2688         num=atoi(o->data);
2689         b_reset(o);
2690         return num;
2691 }
2692
2693 FILE *generate_stream_from_list(struct pipe *head)
2694 {
2695         FILE *pf;
2696 #if 1
2697         int pid, channel[2];
2698         if (pipe(channel)<0) perror_msg_and_die("pipe");
2699         pid=fork();
2700         if (pid<0) {
2701                 perror_msg_and_die("fork");
2702         } else if (pid==0) {
2703                 close(channel[0]);
2704                 if (channel[1] != 1) {
2705                         dup2(channel[1],1);
2706                         close(channel[1]);
2707                 }
2708 #if 0
2709 #define SURROGATE "surrogate response"
2710                 write(1,SURROGATE,sizeof(SURROGATE));
2711                 _exit(run_list(head));
2712 #else
2713                 _exit(run_list_real(head));   /* leaks memory */
2714 #endif
2715         }
2716         debug_printf("forked child %d\n",pid);
2717         close(channel[1]);
2718         pf = fdopen(channel[0],"r");
2719         debug_printf("pipe on FILE *%p\n",pf);
2720 #else
2721         free_pipe_list(head,0);
2722         pf=popen("echo surrogate response","r");
2723         debug_printf("started fake pipe on FILE *%p\n",pf);
2724 #endif
2725         return pf;
2726 }
2727
2728 /* this version hacked for testing purposes */
2729 /* return code is exit status of the process that is run. */
2730 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2731 {
2732         int retcode;
2733         o_string result=NULL_O_STRING;
2734         struct p_context inner;
2735         FILE *p;
2736         struct in_str pipe_str;
2737         initialize_context(&inner);
2738
2739         /* recursion to generate command */
2740         retcode = parse_stream(&result, &inner, input, subst_end);
2741         if (retcode != 0) return retcode;  /* syntax error or EOF */
2742         done_word(&result, &inner);
2743         done_pipe(&inner, PIPE_SEQ);
2744         b_free(&result);
2745
2746         p=generate_stream_from_list(inner.list_head);
2747         if (p==NULL) return 1;
2748         mark_open(fileno(p));
2749         setup_file_in_str(&pipe_str, p);
2750
2751         /* now send results of command back into original context */
2752         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2753         /* XXX In case of a syntax error, should we try to kill the child?
2754          * That would be tough to do right, so just read until EOF. */
2755         if (retcode == 1) {
2756                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2757         }
2758
2759         debug_printf("done reading from pipe, pclose()ing\n");
2760         /* This is the step that wait()s for the child.  Should be pretty
2761          * safe, since we just read an EOF from its stdout.  We could try
2762          * to better, by using wait(), and keeping track of background jobs
2763          * at the same time.  That would be a lot of work, and contrary
2764          * to the KISS philosophy of this program. */
2765         mark_closed(fileno(p));
2766         retcode=pclose(p);
2767         free_pipe_list(inner.list_head,0);
2768         debug_printf("pclosed, retcode=%d\n",retcode);
2769         /* XXX this process fails to trim a single trailing newline */
2770         return retcode;
2771 }
2772
2773 static int parse_group(o_string *dest, struct p_context *ctx,
2774         struct in_str *input, int ch)
2775 {
2776         int rcode, endch=0;
2777         struct p_context sub;
2778         struct child_prog *child = ctx->child;
2779         if (child->argv) {
2780                 syntax();
2781                 return 1;  /* syntax error, groups and arglists don't mix */
2782         }
2783         initialize_context(&sub);
2784         switch(ch) {
2785                 case '(': endch=')'; child->subshell=1; break;
2786                 case '{': endch='}'; break;
2787                 default: syntax();   /* really logic error */
2788         }
2789         rcode=parse_stream(dest,&sub,input,endch);
2790         done_word(dest,&sub); /* finish off the final word in the subcontext */
2791         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2792         child->group = sub.list_head;
2793         return rcode;
2794         /* child remains "open", available for possible redirects */
2795 }
2796 #endif
2797
2798 /* basically useful version until someone wants to get fancier,
2799  * see the bash man page under "Parameter Expansion" */
2800 static char *lookup_param(char *src)
2801 {
2802         char *p;
2803
2804         if (!src)
2805                 return NULL;
2806
2807                 p = getenv(src);
2808                 if (!p)
2809                         p = get_local_var(src);
2810
2811         return p;
2812 }
2813
2814 #ifdef __U_BOOT__
2815 static char *get_dollar_var(char ch)
2816 {
2817         static char buf[40];
2818
2819         buf[0] = '\0';
2820         switch (ch) {
2821                 case '?':
2822                         sprintf(buf, "%u", (unsigned int)last_return_code);
2823                         break;
2824                 default:
2825                         return NULL;
2826         }
2827         return buf;
2828 }
2829 #endif
2830
2831 /* return code: 0 for OK, 1 for syntax error */
2832 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2833 {
2834 #ifndef __U_BOOT__
2835         int i, advance=0;
2836 #else
2837         int advance=0;
2838 #endif
2839 #ifndef __U_BOOT__
2840         char sep[]=" ";
2841 #endif
2842         int ch = input->peek(input);  /* first character after the $ */
2843         debug_printf("handle_dollar: ch=%c\n",ch);
2844         if (isalpha(ch)) {
2845                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2846                 ctx->child->sp++;
2847                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2848                         b_getch(input);
2849                         b_addchr(dest,ch);
2850                 }
2851                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2852 #ifndef __U_BOOT__
2853         } else if (isdigit(ch)) {
2854                 i = ch-'0';  /* XXX is $0 special? */
2855                 if (i<global_argc) {
2856                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2857                 }
2858                 advance = 1;
2859 #endif
2860         } else switch (ch) {
2861 #ifndef __U_BOOT__
2862                 case '$':
2863                         b_adduint(dest,getpid());
2864                         advance = 1;
2865                         break;
2866                 case '!':
2867                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2868                         advance = 1;
2869                         break;
2870 #endif
2871                 case '?':
2872 #ifndef __U_BOOT__
2873                         b_adduint(dest,last_return_code);
2874 #else
2875                         ctx->child->sp++;
2876                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2877                         b_addchr(dest, '$');
2878                         b_addchr(dest, '?');
2879                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2880 #endif
2881                         advance = 1;
2882                         break;
2883 #ifndef __U_BOOT__
2884                 case '#':
2885                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2886                         advance = 1;
2887                         break;
2888 #endif
2889                 case '{':
2890                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2891                         ctx->child->sp++;
2892                         b_getch(input);
2893                         /* XXX maybe someone will try to escape the '}' */
2894                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2895                                 b_addchr(dest,ch);
2896                         }
2897                         if (ch != '}') {
2898                                 syntax();
2899                                 return 1;
2900                         }
2901                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2902                         break;
2903 #ifndef __U_BOOT__
2904                 case '(':
2905                         b_getch(input);
2906                         process_command_subs(dest, ctx, input, ')');
2907                         break;
2908                 case '*':
2909                         sep[0]=ifs[0];
2910                         for (i=1; i<global_argc; i++) {
2911                                 parse_string(dest, ctx, global_argv[i]);
2912                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2913                         }
2914                         break;
2915                 case '@':
2916                 case '-':
2917                 case '_':
2918                         /* still unhandled, but should be eventually */
2919                         error_msg("unhandled syntax: $%c",ch);
2920                         return 1;
2921                         break;
2922 #endif
2923                 default:
2924                         b_addqchr(dest,'$',dest->quote);
2925         }
2926         /* Eat the character if the flag was set.  If the compiler
2927          * is smart enough, we could substitute "b_getch(input);"
2928          * for all the "advance = 1;" above, and also end up with
2929          * a nice size-optimized program.  Hah!  That'll be the day.
2930          */
2931         if (advance) b_getch(input);
2932         return 0;
2933 }
2934
2935 #ifndef __U_BOOT__
2936 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2937 {
2938         struct in_str foo;
2939         setup_string_in_str(&foo, src);
2940         return parse_stream(dest, ctx, &foo, '\0');
2941 }
2942 #endif
2943
2944 /* return code is 0 for normal exit, 1 for syntax error */
2945 int parse_stream(o_string *dest, struct p_context *ctx,
2946         struct in_str *input, int end_trigger)
2947 {
2948         unsigned int ch, m;
2949 #ifndef __U_BOOT__
2950         int redir_fd;
2951         redir_type redir_style;
2952 #endif
2953         int next;
2954
2955         /* Only double-quote state is handled in the state variable dest->quote.
2956          * A single-quote triggers a bypass of the main loop until its mate is
2957          * found.  When recursing, quote state is passed in via dest->quote. */
2958
2959         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2960         while ((ch=b_getch(input))!=EOF) {
2961                 m = map[ch];
2962 #ifdef __U_BOOT__
2963                 if (input->__promptme == 0) return 1;
2964 #endif
2965                 next = (ch == '\n') ? 0 : b_peek(input);
2966
2967                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2968                         ch >= ' ' ? ch : '.', ch, m,
2969                         dest->quote, ctx->stack == NULL ? '*' : '.');
2970
2971                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2972                         b_addqchr(dest, ch, dest->quote);
2973                 } else {
2974                         if (m==2) {  /* unquoted IFS */
2975                                 if (done_word(dest, ctx)) {
2976                                         return 1;
2977                                 }
2978                                 /* If we aren't performing a substitution, treat a newline as a
2979                                  * command separator.  */
2980                                 if (end_trigger != '\0' && ch=='\n')
2981                                         done_pipe(ctx,PIPE_SEQ);
2982                         }
2983                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2984                                 debug_printf("leaving parse_stream (triggered)\n");
2985                                 return 0;
2986                         }
2987 #if 0
2988                         if (ch=='\n') {
2989                                 /* Yahoo!  Time to run with it! */
2990                                 done_pipe(ctx,PIPE_SEQ);
2991                                 run_list(ctx->list_head);
2992                                 initialize_context(ctx);
2993                         }
2994 #endif
2995                         if (m!=2) switch (ch) {
2996                 case '#':
2997                         if (dest->length == 0 && !dest->quote) {
2998                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2999                         } else {
3000                                 b_addqchr(dest, ch, dest->quote);
3001                         }
3002                         break;
3003                 case '\\':
3004                         if (next == EOF) {
3005                                 syntax();
3006                                 return 1;
3007                         }
3008                         b_addqchr(dest, '\\', dest->quote);
3009                         b_addqchr(dest, b_getch(input), dest->quote);
3010                         break;
3011                 case '$':
3012                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3013                         break;
3014                 case '\'':
3015                         dest->nonnull = 1;
3016                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3017 #ifdef __U_BOOT__
3018                                 if(input->__promptme == 0) return 1;
3019 #endif
3020                                 b_addchr(dest,ch);
3021                         }
3022                         if (ch==EOF) {
3023                                 syntax();
3024                                 return 1;
3025                         }
3026                         break;
3027                 case '"':
3028                         dest->nonnull = 1;
3029                         dest->quote = !dest->quote;
3030                         break;
3031 #ifndef __U_BOOT__
3032                 case '`':
3033                         process_command_subs(dest, ctx, input, '`');
3034                         break;
3035                 case '>':
3036                         redir_fd = redirect_opt_num(dest);
3037                         done_word(dest, ctx);
3038                         redir_style=REDIRECT_OVERWRITE;
3039                         if (next == '>') {
3040                                 redir_style=REDIRECT_APPEND;
3041                                 b_getch(input);
3042                         } else if (next == '(') {
3043                                 syntax();   /* until we support >(list) Process Substitution */
3044                                 return 1;
3045                         }
3046                         setup_redirect(ctx, redir_fd, redir_style, input);
3047                         break;
3048                 case '<':
3049                         redir_fd = redirect_opt_num(dest);
3050                         done_word(dest, ctx);
3051                         redir_style=REDIRECT_INPUT;
3052                         if (next == '<') {
3053                                 redir_style=REDIRECT_HEREIS;
3054                                 b_getch(input);
3055                         } else if (next == '>') {
3056                                 redir_style=REDIRECT_IO;
3057                                 b_getch(input);
3058                         } else if (next == '(') {
3059                                 syntax();   /* until we support <(list) Process Substitution */
3060                                 return 1;
3061                         }
3062                         setup_redirect(ctx, redir_fd, redir_style, input);
3063                         break;
3064 #endif
3065                 case ';':
3066                         done_word(dest, ctx);
3067                         done_pipe(ctx,PIPE_SEQ);
3068                         break;
3069                 case '&':
3070                         done_word(dest, ctx);
3071                         if (next=='&') {
3072                                 b_getch(input);
3073                                 done_pipe(ctx,PIPE_AND);
3074                         } else {
3075 #ifndef __U_BOOT__
3076                                 done_pipe(ctx,PIPE_BG);
3077 #else
3078                                 syntax_err();
3079                                 return 1;
3080 #endif
3081                         }
3082                         break;
3083                 case '|':
3084                         done_word(dest, ctx);
3085                         if (next=='|') {
3086                                 b_getch(input);
3087                                 done_pipe(ctx,PIPE_OR);
3088                         } else {
3089                                 /* we could pick up a file descriptor choice here
3090                                  * with redirect_opt_num(), but bash doesn't do it.
3091                                  * "echo foo 2| cat" yields "foo 2". */
3092 #ifndef __U_BOOT__
3093                                 done_command(ctx);
3094 #else
3095                                 syntax_err();
3096                                 return 1;
3097 #endif
3098                         }
3099                         break;
3100 #ifndef __U_BOOT__
3101                 case '(':
3102                 case '{':
3103                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3104                         break;
3105                 case ')':
3106                 case '}':
3107                         syntax();   /* Proper use of this character caught by end_trigger */
3108                         return 1;
3109                         break;
3110 #endif
3111                 default:
3112                         syntax();   /* this is really an internal logic error */
3113                         return 1;
3114                         }
3115                 }
3116         }
3117         /* complain if quote?  No, maybe we just finished a command substitution
3118          * that was quoted.  Example:
3119          * $ echo "`cat foo` plus more"
3120          * and we just got the EOF generated by the subshell that ran "cat foo"
3121          * The only real complaint is if we got an EOF when end_trigger != '\0',
3122          * that is, we were really supposed to get end_trigger, and never got
3123          * one before the EOF.  Can't use the standard "syntax error" return code,
3124          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3125         debug_printf("leaving parse_stream (EOF)\n");
3126         if (end_trigger != '\0') return -1;
3127         return 0;
3128 }
3129
3130 void mapset(const unsigned char *set, int code)
3131 {
3132         const unsigned char *s;
3133         for (s=set; *s; s++) map[*s] = code;
3134 }
3135
3136 void update_ifs_map(void)
3137 {
3138         /* char *ifs and char map[256] are both globals. */
3139         ifs = (uchar *)getenv("IFS");
3140         if (ifs == NULL) ifs=(uchar *)" \t\n";
3141         /* Precompute a list of 'flow through' behavior so it can be treated
3142          * quickly up front.  Computation is necessary because of IFS.
3143          * Special case handling of IFS == " \t\n" is not implemented.
3144          * The map[] array only really needs two bits each, and on most machines
3145          * that would be faster because of the reduced L1 cache footprint.
3146          */
3147         memset(map,0,sizeof(map)); /* most characters flow through always */
3148 #ifndef __U_BOOT__
3149         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3150         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3151 #else
3152         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3153         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3154 #endif
3155         mapset(ifs, 2);            /* also flow through if quoted */
3156 }
3157
3158 /* most recursion does not come through here, the exeception is
3159  * from builtin_source() */
3160 int parse_stream_outer(struct in_str *inp, int flag)
3161 {
3162
3163         struct p_context ctx;
3164         o_string temp=NULL_O_STRING;
3165         int rcode;
3166 #ifdef __U_BOOT__
3167         int code = 0;
3168 #endif
3169         do {
3170                 ctx.type = flag;
3171                 initialize_context(&ctx);
3172                 update_ifs_map();
3173                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3174                 inp->promptmode=1;
3175                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3176 #ifdef __U_BOOT__
3177                 if (rcode == 1) flag_repeat = 0;
3178 #endif
3179                 if (rcode != 1 && ctx.old_flag != 0) {
3180                         syntax();
3181 #ifdef __U_BOOT__
3182                         flag_repeat = 0;
3183 #endif
3184                 }
3185                 if (rcode != 1 && ctx.old_flag == 0) {
3186                         done_word(&temp, &ctx);
3187                         done_pipe(&ctx,PIPE_SEQ);
3188 #ifndef __U_BOOT__
3189                         run_list(ctx.list_head);
3190 #else
3191                         code = run_list(ctx.list_head);
3192                         if (code == -2) {       /* exit */
3193                                 b_free(&temp);
3194                                 code = 0;
3195                                 /* XXX hackish way to not allow exit from main loop */
3196                                 if (inp->peek == file_peek) {
3197                                         printf("exit not allowed from main input shell.\n");
3198                                         continue;
3199                                 }
3200                                 break;
3201                         }
3202                         if (code == -1)
3203                             flag_repeat = 0;
3204 #endif
3205                 } else {
3206                         if (ctx.old_flag != 0) {
3207                                 free(ctx.stack);
3208                                 b_reset(&temp);
3209                         }
3210 #ifdef __U_BOOT__
3211                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3212                         inp->__promptme = 1;
3213 #endif
3214                         temp.nonnull = 0;
3215                         temp.quote = 0;
3216                         inp->p = NULL;
3217                         free_pipe_list(ctx.list_head,0);
3218                 }
3219                 b_free(&temp);
3220         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3221 #ifndef __U_BOOT__
3222         return 0;
3223 #else
3224         return (code != 0) ? 1 : 0;
3225 #endif /* __U_BOOT__ */
3226 }
3227
3228 #ifndef __U_BOOT__
3229 static int parse_string_outer(const char *s, int flag)
3230 #else
3231 int parse_string_outer(char *s, int flag)
3232 #endif  /* __U_BOOT__ */
3233 {
3234         struct in_str input;
3235 #ifdef __U_BOOT__
3236         char *p = NULL;
3237         int rcode;
3238         if ( !s || !*s)
3239                 return 1;
3240         if (!(p = strchr(s, '\n')) || *++p) {
3241                 p = xmalloc(strlen(s) + 2);
3242                 strcpy(p, s);
3243                 strcat(p, "\n");
3244                 setup_string_in_str(&input, p);
3245                 rcode = parse_stream_outer(&input, flag);
3246                 free(p);
3247                 return rcode;
3248         } else {
3249 #endif
3250         setup_string_in_str(&input, s);
3251         return parse_stream_outer(&input, flag);
3252 #ifdef __U_BOOT__
3253         }
3254 #endif
3255 }
3256
3257 #ifndef __U_BOOT__
3258 static int parse_file_outer(FILE *f)
3259 #else
3260 int parse_file_outer(void)
3261 #endif
3262 {
3263         int rcode;
3264         struct in_str input;
3265 #ifndef __U_BOOT__
3266         setup_file_in_str(&input, f);
3267 #else
3268         setup_file_in_str(&input);
3269 #endif
3270         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3271         return rcode;
3272 }
3273
3274 #ifdef __U_BOOT__
3275 static void u_boot_hush_reloc(void)
3276 {
3277         unsigned long addr;
3278         struct reserved_combo *r;
3279
3280         for (r=reserved_list; r<reserved_list+NRES; r++) {
3281                 addr = (ulong) (r->literal) + gd->reloc_off;
3282                 r->literal = (char *)addr;
3283         }
3284 }
3285
3286 int u_boot_hush_start(void)
3287 {
3288         if (top_vars == NULL) {
3289                 top_vars = malloc(sizeof(struct variables));
3290                 top_vars->name = "HUSH_VERSION";
3291                 top_vars->value = "0.01";
3292                 top_vars->next = 0;
3293                 top_vars->flg_export = 0;
3294                 top_vars->flg_read_only = 1;
3295                 u_boot_hush_reloc();
3296         }
3297         return 0;
3298 }
3299
3300 static void *xmalloc(size_t size)
3301 {
3302         void *p = NULL;
3303
3304         if (!(p = malloc(size))) {
3305             printf("ERROR : memory not allocated\n");
3306             for(;;);
3307         }
3308         return p;
3309 }
3310
3311 static void *xrealloc(void *ptr, size_t size)
3312 {
3313         void *p = NULL;
3314
3315         if (!(p = realloc(ptr, size))) {
3316             printf("ERROR : memory not allocated\n");
3317             for(;;);
3318         }
3319         return p;
3320 }
3321 #endif /* __U_BOOT__ */
3322
3323 #ifndef __U_BOOT__
3324 /* Make sure we have a controlling tty.  If we get started under a job
3325  * aware app (like bash for example), make sure we are now in charge so
3326  * we don't fight over who gets the foreground */
3327 static void setup_job_control(void)
3328 {
3329         static pid_t shell_pgrp;
3330         /* Loop until we are in the foreground.  */
3331         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3332                 kill (- shell_pgrp, SIGTTIN);
3333
3334         /* Ignore interactive and job-control signals.  */
3335         signal(SIGINT, SIG_IGN);
3336         signal(SIGQUIT, SIG_IGN);
3337         signal(SIGTERM, SIG_IGN);
3338         signal(SIGTSTP, SIG_IGN);
3339         signal(SIGTTIN, SIG_IGN);
3340         signal(SIGTTOU, SIG_IGN);
3341         signal(SIGCHLD, SIG_IGN);
3342
3343         /* Put ourselves in our own process group.  */
3344         setsid();
3345         shell_pgrp = getpid ();
3346         setpgid (shell_pgrp, shell_pgrp);
3347
3348         /* Grab control of the terminal.  */
3349         tcsetpgrp(shell_terminal, shell_pgrp);
3350 }
3351
3352 int hush_main(int argc, char **argv)
3353 {
3354         int opt;
3355         FILE *input;
3356         char **e = environ;
3357
3358         /* XXX what should these be while sourcing /etc/profile? */
3359         global_argc = argc;
3360         global_argv = argv;
3361
3362         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3363          * hush_main(), therefore we cannot rely on the BSS to zero out this
3364          * stuff.  Reset these to 0 every time. */
3365         ifs = NULL;
3366         /* map[] is taken care of with call to update_ifs_map() */
3367         fake_mode = 0;
3368         interactive = 0;
3369         close_me_head = NULL;
3370         last_bg_pid = 0;
3371         job_list = NULL;
3372         last_jobid = 0;
3373
3374         /* Initialize some more globals to non-zero values */
3375         set_cwd();
3376 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3377         cmdedit_set_initial_prompt();
3378 #else
3379         PS1 = NULL;
3380 #endif
3381         PS2 = "> ";
3382
3383         /* initialize our shell local variables with the values
3384          * currently living in the environment */
3385         if (e) {
3386                 for (; *e; e++)
3387                         set_local_var(*e, 2);   /* without call putenv() */
3388         }
3389
3390         last_return_code=EXIT_SUCCESS;
3391
3392
3393         if (argv[0] && argv[0][0] == '-') {
3394                 debug_printf("\nsourcing /etc/profile\n");
3395                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3396                         mark_open(fileno(input));
3397                         parse_file_outer(input);
3398                         mark_closed(fileno(input));
3399                         fclose(input);
3400                 }
3401         }
3402         input=stdin;
3403
3404         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3405                 switch (opt) {
3406                         case 'c':
3407                                 {
3408                                         global_argv = argv+optind;
3409                                         global_argc = argc-optind;
3410                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3411                                         goto final_return;
3412                                 }
3413                                 break;
3414                         case 'i':
3415                                 interactive++;
3416                                 break;
3417                         case 'f':
3418                                 fake_mode++;
3419                                 break;
3420                         default:
3421 #ifndef BB_VER
3422                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3423                                                 "   or: sh -c command [args]...\n\n");
3424                                 exit(EXIT_FAILURE);
3425 #else
3426                                 show_usage();
3427 #endif
3428                 }
3429         }
3430         /* A shell is interactive if the `-i' flag was given, or if all of
3431          * the following conditions are met:
3432          *        no -c command
3433          *    no arguments remaining or the -s flag given
3434          *    standard input is a terminal
3435          *    standard output is a terminal
3436          *    Refer to Posix.2, the description of the `sh' utility. */
3437         if (argv[optind]==NULL && input==stdin &&
3438                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3439                 interactive++;
3440         }
3441
3442         debug_printf("\ninteractive=%d\n", interactive);
3443         if (interactive) {
3444                 /* Looks like they want an interactive shell */
3445 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3446                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3447                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3448 #endif
3449                 setup_job_control();
3450         }
3451
3452         if (argv[optind]==NULL) {
3453                 opt=parse_file_outer(stdin);
3454                 goto final_return;
3455         }
3456
3457         debug_printf("\nrunning script '%s'\n", argv[optind]);
3458         global_argv = argv+optind;
3459         global_argc = argc-optind;
3460         input = xfopen(argv[optind], "r");
3461         opt = parse_file_outer(input);
3462
3463 #ifdef CONFIG_FEATURE_CLEAN_UP
3464         fclose(input);
3465         if (cwd && cwd != unknown)
3466                 free((char*)cwd);
3467         {
3468                 struct variables *cur, *tmp;
3469                 for(cur = top_vars; cur; cur = tmp) {
3470                         tmp = cur->next;
3471                         if (!cur->flg_read_only) {
3472                                 free(cur->name);
3473                                 free(cur->value);
3474                                 free(cur);
3475                         }
3476                 }
3477         }
3478 #endif
3479
3480 final_return:
3481         return(opt?opt:last_return_code);
3482 }
3483 #endif
3484
3485 static char *insert_var_value(char *inp)
3486 {
3487         int res_str_len = 0;
3488         int len;
3489         int done = 0;
3490         char *p, *p1, *res_str = NULL;
3491
3492         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3493                 if (p != inp) {
3494                         len = p - inp;
3495                         res_str = xrealloc(res_str, (res_str_len + len));
3496                         strncpy((res_str + res_str_len), inp, len);
3497                         res_str_len += len;
3498                 }
3499                 inp = ++p;
3500                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3501                 *p = '\0';
3502                 if ((p1 = lookup_param(inp))) {
3503                         len = res_str_len + strlen(p1);
3504                         res_str = xrealloc(res_str, (1 + len));
3505                         strcpy((res_str + res_str_len), p1);
3506                         res_str_len = len;
3507                 }
3508                 *p = SPECIAL_VAR_SYMBOL;
3509                 inp = ++p;
3510                 done = 1;
3511         }
3512         if (done) {
3513                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3514                 strcpy((res_str + res_str_len), inp);
3515                 while ((p = strchr(res_str, '\n'))) {
3516                         *p = ' ';
3517                 }
3518         }
3519         return (res_str == NULL) ? inp : res_str;
3520 }
3521
3522 static char **make_list_in(char **inp, char *name)
3523 {
3524         int len, i;
3525         int name_len = strlen(name);
3526         int n = 0;
3527         char **list;
3528         char *p1, *p2, *p3;
3529
3530         /* create list of variable values */
3531         list = xmalloc(sizeof(*list));
3532         for (i = 0; inp[i]; i++) {
3533                 p3 = insert_var_value(inp[i]);
3534                 p1 = p3;
3535                 while (*p1) {
3536                         if ((*p1 == ' ')) {
3537                                 p1++;
3538                                 continue;
3539                         }
3540                         if ((p2 = strchr(p1, ' '))) {
3541                                 len = p2 - p1;
3542                         } else {
3543                                 len = strlen(p1);
3544                                 p2 = p1 + len;
3545                         }
3546                         /* we use n + 2 in realloc for list,because we add
3547                          * new element and then we will add NULL element */
3548                         list = xrealloc(list, sizeof(*list) * (n + 2));
3549                         list[n] = xmalloc(2 + name_len + len);
3550                         strcpy(list[n], name);
3551                         strcat(list[n], "=");
3552                         strncat(list[n], p1, len);
3553                         list[n++][name_len + len + 1] = '\0';
3554                         p1 = p2;
3555                 }
3556                 if (p3 != inp[i]) free(p3);
3557         }
3558         list[n] = NULL;
3559         return list;
3560 }
3561
3562 /* Make new string for parser */
3563 static char * make_string(char ** inp)
3564 {
3565         char *p;
3566         char *str = NULL;
3567         int n;
3568         int len = 2;
3569
3570         for (n = 0; inp[n]; n++) {
3571                 p = insert_var_value(inp[n]);
3572                 str = xrealloc(str, (len + strlen(p)));
3573                 if (n) {
3574                         strcat(str, " ");
3575                 } else {
3576                         *str = '\0';
3577                 }
3578                 strcat(str, p);
3579                 len = strlen(str) + 3;
3580                 if (p != inp[n]) free(p);
3581         }
3582         len = strlen(str);
3583         *(str + len) = '\n';
3584         *(str + len + 1) = '\0';
3585         return str;
3586 }
3587
3588 #endif /* CFG_HUSH_PARSER */
3589 /****************************************************************************/