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