common/hush.c

   1 /*
   2  * sh.c -- a prototype Bourne shell grammar parser
   3  *      Intended to follow the original Thompson and Ritchie
   4  *      "small and simple is beautiful" philosophy, which
   5  *      incidentally is a good match to today's BusyBox.
   6  *
   7  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   8  *
   9  * Credits:
  10  *      The parser routines proper are all original material, first
  11  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  12  *      The execution engine, the builtins, and much of the underlying
  13  *      support has been adapted from busybox-0.49pre's lash,
  14  *      which is Copyright (C) 2000 by Lineo, Inc., and
  15  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  16  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  17  *      Erik W. Troan, which they placed in the public domain.  I don't know
  18  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  19  * Other credits:
  20  *      simple_itoa() was lifted from boa-0.93.15
  21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  23  *        and many builtins derived from contributions by Erik Andersen
  24  *      miscellaneous bugfixes from Matt Kraai
  25  *
  26  * There are two big (and related) architecture differences between
  27  * this parser and the lash parser.  One is that this version is
  28  * actually designed from the ground up to understand nearly all
  29  * of the Bourne grammar.  The second, consequential change is that
  30  * the parser and input reader have been turned inside out.  Now,
  31  * the parser is in control, and asks for input as needed.  The old
  32  * way had the input reader in control, and it asked for parsing to
  33  * take place as needed.  The new way makes it much easier to properly
  34  * handle the recursion implicit in the various substitutions, especially
  35  * across continuation lines.
  36  *
  37  * Bash grammar not implemented: (how many of these were in original sh?)
  38  *      $@ (those sure look like weird quoting rules)
  39  *      $_
  40  *      ! negation operator for pipes
  41  *      &> and >& redirection of stdout+stderr
  42  *      Brace Expansion
  43  *      Tilde Expansion
  44  *      fancy forms of Parameter Expansion
  45  *      aliases
  46  *      Arithmetic Expansion
  47  *      <(list) and >(list) Process Substitution
  48  *      reserved words: case, esac, select, function
  49  *      Here Documents ( << word )
  50  *      Functions
  51  * Major bugs:
  52  *      job handling woefully incomplete and buggy
  53  *      reserved word execution woefully incomplete and buggy
  54  * to-do:
  55  *      port selected bugfixes from post-0.49 busybox lash - done?
  56  *      finish implementing reserved words: for, while, until, do, done
  57  *      change { and } from special chars to reserved words
  58  *      builtins: break, continue, eval, return, set, trap, ulimit
  59  *      test magic exec
  60  *      handle children going into background
  61  *      clean up recognition of null pipes
  62  *      check setting of global_argc and global_argv
  63  *      control-C handling, probably with longjmp
  64  *      follow IFS rules more precisely, including update semantics
  65  *      figure out what to do with backslash-newline
  66  *      explain why we use signal instead of sigaction
  67  *      propagate syntax errors, die on resource errors?
  68  *      continuation lines, both explicit and implicit - done?
  69  *      memory leak finding and plugging - done?
  70  *      more testing, especially quoting rules and redirection
  71  *      document how quoting rules not precisely followed for variable assignments
  72  *      maybe change map[] to use 2-bit entries
  73  *      (eventually) remove all the printf's
  74  *
  75  * This program is free software; you can redistribute it and/or modify
  76  * it under the terms of the GNU General Public License as published by
  77  * the Free Software Foundation; either version 2 of the License, or
  78  * (at your option) any later version.
  79  *
  80  * This program is distributed in the hope that it will be useful,
  81  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  82  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  83  * General Public License for more details.
  84  *
  85  * You should have received a copy of the GNU General Public License
  86  * along with this program; if not, write to the Free Software
  87  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  88  */
  89 #define __U_BOOT__
  90 #ifdef __U_BOOT__
  91 #include <malloc.h>         /* malloc, free, realloc*/
  92 #include <linux/ctype.h>    /* isalpha, isdigit */
  93 #include <common.h>        /* readline */
  94 #include <hush.h>
  95 #include <command.h>        /* find_cmd */
  96 /*cmd_boot.c*/
  97 extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);      /* do_bootd */
  98 #endif
  99 #ifdef CFG_HUSH_PARSER
 100 #ifndef __U_BOOT__
 101 #include <ctype.h>     /* isalpha, isdigit */
 102 #include <unistd.h>    /* getpid */
 103 #include <stdlib.h>    /* getenv, atoi */
 104 #include <string.h>    /* strchr */
 105 #include <stdio.h>     /* popen etc. */
 106 #include <glob.h>      /* glob, of course */
 107 #include <stdarg.h>    /* va_list */
 108 #include <errno.h>
 109 #include <fcntl.h>
 110 #include <getopt.h>    /* should be pretty obvious */
 111
 112 #include <sys/stat.h>  /* ulimit */
 113 #include <sys/types.h>
 114 #include <sys/wait.h>
 115 #include <signal.h>
 116
 117 /* #include <dmalloc.h> */
 118
 119 #if 1
 120 #include "busybox.h"
 121 #include "cmdedit.h"
 122 #else
 123 #define applet_name "hush"
 124 #include "standalone.h"
 125 #define hush_main main
 126 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 127 #define BB_BANNER
 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 DECLARE_GLOBAL_DATA_PTR;
 140
 141 #define EXIT_SUCCESS 0
 142 #define EOF -1
 143 #define syntax() syntax_err()
 144 #define xstrdup strdup
 145 #define error_msg printf
 146 #else
 147 typedef enum {
 148         REDIRECT_INPUT     = 1,
 149         REDIRECT_OVERWRITE = 2,
 150         REDIRECT_APPEND    = 3,
 151         REDIRECT_HEREIS    = 4,
 152         REDIRECT_IO        = 5
 153 } redir_type;
 154
 155 /* The descrip member of this structure is only used to make debugging
 156  * output pretty */
 157 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 158         { 0,                         0, "()" },
 159         { O_RDONLY,                  0, "<"  },
 160         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 161         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 162         { O_RDONLY,                 -1, "<<" },
 163         { O_RDWR,                    1, "<>" }
 164 };
 165 #endif
 166
 167 typedef enum {
 168         PIPE_SEQ = 1,
 169         PIPE_AND = 2,
 170         PIPE_OR  = 3,
 171         PIPE_BG  = 4,
 172 } pipe_style;
 173
 174 /* might eventually control execution */
 175 typedef enum {
 176         RES_NONE  = 0,
 177         RES_IF    = 1,
 178         RES_THEN  = 2,
 179         RES_ELIF  = 3,
 180         RES_ELSE  = 4,
 181         RES_FI    = 5,
 182         RES_FOR   = 6,
 183         RES_WHILE = 7,
 184         RES_UNTIL = 8,
 185         RES_DO    = 9,
 186         RES_DONE  = 10,
 187         RES_XXXX  = 11,
 188         RES_IN    = 12,
 189         RES_SNTX  = 13
 190 } reserved_style;
 191 #define FLAG_END   (1<<RES_NONE)
 192 #define FLAG_IF    (1<<RES_IF)
 193 #define FLAG_THEN  (1<<RES_THEN)
 194 #define FLAG_ELIF  (1<<RES_ELIF)
 195 #define FLAG_ELSE  (1<<RES_ELSE)
 196 #define FLAG_FI    (1<<RES_FI)
 197 #define FLAG_FOR   (1<<RES_FOR)
 198 #define FLAG_WHILE (1<<RES_WHILE)
 199 #define FLAG_UNTIL (1<<RES_UNTIL)
 200 #define FLAG_DO    (1<<RES_DO)
 201 #define FLAG_DONE  (1<<RES_DONE)
 202 #define FLAG_IN    (1<<RES_IN)
 203 #define FLAG_START (1<<RES_XXXX)
 204
 205 /* This holds pointers to the various results of parsing */
 206 struct p_context {
 207         struct child_prog *child;
 208         struct pipe *list_head;
 209         struct pipe *pipe;
 210 #ifndef __U_BOOT__
 211         struct redir_struct *pending_redirect;
 212 #endif
 213         reserved_style w;
 214         int old_flag;                           /* for figuring out valid reserved words */
 215         struct p_context *stack;
 216         int type;                       /* define type of parser : ";$" common or special symbol */
 217         /* How about quoting status? */
 218 };
 219
 220 #ifndef __U_BOOT__
 221 struct redir_struct {
 222         redir_type type;                        /* type of redirection */
 223         int fd;                                         /* file descriptor being redirected */
 224         int dup;                                        /* -1, or file descriptor being duplicated */
 225         struct redir_struct *next;      /* pointer to the next redirect in the list */
 226         glob_t word;                            /* *word.gl_pathv is the filename */
 227 };
 228 #endif
 229
 230 struct child_prog {
 231 #ifndef __U_BOOT__
 232         pid_t pid;                                      /* 0 if exited */
 233 #endif
 234         char **argv;                            /* program name and arguments */
 235 #ifdef __U_BOOT__
 236         int    argc;                            /* number of program arguments */
 237 #endif
 238         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 239 #ifndef __U_BOOT__
 240         int subshell;                           /* flag, non-zero if group must be forked */
 241         struct redir_struct *redirects; /* I/O redirections */
 242         glob_t glob_result;                     /* result of parameter globbing */
 243         int is_stopped;                         /* is the program currently running? */
 244         struct pipe *family;            /* pointer back to the child's parent pipe */
 245 #endif
 246         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 247         int type;
 248 };
 249
 250 struct pipe {
 251 #ifndef __U_BOOT__
 252         int jobid;                                      /* job number */
 253 #endif
 254         int num_progs;                          /* total number of programs in job */
 255 #ifndef __U_BOOT__
 256         int running_progs;                      /* number of programs running */
 257         char *text;                                     /* name of job */
 258         char *cmdbuf;                           /* buffer various argv's point into */
 259         pid_t pgrp;                                     /* process group ID for the job */
 260 #endif
 261         struct child_prog *progs;       /* array of commands in pipe */
 262         struct pipe *next;                      /* to track background commands */
 263 #ifndef __U_BOOT__
 264         int stopped_progs;                      /* number of programs alive, but stopped */
 265         int job_context;                        /* bitmask defining current context */
 266 #endif
 267         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 268         reserved_style r_mode;          /* supports if, for, while, until */
 269 };
 270
 271 #ifndef __U_BOOT__
 272 struct close_me {
 273         int fd;
 274         struct close_me *next;
 275 };
 276 #endif
 277
 278 struct variables {
 279         char *name;
 280         char *value;
 281         int flg_export;
 282         int flg_read_only;
 283         struct variables *next;
 284 };
 285
 286 /* globals, connect us to the outside world
 287  * the first three support $?, $#, and $1 */
 288 #ifndef __U_BOOT__
 289 char **global_argv;
 290 unsigned int global_argc;
 291 #endif
 292 unsigned int last_return_code;
 293 int nesting_level;
 294 #ifndef __U_BOOT__
 295 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 296 #endif
 297
 298 /* "globals" within this file */
 299 static uchar *ifs;
 300 static char map[256];
 301 #ifndef __U_BOOT__
 302 static int fake_mode;
 303 static int interactive;
 304 static struct close_me *close_me_head;
 305 static const char *cwd;
 306 static struct pipe *job_list;
 307 static unsigned int last_bg_pid;
 308 static unsigned int last_jobid;
 309 static unsigned int shell_terminal;
 310 static char *PS1;
 311 static char *PS2;
 312 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 313 struct variables *top_vars = &shell_ver;
 314 #else
 315 static int flag_repeat = 0;
 316 static int do_repeat = 0;
 317 static struct variables *top_vars = NULL ;
 318 #endif /*__U_BOOT__ */
 319
 320 #define B_CHUNK (100)
 321 #define B_NOSPAC 1
 322
 323 typedef struct {
 324         char *data;
 325         int length;
 326         int maxlen;
 327         int quote;
 328         int nonnull;
 329 } o_string;
 330 #define NULL_O_STRING {NULL,0,0,0,0}
 331 /* used for initialization:
 332         o_string foo = NULL_O_STRING; */
 333
 334 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 335  * available?  Where is it documented? */
 336 struct in_str {
 337         const char *p;
 338 #ifndef __U_BOOT__
 339         char peek_buf[2];
 340 #endif
 341         int __promptme;
 342         int promptmode;
 343 #ifndef __U_BOOT__
 344         FILE *file;
 345 #endif
 346         int (*get) (struct in_str *);
 347         int (*peek) (struct in_str *);
 348 };
 349 #define b_getch(input) ((input)->get(input))
 350 #define b_peek(input) ((input)->peek(input))
 351
 352 #ifndef __U_BOOT__
 353 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 354
 355 struct built_in_command {
 356         char *cmd;                                      /* name */
 357         char *descr;                            /* description */
 358         int (*function) (struct child_prog *);  /* function ptr */
 359 };
 360 #endif
 361
 362 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 363 #if 0
 364 #define DEBUG_SHELL
 365 #endif
 366
 367 /* This should be in utility.c */
 368 #ifdef DEBUG_SHELL
 369 #ifndef __U_BOOT__
 370 static void debug_printf(const char *format, ...)
 371 {
 372         va_list args;
 373         va_start(args, format);
 374         vfprintf(stderr, format, args);
 375         va_end(args);
 376 }
 377 #else
 378 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 379 #endif
 380 #else
 381 static inline void debug_printf(const char *format, ...) { }
 382 #endif
 383 #define final_printf debug_printf
 384
 385 #ifdef __U_BOOT__
 386 static void syntax_err(void) {
 387          printf("syntax error\n");
 388 }
 389 #else
 390 static void __syntax(char *file, int line) {
 391         error_msg("syntax error %s:%d", file, line);
 392 }
 393 #define syntax() __syntax(__FILE__, __LINE__)
 394 #endif
 395
 396 #ifdef __U_BOOT__
 397 static void *xmalloc(size_t size);
 398 static void *xrealloc(void *ptr, size_t size);
 399 #else
 400 /* Index of subroutines: */
 401 /*   function prototypes for builtins */
 402 static int builtin_cd(struct child_prog *child);
 403 static int builtin_env(struct child_prog *child);
 404 static int builtin_eval(struct child_prog *child);
 405 static int builtin_exec(struct child_prog *child);
 406 static int builtin_exit(struct child_prog *child);
 407 static int builtin_export(struct child_prog *child);
 408 static int builtin_fg_bg(struct child_prog *child);
 409 static int builtin_help(struct child_prog *child);
 410 static int builtin_jobs(struct child_prog *child);
 411 static int builtin_pwd(struct child_prog *child);
 412 static int builtin_read(struct child_prog *child);
 413 static int builtin_set(struct child_prog *child);
 414 static int builtin_shift(struct child_prog *child);
 415 static int builtin_source(struct child_prog *child);
 416 static int builtin_umask(struct child_prog *child);
 417 static int builtin_unset(struct child_prog *child);
 418 static int builtin_not_written(struct child_prog *child);
 419 #endif
 420 /*   o_string manipulation: */
 421 static int b_check_space(o_string *o, int len);
 422 static int b_addchr(o_string *o, int ch);
 423 static void b_reset(o_string *o);
 424 static int b_addqchr(o_string *o, int ch, int quote);
 425 #ifndef __U_BOOT__
 426 static int b_adduint(o_string *o, unsigned int i);
 427 #endif
 428 /*  in_str manipulations: */
 429 static int static_get(struct in_str *i);
 430 static int static_peek(struct in_str *i);
 431 static int file_get(struct in_str *i);
 432 static int file_peek(struct in_str *i);
 433 #ifndef __U_BOOT__
 434 static void setup_file_in_str(struct in_str *i, FILE *f);
 435 #else
 436 static void setup_file_in_str(struct in_str *i);
 437 #endif
 438 static void setup_string_in_str(struct in_str *i, const char *s);
 439 #ifndef __U_BOOT__
 440 /*  close_me manipulations: */
 441 static void mark_open(int fd);
 442 static void mark_closed(int fd);
 443 static void close_all(void);
 444 #endif
 445 /*  "run" the final data structures: */
 446 static char *indenter(int i);
 447 static int free_pipe_list(struct pipe *head, int indent);
 448 static int free_pipe(struct pipe *pi, int indent);
 449 /*  really run the final data structures: */
 450 #ifndef __U_BOOT__
 451 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 452 #endif
 453 static int run_list_real(struct pipe *pi);
 454 #ifndef __U_BOOT__
 455 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 456 #endif
 457 static int run_pipe_real(struct pipe *pi);
 458 /*   extended glob support: */
 459 #ifndef __U_BOOT__
 460 static int globhack(const char *src, int flags, glob_t *pglob);
 461 static int glob_needed(const char *s);
 462 static int xglob(o_string *dest, int flags, glob_t *pglob);
 463 #endif
 464 /*   variable assignment: */
 465 static int is_assignment(const char *s);
 466 /*   data structure manipulation: */
 467 #ifndef __U_BOOT__
 468 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 469 #endif
 470 static void initialize_context(struct p_context *ctx);
 471 static int done_word(o_string *dest, struct p_context *ctx);
 472 static int done_command(struct p_context *ctx);
 473 static int done_pipe(struct p_context *ctx, pipe_style type);
 474 /*   primary string parsing: */
 475 #ifndef __U_BOOT__
 476 static int redirect_dup_num(struct in_str *input);
 477 static int redirect_opt_num(o_string *o);
 478 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 479 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 480 #endif
 481 static char *lookup_param(char *src);
 482 static char *make_string(char **inp);
 483 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 484 #ifndef __U_BOOT__
 485 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 486 #endif
 487 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 488 /*   setup: */
 489 static int parse_stream_outer(struct in_str *inp, int flag);
 490 #ifndef __U_BOOT__
 491 static int parse_string_outer(const char *s, int flag);
 492 static int parse_file_outer(FILE *f);
 493 #endif
 494 #ifndef __U_BOOT__
 495 /*   job management: */
 496 static int checkjobs(struct pipe* fg_pipe);
 497 static void insert_bg_job(struct pipe *pi);
 498 static void remove_bg_job(struct pipe *pi);
 499 #endif
 500 /*     local variable support */
 501 static char **make_list_in(char **inp, char *name);
 502 static char *insert_var_value(char *inp);
 503 static char *get_local_var(const char *var);
 504 #ifndef __U_BOOT__
 505 static void  unset_local_var(const char *name);
 506 #endif
 507 static int set_local_var(const char *s, int flg_export);
 508
 509 #ifndef __U_BOOT__
 510 /* Table of built-in functions.  They can be forked or not, depending on
 511  * context: within pipes, they fork.  As simple commands, they do not.
 512  * When used in non-forking context, they can change global variables
 513  * in the parent shell process.  If forked, of course they can not.
 514  * For example, 'unset foo | whatever' will parse and run, but foo will
 515  * still be set at the end. */
 516 static struct built_in_command bltins[] = {
 517         {"bg", "Resume a job in the background", builtin_fg_bg},
 518         {"break", "Exit for, while or until loop", builtin_not_written},
 519         {"cd", "Change working directory", builtin_cd},
 520         {"continue", "Continue for, while or until loop", builtin_not_written},
 521         {"env", "Print all environment variables", builtin_env},
 522         {"eval", "Construct and run shell command", builtin_eval},
 523         {"exec", "Exec command, replacing this shell with the exec'd process",
 524                 builtin_exec},
 525         {"exit", "Exit from shell()", builtin_exit},
 526         {"export", "Set environment variable", builtin_export},
 527         {"fg", "Bring job into the foreground", builtin_fg_bg},
 528         {"jobs", "Lists the active jobs", builtin_jobs},
 529         {"pwd", "Print current directory", builtin_pwd},
 530         {"read", "Input environment variable", builtin_read},
 531         {"return", "Return from a function", builtin_not_written},
 532         {"set", "Set/unset shell local variables", builtin_set},
 533         {"shift", "Shift positional parameters", builtin_shift},
 534         {"trap", "Trap signals", builtin_not_written},
 535         {"ulimit","Controls resource limits", builtin_not_written},
 536         {"umask","Sets file creation mask", builtin_umask},
 537         {"unset", "Unset environment variable", builtin_unset},
 538         {".", "Source-in and run commands in a file", builtin_source},
 539         {"help", "List shell built-in commands", builtin_help},
 540         {NULL, NULL, NULL}
 541 };
 542
 543 static const char *set_cwd(void)
 544 {
 545         if(cwd==unknown)
 546                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 547         cwd = xgetcwd((char *)cwd);
 548         if (!cwd)
 549                 cwd = unknown;
 550         return cwd;
 551 }
 552
 553 /* built-in 'eval' handler */
 554 static int builtin_eval(struct child_prog *child)
 555 {
 556         char *str = NULL;
 557         int rcode = EXIT_SUCCESS;
 558
 559         if (child->argv[1]) {
 560                 str = make_string(child->argv + 1);
 561                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 562                                         FLAG_PARSE_SEMICOLON);
 563                 free(str);
 564                 rcode = last_return_code;
 565         }
 566         return rcode;
 567 }
 568
 569 /* built-in 'cd <path>' handler */
 570 static int builtin_cd(struct child_prog *child)
 571 {
 572         char *newdir;
 573         if (child->argv[1] == NULL)
 574                 newdir = getenv("HOME");
 575         else
 576                 newdir = child->argv[1];
 577         if (chdir(newdir)) {
 578                 printf("cd: %s: %s\n", newdir, strerror(errno));
 579                 return EXIT_FAILURE;
 580         }
 581         set_cwd();
 582         return EXIT_SUCCESS;
 583 }
 584
 585 /* built-in 'env' handler */
 586 static int builtin_env(struct child_prog *dummy)
 587 {
 588         char **e = environ;
 589         if (e == NULL) return EXIT_FAILURE;
 590         for (; *e; e++) {
 591                 puts(*e);
 592         }
 593         return EXIT_SUCCESS;
 594 }
 595
 596 /* built-in 'exec' handler */
 597 static int builtin_exec(struct child_prog *child)
 598 {
 599         if (child->argv[1] == NULL)
 600                 return EXIT_SUCCESS;   /* Really? */
 601         child->argv++;
 602         pseudo_exec(child);
 603         /* never returns */
 604 }
 605
 606 /* built-in 'exit' handler */
 607 static int builtin_exit(struct child_prog *child)
 608 {
 609         if (child->argv[1] == NULL)
 610                 exit(last_return_code);
 611         exit (atoi(child->argv[1]));
 612 }
 613
 614 /* built-in 'export VAR=value' handler */
 615 static int builtin_export(struct child_prog *child)
 616 {
 617         int res = 0;
 618         char *name = child->argv[1];
 619
 620         if (name == NULL) {
 621                 return (builtin_env(child));
 622         }
 623
 624         name = strdup(name);
 625
 626         if(name) {
 627                 char *value = strchr(name, '=');
 628
 629                 if (!value) {
 630                         char *tmp;
 631                         /* They are exporting something without an =VALUE */
 632
 633                         value = get_local_var(name);
 634                         if (value) {
 635                                 size_t ln = strlen(name);
 636
 637                                 tmp = realloc(name, ln+strlen(value)+2);
 638                                 if(tmp==NULL)
 639                                         res = -1;
 640                                 else {
 641                                         sprintf(tmp+ln, "=%s", value);
 642                                         name = tmp;
 643                                 }
 644                         } else {
 645                                 /* bash does not return an error when trying to export
 646                                  * an undefined variable.  Do likewise. */
 647                                 res = 1;
 648                         }
 649                 }
 650         }
 651         if (res<0)
 652                 perror_msg("export");
 653         else if(res==0)
 654                 res = set_local_var(name, 1);
 655         else
 656                 res = 0;
 657         free(name);
 658         return res;
 659 }
 660
 661 /* built-in 'fg' and 'bg' handler */
 662 static int builtin_fg_bg(struct child_prog *child)
 663 {
 664         int i, jobnum;
 665         struct pipe *pi=NULL;
 666
 667         if (!interactive)
 668                 return EXIT_FAILURE;
 669         /* If they gave us no args, assume they want the last backgrounded task */
 670         if (!child->argv[1]) {
 671                 for (pi = job_list; pi; pi = pi->next) {
 672                         if (pi->jobid == last_jobid) {
 673                                 break;
 674                         }
 675                 }
 676                 if (!pi) {
 677                         error_msg("%s: no current job", child->argv[0]);
 678                         return EXIT_FAILURE;
 679                 }
 680         } else {
 681                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 682                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 683                         return EXIT_FAILURE;
 684                 }
 685                 for (pi = job_list; pi; pi = pi->next) {
 686                         if (pi->jobid == jobnum) {
 687                                 break;
 688                         }
 689                 }
 690                 if (!pi) {
 691                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 692                         return EXIT_FAILURE;
 693                 }
 694         }
 695
 696         if (*child->argv[0] == 'f') {
 697                 /* Put the job into the foreground.  */
 698                 tcsetpgrp(shell_terminal, pi->pgrp);
 699         }
 700
 701         /* Restart the processes in the job */
 702         for (i = 0; i < pi->num_progs; i++)
 703                 pi->progs[i].is_stopped = 0;
 704
 705         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 706                 if (i == ESRCH) {
 707                         remove_bg_job(pi);
 708                 } else {
 709                         perror_msg("kill (SIGCONT)");
 710                 }
 711         }
 712
 713         pi->stopped_progs = 0;
 714         return EXIT_SUCCESS;
 715 }
 716
 717 /* built-in 'help' handler */
 718 static int builtin_help(struct child_prog *dummy)
 719 {
 720         struct built_in_command *x;
 721
 722         printf("\nBuilt-in commands:\n");
 723         printf("-------------------\n");
 724         for (x = bltins; x->cmd; x++) {
 725                 if (x->descr==NULL)
 726                         continue;
 727                 printf("%s\t%s\n", x->cmd, x->descr);
 728         }
 729         printf("\n\n");
 730         return EXIT_SUCCESS;
 731 }
 732
 733 /* built-in 'jobs' handler */
 734 static int builtin_jobs(struct child_prog *child)
 735 {
 736         struct pipe *job;
 737         char *status_string;
 738
 739         for (job = job_list; job; job = job->next) {
 740                 if (job->running_progs == job->stopped_progs)
 741                         status_string = "Stopped";
 742                 else
 743                         status_string = "Running";
 744
 745                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 746         }
 747         return EXIT_SUCCESS;
 748 }
 749
 750
 751 /* built-in 'pwd' handler */
 752 static int builtin_pwd(struct child_prog *dummy)
 753 {
 754         puts(set_cwd());
 755         return EXIT_SUCCESS;
 756 }
 757
 758 /* built-in 'read VAR' handler */
 759 static int builtin_read(struct child_prog *child)
 760 {
 761         int res;
 762
 763         if (child->argv[1]) {
 764                 char string[BUFSIZ];
 765                 char *var = 0;
 766
 767                 string[0] = 0;  /* In case stdin has only EOF */
 768                 /* read string */
 769                 fgets(string, sizeof(string), stdin);
 770                 chomp(string);
 771                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 772                 if(var) {
 773                         sprintf(var, "%s=%s", child->argv[1], string);
 774                         res = set_local_var(var, 0);
 775                 } else
 776                         res = -1;
 777                 if (res)
 778                         fprintf(stderr, "read: %m\n");
 779                 free(var);      /* So not move up to avoid breaking errno */
 780                 return res;
 781         } else {
 782                 do res=getchar(); while(res!='\n' && res!=EOF);
 783                 return 0;
 784         }
 785 }
 786
 787 /* built-in 'set VAR=value' handler */
 788 static int builtin_set(struct child_prog *child)
 789 {
 790         char *temp = child->argv[1];
 791         struct variables *e;
 792
 793         if (temp == NULL)
 794                 for(e = top_vars; e; e=e->next)
 795                         printf("%s=%s\n", e->name, e->value);
 796         else
 797                 set_local_var(temp, 0);
 798
 799                 return EXIT_SUCCESS;
 800 }
 801
 802
 803 /* Built-in 'shift' handler */
 804 static int builtin_shift(struct child_prog *child)
 805 {
 806         int n=1;
 807         if (child->argv[1]) {
 808                 n=atoi(child->argv[1]);
 809         }
 810         if (n>=0 && n<global_argc) {
 811                 /* XXX This probably breaks $0 */
 812                 global_argc -= n;
 813                 global_argv += n;
 814                 return EXIT_SUCCESS;
 815         } else {
 816                 return EXIT_FAILURE;
 817         }
 818 }
 819
 820 /* Built-in '.' handler (read-in and execute commands from file) */
 821 static int builtin_source(struct child_prog *child)
 822 {
 823         FILE *input;
 824         int status;
 825
 826         if (child->argv[1] == NULL)
 827                 return EXIT_FAILURE;
 828
 829         /* XXX search through $PATH is missing */
 830         input = fopen(child->argv[1], "r");
 831         if (!input) {
 832                 error_msg("Couldn't open file '%s'", child->argv[1]);
 833                 return EXIT_FAILURE;
 834         }
 835
 836         /* Now run the file */
 837         /* XXX argv and argc are broken; need to save old global_argv
 838          * (pointer only is OK!) on this stack frame,
 839          * set global_argv=child->argv+1, recurse, and restore. */
 840         mark_open(fileno(input));
 841         status = parse_file_outer(input);
 842         mark_closed(fileno(input));
 843         fclose(input);
 844         return (status);
 845 }
 846
 847 static int builtin_umask(struct child_prog *child)
 848 {
 849         mode_t new_umask;
 850         const char *arg = child->argv[1];
 851         char *end;
 852         if (arg) {
 853                 new_umask=strtoul(arg, &end, 8);
 854                 if (*end!='\0' || end == arg) {
 855                         return EXIT_FAILURE;
 856                 }
 857         } else {
 858                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 859         }
 860         umask(new_umask);
 861         return EXIT_SUCCESS;
 862 }
 863
 864 /* built-in 'unset VAR' handler */
 865 static int builtin_unset(struct child_prog *child)
 866 {
 867         /* bash returned already true */
 868         unset_local_var(child->argv[1]);
 869         return EXIT_SUCCESS;
 870 }
 871
 872 static int builtin_not_written(struct child_prog *child)
 873 {
 874         printf("builtin_%s not written\n",child->argv[0]);
 875         return EXIT_FAILURE;
 876 }
 877 #endif
 878
 879 static int b_check_space(o_string *o, int len)
 880 {
 881         /* It would be easy to drop a more restrictive policy
 882          * in here, such as setting a maximum string length */
 883         if (o->length + len > o->maxlen) {
 884                 char *old_data = o->data;
 885                 /* assert (data == NULL || o->maxlen != 0); */
 886                 o->maxlen += max(2*len, B_CHUNK);
 887                 o->data = realloc(o->data, 1 + o->maxlen);
 888                 if (o->data == NULL) {
 889                         free(old_data);
 890                 }
 891         }
 892         return o->data == NULL;
 893 }
 894
 895 static int b_addchr(o_string *o, int ch)
 896 {
 897         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 898         if (b_check_space(o, 1)) return B_NOSPAC;
 899         o->data[o->length] = ch;
 900         o->length++;
 901         o->data[o->length] = '\0';
 902         return 0;
 903 }
 904
 905 static void b_reset(o_string *o)
 906 {
 907         o->length = 0;
 908         o->nonnull = 0;
 909         if (o->data != NULL) *o->data = '\0';
 910 }
 911
 912 static void b_free(o_string *o)
 913 {
 914         b_reset(o);
 915         free(o->data);
 916         o->data = NULL;
 917         o->maxlen = 0;
 918 }
 919
 920 /* My analysis of quoting semantics tells me that state information
 921  * is associated with a destination, not a source.
 922  */
 923 static int b_addqchr(o_string *o, int ch, int quote)
 924 {
 925         if (quote && strchr("*?[\\",ch)) {
 926                 int rc;
 927                 rc = b_addchr(o, '\\');
 928                 if (rc) return rc;
 929         }
 930         return b_addchr(o, ch);
 931 }
 932
 933 /* belongs in utility.c */
 934 char *simple_itoa(unsigned int i)
 935 {
 936         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 937         static char local[22];
 938         char *p = &local[21];
 939         *p-- = '\0';
 940         do {
 941                 *p-- = '0' + i % 10;
 942                 i /= 10;
 943         } while (i > 0);
 944         return p + 1;
 945 }
 946
 947 #ifndef __U_BOOT__
 948 static int b_adduint(o_string *o, unsigned int i)
 949 {
 950         int r;
 951         char *p = simple_itoa(i);
 952         /* no escape checking necessary */
 953         do r=b_addchr(o, *p++); while (r==0 && *p);
 954         return r;
 955 }
 956 #endif
 957
 958 static int static_get(struct in_str *i)
 959 {
 960         int ch = *i->p++;
 961         if (ch=='\0') return EOF;
 962         return ch;
 963 }
 964
 965 static int static_peek(struct in_str *i)
 966 {
 967         return *i->p;
 968 }
 969
 970 #ifndef __U_BOOT__
 971 static inline void cmdedit_set_initial_prompt(void)
 972 {
 973 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 974         PS1 = NULL;
 975 #else
 976         PS1 = getenv("PS1");
 977         if(PS1==0)
 978                 PS1 = "\\w \\$ ";
 979 #endif
 980 }
 981
 982 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 983 {
 984         debug_printf("setup_prompt_string %d ",promptmode);
 985 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 986         /* Set up the prompt */
 987         if (promptmode == 1) {
 988                 free(PS1);
 989                 PS1=xmalloc(strlen(cwd)+4);
 990                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 991                 *prompt_str = PS1;
 992         } else {
 993                 *prompt_str = PS2;
 994         }
 995 #else
 996         *prompt_str = (promptmode==1)? PS1 : PS2;
 997 #endif
 998         debug_printf("result %s\n",*prompt_str);
 999 }
1000 #endif
1001
1002 static void get_user_input(struct in_str *i)
1003 {
1004 #ifndef __U_BOOT__
1005         char *prompt_str;
1006         static char the_command[BUFSIZ];
1007
1008         setup_prompt_string(i->promptmode, &prompt_str);
1009 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1010         /*
1011          ** enable command line editing only while a command line
1012          ** is actually being read; otherwise, we'll end up bequeathing
1013          ** atexit() handlers and other unwanted stuff to our
1014          ** child processes (rob@sysgo.de)
1015          */
1016         cmdedit_read_input(prompt_str, the_command);
1017 #else
1018         fputs(prompt_str, stdout);
1019         fflush(stdout);
1020         the_command[0]=fgetc(i->file);
1021         the_command[1]='\0';
1022 #endif
1023         fflush(stdout);
1024         i->p = the_command;
1025 #else
1026         extern char console_buffer[CFG_CBSIZE];
1027         int n;
1028         static char the_command[CFG_CBSIZE];
1029
1030 #ifdef CONFIG_BOOT_RETRY_TIME
1031 #  ifdef CONFIG_RESET_TO_RETRY
1032         extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1033 #  else
1034 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1035 #  endif
1036         reset_cmd_timeout();
1037 #endif
1038         i->__promptme = 1;
1039         if (i->promptmode == 1) {
1040                 n = readline(CFG_PROMPT);
1041         } else {
1042                 n = readline(CFG_PROMPT_HUSH_PS2);
1043         }
1044 #ifdef CONFIG_BOOT_RETRY_TIME
1045         if (n == -2) {
1046           puts("\nTimeout waiting for command\n");
1047 #  ifdef CONFIG_RESET_TO_RETRY
1048           do_reset(NULL, 0, 0, NULL);
1049 #  else
1050 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1051 #  endif
1052         }
1053 #endif
1054         if (n == -1 ) {
1055                 flag_repeat = 0;
1056                 i->__promptme = 0;
1057         }
1058         n = strlen(console_buffer);
1059         console_buffer[n] = '\n';
1060         console_buffer[n+1]= '\0';
1061         if (had_ctrlc()) flag_repeat = 0;
1062         clear_ctrlc();
1063         do_repeat = 0;
1064         if (i->promptmode == 1) {
1065                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1066                         strcpy(the_command,console_buffer);
1067                 }
1068                 else {
1069                         if (console_buffer[0] != '\n') {
1070                                 strcpy(the_command,console_buffer);
1071                                 flag_repeat = 1;
1072                         }
1073                         else {
1074                                 do_repeat = 1;
1075                         }
1076                 }
1077                 i->p = the_command;
1078         }
1079         else {
1080                 if (console_buffer[0] != '\n') {
1081                         if (strlen(the_command) + strlen(console_buffer)
1082                             < CFG_CBSIZE) {
1083                                 n = strlen(the_command);
1084                                 the_command[n-1] = ' ';
1085                                 strcpy(&the_command[n],console_buffer);
1086                         }
1087                         else {
1088                                 the_command[0] = '\n';
1089                                 the_command[1] = '\0';
1090                                 flag_repeat = 0;
1091                         }
1092                 }
1093                 if (i->__promptme == 0) {
1094                         the_command[0] = '\n';
1095                         the_command[1] = '\0';
1096                 }
1097                 i->p = console_buffer;
1098         }
1099 #endif
1100 }
1101
1102 /* This is the magic location that prints prompts
1103  * and gets data back from the user */
1104 static int file_get(struct in_str *i)
1105 {
1106         int ch;
1107
1108         ch = 0;
1109         /* If there is data waiting, eat it up */
1110         if (i->p && *i->p) {
1111                 ch = *i->p++;
1112         } else {
1113                 /* need to double check i->file because we might be doing something
1114                  * more complicated by now, like sourcing or substituting. */
1115 #ifndef __U_BOOT__
1116                 if (i->__promptme && interactive && i->file == stdin) {
1117                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1118 #else
1119                         while(! i->p  || strlen(i->p)==0 ) {
1120 #endif
1121                                 get_user_input(i);
1122                         }
1123                         i->promptmode=2;
1124 #ifndef __U_BOOT__
1125                         i->__promptme = 0;
1126 #endif
1127                         if (i->p && *i->p) {
1128                                 ch = *i->p++;
1129                         }
1130 #ifndef __U_BOOT__
1131                 } else {
1132                         ch = fgetc(i->file);
1133                 }
1134
1135 #endif
1136                 debug_printf("b_getch: got a %d\n", ch);
1137         }
1138 #ifndef __U_BOOT__
1139         if (ch == '\n') i->__promptme=1;
1140 #endif
1141         return ch;
1142 }
1143
1144 /* All the callers guarantee this routine will never be
1145  * used right after a newline, so prompting is not needed.
1146  */
1147 static int file_peek(struct in_str *i)
1148 {
1149 #ifndef __U_BOOT__
1150         if (i->p && *i->p) {
1151 #endif
1152                 return *i->p;
1153 #ifndef __U_BOOT__
1154         } else {
1155                 i->peek_buf[0] = fgetc(i->file);
1156                 i->peek_buf[1] = '\0';
1157                 i->p = i->peek_buf;
1158                 debug_printf("b_peek: got a %d\n", *i->p);
1159                 return *i->p;
1160         }
1161 #endif
1162 }
1163
1164 #ifndef __U_BOOT__
1165 static void setup_file_in_str(struct in_str *i, FILE *f)
1166 #else
1167 static void setup_file_in_str(struct in_str *i)
1168 #endif
1169 {
1170         i->peek = file_peek;
1171         i->get = file_get;
1172         i->__promptme=1;
1173         i->promptmode=1;
1174 #ifndef __U_BOOT__
1175         i->file = f;
1176 #endif
1177         i->p = NULL;
1178 }
1179
1180 static void setup_string_in_str(struct in_str *i, const char *s)
1181 {
1182         i->peek = static_peek;
1183         i->get = static_get;
1184         i->__promptme=1;
1185         i->promptmode=1;
1186         i->p = s;
1187 }
1188
1189 #ifndef __U_BOOT__
1190 static void mark_open(int fd)
1191 {
1192         struct close_me *new = xmalloc(sizeof(struct close_me));
1193         new->fd = fd;
1194         new->next = close_me_head;
1195         close_me_head = new;
1196 }
1197
1198 static void mark_closed(int fd)
1199 {
1200         struct close_me *tmp;
1201         if (close_me_head == NULL || close_me_head->fd != fd)
1202                 error_msg_and_die("corrupt close_me");
1203         tmp = close_me_head;
1204         close_me_head = close_me_head->next;
1205         free(tmp);
1206 }
1207
1208 static void close_all(void)
1209 {
1210         struct close_me *c;
1211         for (c=close_me_head; c; c=c->next) {
1212                 close(c->fd);
1213         }
1214         close_me_head = NULL;
1215 }
1216
1217 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1218  * and stderr if they are redirected. */
1219 static int setup_redirects(struct child_prog *prog, int squirrel[])
1220 {
1221         int openfd, mode;
1222         struct redir_struct *redir;
1223
1224         for (redir=prog->redirects; redir; redir=redir->next) {
1225                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1226                         /* something went wrong in the parse.  Pretend it didn't happen */
1227                         continue;
1228                 }
1229                 if (redir->dup == -1) {
1230                         mode=redir_table[redir->type].mode;
1231                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1232                         if (openfd < 0) {
1233                         /* this could get lost if stderr has been redirected, but
1234                            bash and ash both lose it as well (though zsh doesn't!) */
1235                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1236                                 return 1;
1237                         }
1238                 } else {
1239                         openfd = redir->dup;
1240                 }
1241
1242                 if (openfd != redir->fd) {
1243                         if (squirrel && redir->fd < 3) {
1244                                 squirrel[redir->fd] = dup(redir->fd);
1245                         }
1246                         if (openfd == -3) {
1247                                 close(openfd);
1248                         } else {
1249                                 dup2(openfd, redir->fd);
1250                                 if (redir->dup == -1)
1251                                         close (openfd);
1252                         }
1253                 }
1254         }
1255         return 0;
1256 }
1257
1258 static void restore_redirects(int squirrel[])
1259 {
1260         int i, fd;
1261         for (i=0; i<3; i++) {
1262                 fd = squirrel[i];
1263                 if (fd != -1) {
1264                         /* No error checking.  I sure wouldn't know what
1265                          * to do with an error if I found one! */
1266                         dup2(fd, i);
1267                         close(fd);
1268                 }
1269         }
1270 }
1271
1272 /* never returns */
1273 /* XXX no exit() here.  If you don't exec, use _exit instead.
1274  * The at_exit handlers apparently confuse the calling process,
1275  * in particular stdin handling.  Not sure why? */
1276 static void pseudo_exec(struct child_prog *child)
1277 {
1278         int i, rcode;
1279         char *p;
1280         struct built_in_command *x;
1281         if (child->argv) {
1282                 for (i=0; is_assignment(child->argv[i]); i++) {
1283                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1284                         p = insert_var_value(child->argv[i]);
1285                         putenv(strdup(p));
1286                         if (p != child->argv[i]) free(p);
1287                 }
1288                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1289                                         to exit, and therefore don't need to keep data
1290                                         structures consistent for free() use. */
1291                 /* If a variable is assigned in a forest, and nobody listens,
1292                  * was it ever really set?
1293                  */
1294                 if (child->argv[0] == NULL) {
1295                         _exit(EXIT_SUCCESS);
1296                 }
1297
1298                 /*
1299                  * Check if the command matches any of the builtins.
1300                  * Depending on context, this might be redundant.  But it's
1301                  * easier to waste a few CPU cycles than it is to figure out
1302                  * if this is one of those cases.
1303                  */
1304                 for (x = bltins; x->cmd; x++) {
1305                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1306                                 debug_printf("builtin exec %s\n", child->argv[0]);
1307                                 rcode = x->function(child);
1308                                 fflush(stdout);
1309                                 _exit(rcode);
1310                         }
1311                 }
1312
1313                 /* Check if the command matches any busybox internal commands
1314                  * ("applets") here.
1315                  * FIXME: This feature is not 100% safe, since
1316                  * BusyBox is not fully reentrant, so we have no guarantee the things
1317                  * from the .bss are still zeroed, or that things from .data are still
1318                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1319                  * really dislike relying on /proc for things.  We could exec ourself
1320                  * from global_argv[0], but if we are in a chroot, we may not be able
1321                  * to find ourself... */
1322 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1323                 {
1324                         int argc_l;
1325                         char** argv_l=child->argv;
1326                         char *name = child->argv[0];
1327
1328 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1329                         /* Following discussions from November 2000 on the busybox mailing
1330                          * list, the default configuration, (without
1331                          * get_last_path_component()) lets the user force use of an
1332                          * external command by specifying the full (with slashes) filename.
1333                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1334                          * _aways_ override external commands, so if you want to run
1335                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1336                          * filesystem and is _not_ busybox.  Some systems may want this,
1337                          * most do not.  */
1338                         name = get_last_path_component(name);
1339 #endif
1340                         /* Count argc for use in a second... */
1341                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1342                         optind = 1;
1343                         debug_printf("running applet %s\n", name);
1344                         run_applet_by_name(name, argc_l, child->argv);
1345                 }
1346 #endif
1347                 debug_printf("exec of %s\n",child->argv[0]);
1348                 execvp(child->argv[0],child->argv);
1349                 perror_msg("couldn't exec: %s",child->argv[0]);
1350                 _exit(1);
1351         } else if (child->group) {
1352                 debug_printf("runtime nesting to group\n");
1353                 interactive=0;    /* crucial!!!! */
1354                 rcode = run_list_real(child->group);
1355                 /* OK to leak memory by not calling free_pipe_list,
1356                  * since this process is about to exit */
1357                 _exit(rcode);
1358         } else {
1359                 /* Can happen.  See what bash does with ">foo" by itself. */
1360                 debug_printf("trying to pseudo_exec null command\n");
1361                 _exit(EXIT_SUCCESS);
1362         }
1363 }
1364
1365 static void insert_bg_job(struct pipe *pi)
1366 {
1367         struct pipe *thejob;
1368
1369         /* Linear search for the ID of the job to use */
1370         pi->jobid = 1;
1371         for (thejob = job_list; thejob; thejob = thejob->next)
1372                 if (thejob->jobid >= pi->jobid)
1373                         pi->jobid = thejob->jobid + 1;
1374
1375         /* add thejob to the list of running jobs */
1376         if (!job_list) {
1377                 thejob = job_list = xmalloc(sizeof(*thejob));
1378         } else {
1379                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1380                 thejob->next = xmalloc(sizeof(*thejob));
1381                 thejob = thejob->next;
1382         }
1383
1384         /* physically copy the struct job */
1385         memcpy(thejob, pi, sizeof(struct pipe));
1386         thejob->next = NULL;
1387         thejob->running_progs = thejob->num_progs;
1388         thejob->stopped_progs = 0;
1389         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1390
1391         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1392         {
1393                 char *bar=thejob->text;
1394                 char **foo=pi->progs[0].argv;
1395                 while(foo && *foo) {
1396                         bar += sprintf(bar, "%s ", *foo++);
1397                 }
1398         }
1399
1400         /* we don't wait for background thejobs to return -- append it
1401            to the list of backgrounded thejobs and leave it alone */
1402         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1403         last_bg_pid = thejob->progs[0].pid;
1404         last_jobid = thejob->jobid;
1405 }
1406
1407 /* remove a backgrounded job */
1408 static void remove_bg_job(struct pipe *pi)
1409 {
1410         struct pipe *prev_pipe;
1411
1412         if (pi == job_list) {
1413                 job_list = pi->next;
1414         } else {
1415                 prev_pipe = job_list;
1416                 while (prev_pipe->next != pi)
1417                         prev_pipe = prev_pipe->next;
1418                 prev_pipe->next = pi->next;
1419         }
1420         if (job_list)
1421                 last_jobid = job_list->jobid;
1422         else
1423                 last_jobid = 0;
1424
1425         pi->stopped_progs = 0;
1426         free_pipe(pi, 0);
1427         free(pi);
1428 }
1429
1430 /* Checks to see if any processes have exited -- if they
1431    have, figure out why and see if a job has completed */
1432 static int checkjobs(struct pipe* fg_pipe)
1433 {
1434         int attributes;
1435         int status;
1436         int prognum = 0;
1437         struct pipe *pi;
1438         pid_t childpid;
1439
1440         attributes = WUNTRACED;
1441         if (fg_pipe==NULL) {
1442                 attributes |= WNOHANG;
1443         }
1444
1445         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1446                 if (fg_pipe) {
1447                         int i, rcode = 0;
1448                         for (i=0; i < fg_pipe->num_progs; i++) {
1449                                 if (fg_pipe->progs[i].pid == childpid) {
1450                                         if (i==fg_pipe->num_progs-1)
1451                                                 rcode=WEXITSTATUS(status);
1452                                         (fg_pipe->num_progs)--;
1453                                         return(rcode);
1454                                 }
1455                         }
1456                 }
1457
1458                 for (pi = job_list; pi; pi = pi->next) {
1459                         prognum = 0;
1460                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1461                                 prognum++;
1462                         }
1463                         if (prognum < pi->num_progs)
1464                                 break;
1465                 }
1466
1467                 if(pi==NULL) {
1468                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1469                         continue;
1470                 }
1471
1472                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1473                         /* child exited */
1474                         pi->running_progs--;
1475                         pi->progs[prognum].pid = 0;
1476
1477                         if (!pi->running_progs) {
1478                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1479                                 remove_bg_job(pi);
1480                         }
1481                 } else {
1482                         /* child stopped */
1483                         pi->stopped_progs++;
1484                         pi->progs[prognum].is_stopped = 1;
1485
1486 #if 0
1487                         /* Printing this stuff is a pain, since it tends to
1488                          * overwrite the prompt an inconveinient moments.  So
1489                          * don't do that.  */
1490                         if (pi->stopped_progs == pi->num_progs) {
1491                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1492                         }
1493 #endif
1494                 }
1495         }
1496
1497         if (childpid == -1 && errno != ECHILD)
1498                 perror_msg("waitpid");
1499
1500         /* move the shell to the foreground */
1501         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1502         /*      perror_msg("tcsetpgrp-2"); */
1503         return -1;
1504 }
1505
1506 /* Figure out our controlling tty, checking in order stderr,
1507  * stdin, and stdout.  If check_pgrp is set, also check that
1508  * we belong to the foreground process group associated with
1509  * that tty.  The value of shell_terminal is needed in order to call
1510  * tcsetpgrp(shell_terminal, ...); */
1511 void controlling_tty(int check_pgrp)
1512 {
1513         pid_t curpgrp;
1514
1515         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1516                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1517                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1518                 goto shell_terminal_error;
1519
1520         if (check_pgrp && curpgrp != getpgid(0))
1521                 goto shell_terminal_error;
1522
1523         return;
1524
1525 shell_terminal_error:
1526                 shell_terminal = -1;
1527                 return;
1528 }
1529 #endif
1530
1531 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1532  * to finish.  See checkjobs().
1533  *
1534  * return code is normally -1, when the caller has to wait for children
1535  * to finish to determine the exit status of the pipe.  If the pipe
1536  * is a simple builtin command, however, the action is done by the
1537  * time run_pipe_real returns, and the exit code is provided as the
1538  * return value.
1539  *
1540  * The input of the pipe is always stdin, the output is always
1541  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1542  * because it tries to avoid running the command substitution in
1543  * subshell, when that is in fact necessary.  The subshell process
1544  * now has its stdout directed to the input of the appropriate pipe,
1545  * so this routine is noticeably simpler.
1546  */
1547 static int run_pipe_real(struct pipe *pi)
1548 {
1549         int i;
1550 #ifndef __U_BOOT__
1551         int nextin, nextout;
1552         int pipefds[2];                         /* pipefds[0] is for reading */
1553         struct child_prog *child;
1554         struct built_in_command *x;
1555         char *p;
1556 # if __GNUC__
1557         /* Avoid longjmp clobbering */
1558         (void) &i;
1559         (void) &nextin;
1560         (void) &nextout;
1561         (void) &child;
1562 # endif
1563 #else
1564         int nextin;
1565         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1566         struct child_prog *child;
1567         cmd_tbl_t *cmdtp;
1568         char *p;
1569 # if __GNUC__
1570         /* Avoid longjmp clobbering */
1571         (void) &i;
1572         (void) &nextin;
1573         (void) &child;
1574 # endif
1575 #endif  /* __U_BOOT__ */
1576
1577         nextin = 0;
1578 #ifndef __U_BOOT__
1579         pi->pgrp = -1;
1580 #endif
1581
1582         /* Check if this is a simple builtin (not part of a pipe).
1583          * Builtins within pipes have to fork anyway, and are handled in
1584          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1585          */
1586         if (pi->num_progs == 1) child = & (pi->progs[0]);
1587 #ifndef __U_BOOT__
1588         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1589                 int squirrel[] = {-1, -1, -1};
1590                 int rcode;
1591                 debug_printf("non-subshell grouping\n");
1592                 setup_redirects(child, squirrel);
1593                 /* XXX could we merge code with following builtin case,
1594                  * by creating a pseudo builtin that calls run_list_real? */
1595                 rcode = run_list_real(child->group);
1596                 restore_redirects(squirrel);
1597 #else
1598                 if (pi->num_progs == 1 && child->group) {
1599                 int rcode;
1600                 debug_printf("non-subshell grouping\n");
1601                 rcode = run_list_real(child->group);
1602 #endif
1603                 return rcode;
1604         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1605                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1606                 if (i!=0 && child->argv[i]==NULL) {
1607                         /* assignments, but no command: set the local environment */
1608                         for (i=0; child->argv[i]!=NULL; i++) {
1609
1610                                 /* Ok, this case is tricky.  We have to decide if this is a
1611                                  * local variable, or an already exported variable.  If it is
1612                                  * already exported, we have to export the new value.  If it is
1613                                  * not exported, we need only set this as a local variable.
1614                                  * This junk is all to decide whether or not to export this
1615                                  * variable. */
1616                                 int export_me=0;
1617                                 char *name, *value;
1618                                 name = xstrdup(child->argv[i]);
1619                                 debug_printf("Local environment set: %s\n", name);
1620                                 value = strchr(name, '=');
1621                                 if (value)
1622                                         *value=0;
1623 #ifndef __U_BOOT__
1624                                 if ( get_local_var(name)) {
1625                                         export_me=1;
1626                                 }
1627 #endif
1628                                 free(name);
1629                                 p = insert_var_value(child->argv[i]);
1630                                 set_local_var(p, export_me);
1631                                 if (p != child->argv[i]) free(p);
1632                         }
1633                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1634                 }
1635                 for (i = 0; is_assignment(child->argv[i]); i++) {
1636                         p = insert_var_value(child->argv[i]);
1637 #ifndef __U_BOOT__
1638                         putenv(strdup(p));
1639 #else
1640                         set_local_var(p, 0);
1641 #endif
1642                         if (p != child->argv[i]) {
1643                                 child->sp--;
1644                                 free(p);
1645                         }
1646                 }
1647                 if (child->sp) {
1648                         char * str = NULL;
1649
1650                         str = make_string((child->argv + i));
1651                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1652                         free(str);
1653                         return last_return_code;
1654                 }
1655 #ifndef __U_BOOT__
1656                 for (x = bltins; x->cmd; x++) {
1657                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1658                                 int squirrel[] = {-1, -1, -1};
1659                                 int rcode;
1660                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1661                                         debug_printf("magic exec\n");
1662                                         setup_redirects(child,NULL);
1663                                         return EXIT_SUCCESS;
1664                                 }
1665                                 debug_printf("builtin inline %s\n", child->argv[0]);
1666                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1667                                  * This is perfect for work that comes after exec().
1668                                  * Is it really safe for inline use?  Experimentally,
1669                                  * things seem to work with glibc. */
1670                                 setup_redirects(child, squirrel);
1671 #else
1672                         /* check ";", because ,example , argv consist from
1673                          * "help;flinfo" must not execute
1674                          */
1675                         if (strchr(child->argv[i], ';')) {
1676                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1677                                         child->argv[i]);
1678                                 return -1;
1679                         }
1680                         /* Look up command in command table */
1681
1682
1683                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1684                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1685                                 return -1;      /* give up after bad command */
1686                         } else {
1687                                 int rcode;
1688 #if defined(CONFIG_CMD_BOOTD)
1689             extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1690
1691                                 /* avoid "bootd" recursion */
1692                                 if (cmdtp->cmd == do_bootd) {
1693                                         if (flag & CMD_FLAG_BOOTD) {
1694                                                 printf ("'bootd' recursion detected\n");
1695                                                 return -1;
1696                                         }
1697                                 else
1698                                         flag |= CMD_FLAG_BOOTD;
1699                                 }
1700 #endif
1701                                 /* found - check max args */
1702                                 if ((child->argc - i) > cmdtp->maxargs) {
1703                                         printf ("Usage:\n%s\n", cmdtp->usage);
1704                                         return -1;
1705                                 }
1706 #endif
1707                                 child->argv+=i;  /* XXX horrible hack */
1708 #ifndef __U_BOOT__
1709                                 rcode = x->function(child);
1710 #else
1711                                 /* OK - call function to do the command */
1712
1713                                 rcode = (cmdtp->cmd)
1714 (cmdtp, flag,child->argc-i,&child->argv[i]);
1715                                 if ( !cmdtp->repeatable )
1716                                         flag_repeat = 0;
1717
1718
1719 #endif
1720                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1721 #ifndef __U_BOOT__
1722
1723                                 restore_redirects(squirrel);
1724 #endif
1725
1726                                 return rcode;
1727                         }
1728                 }
1729 #ifndef __U_BOOT__
1730         }
1731
1732         for (i = 0; i < pi->num_progs; i++) {
1733                 child = & (pi->progs[i]);
1734
1735                 /* pipes are inserted between pairs of commands */
1736                 if ((i + 1) < pi->num_progs) {
1737                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1738                         nextout = pipefds[1];
1739                 } else {
1740                         nextout=1;
1741                         pipefds[0] = -1;
1742                 }
1743
1744                 /* XXX test for failed fork()? */
1745                 if (!(child->pid = fork())) {
1746                         /* Set the handling for job control signals back to the default.  */
1747                         signal(SIGINT, SIG_DFL);
1748                         signal(SIGQUIT, SIG_DFL);
1749                         signal(SIGTERM, SIG_DFL);
1750                         signal(SIGTSTP, SIG_DFL);
1751                         signal(SIGTTIN, SIG_DFL);
1752                         signal(SIGTTOU, SIG_DFL);
1753                         signal(SIGCHLD, SIG_DFL);
1754
1755                         close_all();
1756
1757                         if (nextin != 0) {
1758                                 dup2(nextin, 0);
1759                                 close(nextin);
1760                         }
1761                         if (nextout != 1) {
1762                                 dup2(nextout, 1);
1763                                 close(nextout);
1764                         }
1765                         if (pipefds[0]!=-1) {
1766                                 close(pipefds[0]);  /* opposite end of our output pipe */
1767                         }
1768
1769                         /* Like bash, explicit redirects override pipes,
1770                          * and the pipe fd is available for dup'ing. */
1771                         setup_redirects(child,NULL);
1772
1773                         if (interactive && pi->followup!=PIPE_BG) {
1774                                 /* If we (the child) win the race, put ourselves in the process
1775                                  * group whose leader is the first process in this pipe. */
1776                                 if (pi->pgrp < 0) {
1777                                         pi->pgrp = getpid();
1778                                 }
1779                                 if (setpgid(0, pi->pgrp) == 0) {
1780                                         tcsetpgrp(2, pi->pgrp);
1781                                 }
1782                         }
1783
1784                         pseudo_exec(child);
1785                 }
1786
1787
1788                 /* put our child in the process group whose leader is the
1789                    first process in this pipe */
1790                 if (pi->pgrp < 0) {
1791                         pi->pgrp = child->pid;
1792                 }
1793                 /* Don't check for errors.  The child may be dead already,
1794                  * in which case setpgid returns error code EACCES. */
1795                 setpgid(child->pid, pi->pgrp);
1796
1797                 if (nextin != 0)
1798                         close(nextin);
1799                 if (nextout != 1)
1800                         close(nextout);
1801
1802                 /* If there isn't another process, nextin is garbage
1803                    but it doesn't matter */
1804                 nextin = pipefds[0];
1805         }
1806 #endif
1807         return -1;
1808 }
1809
1810 static int run_list_real(struct pipe *pi)
1811 {
1812         char *save_name = NULL;
1813         char **list = NULL;
1814         char **save_list = NULL;
1815         struct pipe *rpipe;
1816         int flag_rep = 0;
1817 #ifndef __U_BOOT__
1818         int save_num_progs;
1819 #endif
1820         int rcode=0, flag_skip=1;
1821         int flag_restore = 0;
1822         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1823         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1824         /* check syntax for "for" */
1825         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1826                 if ((rpipe->r_mode == RES_IN ||
1827                     rpipe->r_mode == RES_FOR) &&
1828                     (rpipe->next == NULL)) {
1829                                 syntax();
1830 #ifdef __U_BOOT__
1831                                 flag_repeat = 0;
1832 #endif
1833                                 return 1;
1834                 }
1835                 if ((rpipe->r_mode == RES_IN &&
1836                         (rpipe->next->r_mode == RES_IN &&
1837                         rpipe->next->progs->argv != NULL))||
1838                         (rpipe->r_mode == RES_FOR &&
1839                         rpipe->next->r_mode != RES_IN)) {
1840                                 syntax();
1841 #ifdef __U_BOOT__
1842                                 flag_repeat = 0;
1843 #endif
1844                                 return 1;
1845                 }
1846         }
1847         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1848                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1849                         pi->r_mode == RES_FOR) {
1850 #ifdef __U_BOOT__
1851                                 /* check Ctrl-C */
1852                                 ctrlc();
1853                                 if ((had_ctrlc())) {
1854                                         return 1;
1855                                 }
1856 #endif
1857                                 flag_restore = 0;
1858                                 if (!rpipe) {
1859                                         flag_rep = 0;
1860                                         rpipe = pi;
1861                                 }
1862                 }
1863                 rmode = pi->r_mode;
1864                 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);
1865                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1866                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1867                         continue;
1868                 }
1869                 flag_skip = 1;
1870                 skip_more_in_this_rmode = RES_XXXX;
1871                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1872                 if (rmode == RES_THEN &&  if_code) continue;
1873                 if (rmode == RES_ELSE && !if_code) continue;
1874                 if (rmode == RES_ELIF && !if_code) break;
1875                 if (rmode == RES_FOR && pi->num_progs) {
1876                         if (!list) {
1877                                 /* if no variable values after "in" we skip "for" */
1878                                 if (!pi->next->progs->argv) continue;
1879                                 /* create list of variable values */
1880                                 list = make_list_in(pi->next->progs->argv,
1881                                         pi->progs->argv[0]);
1882                                 save_list = list;
1883                                 save_name = pi->progs->argv[0];
1884                                 pi->progs->argv[0] = NULL;
1885                                 flag_rep = 1;
1886                         }
1887                         if (!(*list)) {
1888                                 free(pi->progs->argv[0]);
1889                                 free(save_list);
1890                                 list = NULL;
1891                                 flag_rep = 0;
1892                                 pi->progs->argv[0] = save_name;
1893 #ifndef __U_BOOT__
1894                                 pi->progs->glob_result.gl_pathv[0] =
1895                                         pi->progs->argv[0];
1896 #endif
1897                                 continue;
1898                         } else {
1899                                 /* insert new value from list for variable */
1900                                 if (pi->progs->argv[0])
1901                                         free(pi->progs->argv[0]);
1902                                 pi->progs->argv[0] = *list++;
1903 #ifndef __U_BOOT__
1904                                 pi->progs->glob_result.gl_pathv[0] =
1905                                         pi->progs->argv[0];
1906 #endif
1907                         }
1908                 }
1909                 if (rmode == RES_IN) continue;
1910                 if (rmode == RES_DO) {
1911                         if (!flag_rep) continue;
1912                 }
1913                 if ((rmode == RES_DONE)) {
1914                         if (flag_rep) {
1915                                 flag_restore = 1;
1916                         } else {
1917                                 rpipe = NULL;
1918                         }
1919                 }
1920                 if (pi->num_progs == 0) continue;
1921 #ifndef __U_BOOT__
1922                 save_num_progs = pi->num_progs; /* save number of programs */
1923 #endif
1924                 rcode = run_pipe_real(pi);
1925                 debug_printf("run_pipe_real returned %d\n",rcode);
1926 #ifndef __U_BOOT__
1927                 if (rcode!=-1) {
1928                         /* We only ran a builtin: rcode was set by the return value
1929                          * of run_pipe_real(), and we don't need to wait for anything. */
1930                 } else if (pi->followup==PIPE_BG) {
1931                         /* XXX check bash's behavior with nontrivial pipes */
1932                         /* XXX compute jobid */
1933                         /* XXX what does bash do with attempts to background builtins? */
1934                         insert_bg_job(pi);
1935                         rcode = EXIT_SUCCESS;
1936                 } else {
1937                         if (interactive) {
1938                                 /* move the new process group into the foreground */
1939                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1940                                         perror_msg("tcsetpgrp-3");
1941                                 rcode = checkjobs(pi);
1942                                 /* move the shell to the foreground */
1943                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1944                                         perror_msg("tcsetpgrp-4");
1945                         } else {
1946                                 rcode = checkjobs(pi);
1947                         }
1948                         debug_printf("checkjobs returned %d\n",rcode);
1949                 }
1950                 last_return_code=rcode;
1951 #else
1952                 if (rcode < -1) {
1953                         last_return_code = -rcode - 2;
1954                         return -2;      /* exit */
1955                 }
1956                 last_return_code=(rcode == 0) ? 0 : 1;
1957 #endif
1958 #ifndef __U_BOOT__
1959                 pi->num_progs = save_num_progs; /* restore number of programs */
1960 #endif
1961                 if ( rmode == RES_IF || rmode == RES_ELIF )
1962                         next_if_code=rcode;  /* can be overwritten a number of times */
1963                 if (rmode == RES_WHILE)
1964                         flag_rep = !last_return_code;
1965                 if (rmode == RES_UNTIL)
1966                         flag_rep = last_return_code;
1967                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1968                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1969                         skip_more_in_this_rmode=rmode;
1970 #ifndef __U_BOOT__
1971                 checkjobs(NULL);
1972 #endif
1973         }
1974         return rcode;
1975 }
1976
1977 /* broken, of course, but OK for testing */
1978 static char *indenter(int i)
1979 {
1980         static char blanks[]="                                    ";
1981         return &blanks[sizeof(blanks)-i-1];
1982 }
1983
1984 /* return code is the exit status of the pipe */
1985 static int free_pipe(struct pipe *pi, int indent)
1986 {
1987         char **p;
1988         struct child_prog *child;
1989 #ifndef __U_BOOT__
1990         struct redir_struct *r, *rnext;
1991 #endif
1992         int a, i, ret_code=0;
1993         char *ind = indenter(indent);
1994
1995 #ifndef __U_BOOT__
1996         if (pi->stopped_progs > 0)
1997                 return ret_code;
1998         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1999 #endif
2000         for (i=0; i<pi->num_progs; i++) {
2001                 child = &pi->progs[i];
2002                 final_printf("%s  command %d:\n",ind,i);
2003                 if (child->argv) {
2004                         for (a=0,p=child->argv; *p; a++,p++) {
2005                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
2006                         }
2007 #ifndef __U_BOOT__
2008                         globfree(&child->glob_result);
2009 #else
2010                         for (a = child->argc;a >= 0;a--) {
2011                                 free(child->argv[a]);
2012                         }
2013                                         free(child->argv);
2014                         child->argc = 0;
2015 #endif
2016                         child->argv=NULL;
2017                 } else if (child->group) {
2018 #ifndef __U_BOOT__
2019                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
2020 #endif
2021                         ret_code = free_pipe_list(child->group,indent+3);
2022                         final_printf("%s   end group\n",ind);
2023                 } else {
2024                         final_printf("%s   (nil)\n",ind);
2025                 }
2026 #ifndef __U_BOOT__
2027                 for (r=child->redirects; r; r=rnext) {
2028                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2029                         if (r->dup == -1) {
2030                                 /* guard against the case >$FOO, where foo is unset or blank */
2031                                 if (r->word.gl_pathv) {
2032                                         final_printf(" %s\n", *r->word.gl_pathv);
2033                                         globfree(&r->word);
2034                                 }
2035                         } else {
2036                                 final_printf("&%d\n", r->dup);
2037                         }
2038                         rnext=r->next;
2039                         free(r);
2040                 }
2041                 child->redirects=NULL;
2042 #endif
2043         }
2044         free(pi->progs);   /* children are an array, they get freed all at once */
2045         pi->progs=NULL;
2046         return ret_code;
2047 }
2048
2049 static int free_pipe_list(struct pipe *head, int indent)
2050 {
2051         int rcode=0;   /* if list has no members */
2052         struct pipe *pi, *next;
2053         char *ind = indenter(indent);
2054         for (pi=head; pi; pi=next) {
2055                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2056                 rcode = free_pipe(pi, indent);
2057                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2058                 next=pi->next;
2059                 pi->next=NULL;
2060                 free(pi);
2061         }
2062         return rcode;
2063 }
2064
2065 /* Select which version we will use */
2066 static int run_list(struct pipe *pi)
2067 {
2068         int rcode=0;
2069 #ifndef __U_BOOT__
2070         if (fake_mode==0) {
2071 #endif
2072                 rcode = run_list_real(pi);
2073 #ifndef __U_BOOT__
2074         }
2075 #endif
2076         /* free_pipe_list has the side effect of clearing memory
2077          * In the long run that function can be merged with run_list_real,
2078          * but doing that now would hobble the debugging effort. */
2079         free_pipe_list(pi,0);
2080         return rcode;
2081 }
2082
2083 /* The API for glob is arguably broken.  This routine pushes a non-matching
2084  * string into the output structure, removing non-backslashed backslashes.
2085  * If someone can prove me wrong, by performing this function within the
2086  * original glob(3) api, feel free to rewrite this routine into oblivion.
2087  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2088  * XXX broken if the last character is '\\', check that before calling.
2089  */
2090 #ifndef __U_BOOT__
2091 static int globhack(const char *src, int flags, glob_t *pglob)
2092 {
2093         int cnt=0, pathc;
2094         const char *s;
2095         char *dest;
2096         for (cnt=1, s=src; s && *s; s++) {
2097                 if (*s == '\\') s++;
2098                 cnt++;
2099         }
2100         dest = malloc(cnt);
2101         if (!dest) return GLOB_NOSPACE;
2102         if (!(flags & GLOB_APPEND)) {
2103                 pglob->gl_pathv=NULL;
2104                 pglob->gl_pathc=0;
2105                 pglob->gl_offs=0;
2106                 pglob->gl_offs=0;
2107         }
2108         pathc = ++pglob->gl_pathc;
2109         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2110         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2111         pglob->gl_pathv[pathc-1]=dest;
2112         pglob->gl_pathv[pathc]=NULL;
2113         for (s=src; s && *s; s++, dest++) {
2114                 if (*s == '\\') s++;
2115                 *dest = *s;
2116         }
2117         *dest='\0';
2118         return 0;
2119 }
2120
2121 /* XXX broken if the last character is '\\', check that before calling */
2122 static int glob_needed(const char *s)
2123 {
2124         for (; *s; s++) {
2125                 if (*s == '\\') s++;
2126                 if (strchr("*[?",*s)) return 1;
2127         }
2128         return 0;
2129 }
2130
2131 #if 0
2132 static void globprint(glob_t *pglob)
2133 {
2134         int i;
2135         debug_printf("glob_t at %p:\n", pglob);
2136         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2137                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2138         for (i=0; i<pglob->gl_pathc; i++)
2139                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2140                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2141 }
2142 #endif
2143
2144 static int xglob(o_string *dest, int flags, glob_t *pglob)
2145 {
2146         int gr;
2147
2148         /* short-circuit for null word */
2149         /* we can code this better when the debug_printf's are gone */
2150         if (dest->length == 0) {
2151                 if (dest->nonnull) {
2152                         /* bash man page calls this an "explicit" null */
2153                         gr = globhack(dest->data, flags, pglob);
2154                         debug_printf("globhack returned %d\n",gr);
2155                 } else {
2156                         return 0;
2157                 }
2158         } else if (glob_needed(dest->data)) {
2159                 gr = glob(dest->data, flags, NULL, pglob);
2160                 debug_printf("glob returned %d\n",gr);
2161                 if (gr == GLOB_NOMATCH) {
2162                         /* quote removal, or more accurately, backslash removal */
2163                         gr = globhack(dest->data, flags, pglob);
2164                         debug_printf("globhack returned %d\n",gr);
2165                 }
2166         } else {
2167                 gr = globhack(dest->data, flags, pglob);
2168                 debug_printf("globhack returned %d\n",gr);
2169         }
2170         if (gr == GLOB_NOSPACE)
2171                 error_msg_and_die("out of memory during glob");
2172         if (gr != 0) { /* GLOB_ABORTED ? */
2173                 error_msg("glob(3) error %d",gr);
2174         }
2175         /* globprint(glob_target); */
2176         return gr;
2177 }
2178 #endif
2179
2180 #ifdef __U_BOOT__
2181 static char *get_dollar_var(char ch);
2182 #endif
2183
2184 /* This is used to get/check local shell variables */
2185 static char *get_local_var(const char *s)
2186 {
2187         struct variables *cur;
2188
2189         if (!s)
2190                 return NULL;
2191
2192 #ifdef __U_BOOT__
2193         if (*s == '$')
2194                 return get_dollar_var(s[1]);
2195 #endif
2196
2197         for (cur = top_vars; cur; cur=cur->next)
2198                 if(strcmp(cur->name, s)==0)
2199                         return cur->value;
2200         return NULL;
2201 }
2202
2203 /* This is used to set local shell variables
2204    flg_export==0 if only local (not exporting) variable
2205    flg_export==1 if "new" exporting environ
2206    flg_export>1  if current startup environ (not call putenv()) */
2207 static int set_local_var(const char *s, int flg_export)
2208 {
2209         char *name, *value;
2210         int result=0;
2211         struct variables *cur;
2212
2213 #ifdef __U_BOOT__
2214         /* might be possible! */
2215         if (!isalpha(*s))
2216                 return -1;
2217 #endif
2218
2219         name=strdup(s);
2220
2221 #ifdef __U_BOOT__
2222         if (getenv(name) != NULL) {
2223                 printf ("ERROR: "
2224                                 "There is a global environment variable with the same name.\n");
2225                 free(name);
2226                 return -1;
2227         }
2228 #endif
2229         /* Assume when we enter this function that we are already in
2230          * NAME=VALUE format.  So the first order of business is to
2231          * split 's' on the '=' into 'name' and 'value' */
2232         value = strchr(name, '=');
2233         if (value==0 && ++value==0) {
2234                 free(name);
2235                 return -1;
2236         }
2237         *value++ = 0;
2238
2239         for(cur = top_vars; cur; cur = cur->next) {
2240                 if(strcmp(cur->name, name)==0)
2241                         break;
2242         }
2243
2244         if(cur) {
2245                 if(strcmp(cur->value, value)==0) {
2246                         if(flg_export>0 && cur->flg_export==0)
2247                                 cur->flg_export=flg_export;
2248                         else
2249                                 result++;
2250                 } else {
2251                         if(cur->flg_read_only) {
2252                                 error_msg("%s: readonly variable", name);
2253                                 result = -1;
2254                         } else {
2255                                 if(flg_export>0 || cur->flg_export>1)
2256                                         cur->flg_export=1;
2257                                 free(cur->value);
2258
2259                                 cur->value = strdup(value);
2260                         }
2261                 }
2262         } else {
2263                 cur = malloc(sizeof(struct variables));
2264                 if(!cur) {
2265                         result = -1;
2266                 } else {
2267                         cur->name = strdup(name);
2268                         if(cur->name == 0) {
2269                                 free(cur);
2270                                 result = -1;
2271                         } else {
2272                                 struct variables *bottom = top_vars;
2273                                 cur->value = strdup(value);
2274                                 cur->next = 0;
2275                                 cur->flg_export = flg_export;
2276                                 cur->flg_read_only = 0;
2277                                 while(bottom->next) bottom=bottom->next;
2278                                 bottom->next = cur;
2279                         }
2280                 }
2281         }
2282
2283 #ifndef __U_BOOT__
2284         if(result==0 && cur->flg_export==1) {
2285                 *(value-1) = '=';
2286                 result = putenv(name);
2287         } else {
2288 #endif
2289                 free(name);
2290 #ifndef __U_BOOT__
2291                 if(result>0)            /* equivalent to previous set */
2292                         result = 0;
2293         }
2294 #endif
2295         return result;
2296 }
2297
2298 #ifndef __U_BOOT__
2299 static void unset_local_var(const char *name)
2300 {
2301         struct variables *cur;
2302
2303         if (name) {
2304                 for (cur = top_vars; cur; cur=cur->next) {
2305                         if(strcmp(cur->name, name)==0)
2306                                 break;
2307                 }
2308                 if(cur!=0) {
2309                         struct variables *next = top_vars;
2310                         if(cur->flg_read_only) {
2311                                 error_msg("%s: readonly variable", name);
2312                                 return;
2313                         } else {
2314                                 if(cur->flg_export)
2315                                         unsetenv(cur->name);
2316                                 free(cur->name);
2317                                 free(cur->value);
2318                                 while (next->next != cur)
2319                                         next = next->next;
2320                                 next->next = cur->next;
2321                         }
2322                         free(cur);
2323                 }
2324         }
2325 }
2326 #endif
2327
2328 static int is_assignment(const char *s)
2329 {
2330         if (s == NULL)
2331                 return 0;
2332
2333         if (!isalpha(*s)) return 0;
2334         ++s;
2335         while(isalnum(*s) || *s=='_') ++s;
2336         return *s=='=';
2337 }
2338
2339 #ifndef __U_BOOT__
2340 /* the src parameter allows us to peek forward to a possible &n syntax
2341  * for file descriptor duplication, e.g., "2>&1".
2342  * Return code is 0 normally, 1 if a syntax error is detected in src.
2343  * Resource errors (in xmalloc) cause the process to exit */
2344 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2345         struct in_str *input)
2346 {
2347         struct child_prog *child=ctx->child;
2348         struct redir_struct *redir = child->redirects;
2349         struct redir_struct *last_redir=NULL;
2350
2351         /* Create a new redir_struct and drop it onto the end of the linked list */
2352         while(redir) {
2353                 last_redir=redir;
2354                 redir=redir->next;
2355         }
2356         redir = xmalloc(sizeof(struct redir_struct));
2357         redir->next=NULL;
2358         redir->word.gl_pathv=NULL;
2359         if (last_redir) {
2360                 last_redir->next=redir;
2361         } else {
2362                 child->redirects=redir;
2363         }
2364
2365         redir->type=style;
2366         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2367
2368         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2369
2370         /* Check for a '2>&1' type redirect */
2371         redir->dup = redirect_dup_num(input);
2372         if (redir->dup == -2) return 1;  /* syntax error */
2373         if (redir->dup != -1) {
2374                 /* Erik had a check here that the file descriptor in question
2375                  * is legit; I postpone that to "run time"
2376                  * A "-" representation of "close me" shows up as a -3 here */
2377                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2378         } else {
2379                 /* We do _not_ try to open the file that src points to,
2380                  * since we need to return and let src be expanded first.
2381                  * Set ctx->pending_redirect, so we know what to do at the
2382                  * end of the next parsed word.
2383                  */
2384                 ctx->pending_redirect = redir;
2385         }
2386         return 0;
2387 }
2388 #endif
2389
2390 struct pipe *new_pipe(void) {
2391         struct pipe *pi;
2392         pi = xmalloc(sizeof(struct pipe));
2393         pi->num_progs = 0;
2394         pi->progs = NULL;
2395         pi->next = NULL;
2396         pi->followup = 0;  /* invalid */
2397         pi->r_mode = RES_NONE;
2398         return pi;
2399 }
2400
2401 static void initialize_context(struct p_context *ctx)
2402 {
2403         ctx->pipe=NULL;
2404 #ifndef __U_BOOT__
2405         ctx->pending_redirect=NULL;
2406 #endif
2407         ctx->child=NULL;
2408         ctx->list_head=new_pipe();
2409         ctx->pipe=ctx->list_head;
2410         ctx->w=RES_NONE;
2411         ctx->stack=NULL;
2412 #ifdef __U_BOOT__
2413         ctx->old_flag=0;
2414 #endif
2415         done_command(ctx);   /* creates the memory for working child */
2416 }
2417
2418 /* normal return is 0
2419  * if a reserved word is found, and processed, return 1
2420  * should handle if, then, elif, else, fi, for, while, until, do, done.
2421  * case, function, and select are obnoxious, save those for later.
2422  */
2423 struct reserved_combo {
2424         char *literal;
2425         int code;
2426         long flag;
2427 };
2428 /* Mostly a list of accepted follow-up reserved words.
2429  * FLAG_END means we are done with the sequence, and are ready
2430  * to turn the compound list into a command.
2431  * FLAG_START means the word must start a new compound list.
2432  */
2433 static struct reserved_combo reserved_list[] = {
2434         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2435         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2436         { "elif",  RES_ELIF,  FLAG_THEN },
2437         { "else",  RES_ELSE,  FLAG_FI   },
2438         { "fi",    RES_FI,    FLAG_END  },
2439         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2440         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2441         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2442         { "in",    RES_IN,    FLAG_DO   },
2443         { "do",    RES_DO,    FLAG_DONE },
2444         { "done",  RES_DONE,  FLAG_END  }
2445 };
2446 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2447
2448 int reserved_word(o_string *dest, struct p_context *ctx)
2449 {
2450         struct reserved_combo *r;
2451         for (r=reserved_list;
2452                 r<reserved_list+NRES; r++) {
2453                 if (strcmp(dest->data, r->literal) == 0) {
2454                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2455                         if (r->flag & FLAG_START) {
2456                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2457                                 debug_printf("push stack\n");
2458                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2459                                         syntax();
2460                                         free(new);
2461                                         ctx->w = RES_SNTX;
2462                                         b_reset(dest);
2463                                         return 1;
2464                                 }
2465                                 *new = *ctx;   /* physical copy */
2466                                 initialize_context(ctx);
2467                                 ctx->stack=new;
2468                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2469                                 syntax();
2470                                 ctx->w = RES_SNTX;
2471                                 b_reset(dest);
2472                                 return 1;
2473                         }
2474                         ctx->w=r->code;
2475                         ctx->old_flag = r->flag;
2476                         if (ctx->old_flag & FLAG_END) {
2477                                 struct p_context *old;
2478                                 debug_printf("pop stack\n");
2479                                 done_pipe(ctx,PIPE_SEQ);
2480                                 old = ctx->stack;
2481                                 old->child->group = ctx->list_head;
2482 #ifndef __U_BOOT__
2483                                 old->child->subshell = 0;
2484 #endif
2485                                 *ctx = *old;   /* physical copy */
2486                                 free(old);
2487                         }
2488                         b_reset (dest);
2489                         return 1;
2490                 }
2491         }
2492         return 0;
2493 }
2494
2495 /* normal return is 0.
2496  * Syntax or xglob errors return 1. */
2497 static int done_word(o_string *dest, struct p_context *ctx)
2498 {
2499         struct child_prog *child=ctx->child;
2500 #ifndef __U_BOOT__
2501         glob_t *glob_target;
2502         int gr, flags = 0;
2503 #else
2504         char *str, *s;
2505         int argc, cnt;
2506 #endif
2507
2508         debug_printf("done_word: %s %p\n", dest->data, child);
2509         if (dest->length == 0 && !dest->nonnull) {
2510                 debug_printf("  true null, ignored\n");
2511                 return 0;
2512         }
2513 #ifndef __U_BOOT__
2514         if (ctx->pending_redirect) {
2515                 glob_target = &ctx->pending_redirect->word;
2516         } else {
2517 #endif
2518                 if (child->group) {
2519                         syntax();
2520                         return 1;  /* syntax error, groups and arglists don't mix */
2521                 }
2522                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2523                         debug_printf("checking %s for reserved-ness\n",dest->data);
2524                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2525                 }
2526 #ifndef __U_BOOT__
2527                 glob_target = &child->glob_result;
2528                 if (child->argv) flags |= GLOB_APPEND;
2529 #else
2530                 for (cnt = 1, s = dest->data; s && *s; s++) {
2531                         if (*s == '\\') s++;
2532                         cnt++;
2533                 }
2534                 str = malloc(cnt);
2535                 if (!str) return 1;
2536                 if ( child->argv == NULL) {
2537                         child->argc=0;
2538                 }
2539                 argc = ++child->argc;
2540                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2541                 if (child->argv == NULL) return 1;
2542                 child->argv[argc-1]=str;
2543                 child->argv[argc]=NULL;
2544                 for (s = dest->data; s && *s; s++,str++) {
2545                         if (*s == '\\') s++;
2546                         *str = *s;
2547                 }
2548                 *str = '\0';
2549 #endif
2550 #ifndef __U_BOOT__
2551         }
2552         gr = xglob(dest, flags, glob_target);
2553         if (gr != 0) return 1;
2554 #endif
2555
2556         b_reset(dest);
2557 #ifndef __U_BOOT__
2558         if (ctx->pending_redirect) {
2559                 ctx->pending_redirect=NULL;
2560                 if (glob_target->gl_pathc != 1) {
2561                         error_msg("ambiguous redirect");
2562                         return 1;
2563                 }
2564         } else {
2565                 child->argv = glob_target->gl_pathv;
2566         }
2567 #endif
2568         if (ctx->w == RES_FOR) {
2569                 done_word(dest,ctx);
2570                 done_pipe(ctx,PIPE_SEQ);
2571         }
2572         return 0;
2573 }
2574
2575 /* The only possible error here is out of memory, in which case
2576  * xmalloc exits. */
2577 static int done_command(struct p_context *ctx)
2578 {
2579         /* The child is really already in the pipe structure, so
2580          * advance the pipe counter and make a new, null child.
2581          * Only real trickiness here is that the uncommitted
2582          * child structure, to which ctx->child points, is not
2583          * counted in pi->num_progs. */
2584         struct pipe *pi=ctx->pipe;
2585         struct child_prog *prog=ctx->child;
2586
2587         if (prog && prog->group == NULL
2588                  && prog->argv == NULL
2589 #ifndef __U_BOOT__
2590                  && prog->redirects == NULL) {
2591 #else
2592                                                                                 ) {
2593 #endif
2594                 debug_printf("done_command: skipping null command\n");
2595                 return 0;
2596         } else if (prog) {
2597                 pi->num_progs++;
2598                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2599         } else {
2600                 debug_printf("done_command: initializing\n");
2601         }
2602         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2603
2604         prog = pi->progs + pi->num_progs;
2605 #ifndef __U_BOOT__
2606         prog->redirects = NULL;
2607 #endif
2608         prog->argv = NULL;
2609 #ifndef __U_BOOT__
2610         prog->is_stopped = 0;
2611 #endif
2612         prog->group = NULL;
2613 #ifndef __U_BOOT__
2614         prog->glob_result.gl_pathv = NULL;
2615         prog->family = pi;
2616 #endif
2617         prog->sp = 0;
2618         ctx->child = prog;
2619         prog->type = ctx->type;
2620
2621         /* but ctx->pipe and ctx->list_head remain unchanged */
2622         return 0;
2623 }
2624
2625 static int done_pipe(struct p_context *ctx, pipe_style type)
2626 {
2627         struct pipe *new_p;
2628         done_command(ctx);  /* implicit closure of previous command */
2629         debug_printf("done_pipe, type %d\n", type);
2630         ctx->pipe->followup = type;
2631         ctx->pipe->r_mode = ctx->w;
2632         new_p=new_pipe();
2633         ctx->pipe->next = new_p;
2634         ctx->pipe = new_p;
2635         ctx->child = NULL;
2636         done_command(ctx);  /* set up new pipe to accept commands */
2637         return 0;
2638 }
2639
2640 #ifndef __U_BOOT__
2641 /* peek ahead in the in_str to find out if we have a "&n" construct,
2642  * as in "2>&1", that represents duplicating a file descriptor.
2643  * returns either -2 (syntax error), -1 (no &), or the number found.
2644  */
2645 static int redirect_dup_num(struct in_str *input)
2646 {
2647         int ch, d=0, ok=0;
2648         ch = b_peek(input);
2649         if (ch != '&') return -1;
2650
2651         b_getch(input);  /* get the & */
2652         ch=b_peek(input);
2653         if (ch == '-') {
2654                 b_getch(input);
2655                 return -3;  /* "-" represents "close me" */
2656         }
2657         while (isdigit(ch)) {
2658                 d = d*10+(ch-'0');
2659                 ok=1;
2660                 b_getch(input);
2661                 ch = b_peek(input);
2662         }
2663         if (ok) return d;
2664
2665         error_msg("ambiguous redirect");
2666         return -2;
2667 }
2668
2669 /* If a redirect is immediately preceded by a number, that number is
2670  * supposed to tell which file descriptor to redirect.  This routine
2671  * looks for such preceding numbers.  In an ideal world this routine
2672  * needs to handle all the following classes of redirects...
2673  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2674  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2675  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2676  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2677  * A -1 output from this program means no valid number was found, so the
2678  * caller should use the appropriate default for this redirection.
2679  */
2680 static int redirect_opt_num(o_string *o)
2681 {
2682         int num;
2683
2684         if (o->length==0) return -1;
2685         for(num=0; num<o->length; num++) {
2686                 if (!isdigit(*(o->data+num))) {
2687                         return -1;
2688                 }
2689         }
2690         /* reuse num (and save an int) */
2691         num=atoi(o->data);
2692         b_reset(o);
2693         return num;
2694 }
2695
2696 FILE *generate_stream_from_list(struct pipe *head)
2697 {
2698         FILE *pf;
2699 #if 1
2700         int pid, channel[2];
2701         if (pipe(channel)<0) perror_msg_and_die("pipe");
2702         pid=fork();
2703         if (pid<0) {
2704                 perror_msg_and_die("fork");
2705         } else if (pid==0) {
2706                 close(channel[0]);
2707                 if (channel[1] != 1) {
2708                         dup2(channel[1],1);
2709                         close(channel[1]);
2710                 }
2711 #if 0
2712 #define SURROGATE "surrogate response"
2713                 write(1,SURROGATE,sizeof(SURROGATE));
2714                 _exit(run_list(head));
2715 #else
2716                 _exit(run_list_real(head));   /* leaks memory */
2717 #endif
2718         }
2719         debug_printf("forked child %d\n",pid);
2720         close(channel[1]);
2721         pf = fdopen(channel[0],"r");
2722         debug_printf("pipe on FILE *%p\n",pf);
2723 #else
2724         free_pipe_list(head,0);
2725         pf=popen("echo surrogate response","r");
2726         debug_printf("started fake pipe on FILE *%p\n",pf);
2727 #endif
2728         return pf;
2729 }
2730
2731 /* this version hacked for testing purposes */
2732 /* return code is exit status of the process that is run. */
2733 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2734 {
2735         int retcode;
2736         o_string result=NULL_O_STRING;
2737         struct p_context inner;
2738         FILE *p;
2739         struct in_str pipe_str;
2740         initialize_context(&inner);
2741
2742         /* recursion to generate command */
2743         retcode = parse_stream(&result, &inner, input, subst_end);
2744         if (retcode != 0) return retcode;  /* syntax error or EOF */
2745         done_word(&result, &inner);
2746         done_pipe(&inner, PIPE_SEQ);
2747         b_free(&result);
2748
2749         p=generate_stream_from_list(inner.list_head);
2750         if (p==NULL) return 1;
2751         mark_open(fileno(p));
2752         setup_file_in_str(&pipe_str, p);
2753
2754         /* now send results of command back into original context */
2755         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2756         /* XXX In case of a syntax error, should we try to kill the child?
2757          * That would be tough to do right, so just read until EOF. */
2758         if (retcode == 1) {
2759                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2760         }
2761
2762         debug_printf("done reading from pipe, pclose()ing\n");
2763         /* This is the step that wait()s for the child.  Should be pretty
2764          * safe, since we just read an EOF from its stdout.  We could try
2765          * to better, by using wait(), and keeping track of background jobs
2766          * at the same time.  That would be a lot of work, and contrary
2767          * to the KISS philosophy of this program. */
2768         mark_closed(fileno(p));
2769         retcode=pclose(p);
2770         free_pipe_list(inner.list_head,0);
2771         debug_printf("pclosed, retcode=%d\n",retcode);
2772         /* XXX this process fails to trim a single trailing newline */
2773         return retcode;
2774 }
2775
2776 static int parse_group(o_string *dest, struct p_context *ctx,
2777         struct in_str *input, int ch)
2778 {
2779         int rcode, endch=0;
2780         struct p_context sub;
2781         struct child_prog *child = ctx->child;
2782         if (child->argv) {
2783                 syntax();
2784                 return 1;  /* syntax error, groups and arglists don't mix */
2785         }
2786         initialize_context(&sub);
2787         switch(ch) {
2788                 case '(': endch=')'; child->subshell=1; break;
2789                 case '{': endch='}'; break;
2790                 default: syntax();   /* really logic error */
2791         }
2792         rcode=parse_stream(dest,&sub,input,endch);
2793         done_word(dest,&sub); /* finish off the final word in the subcontext */
2794         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2795         child->group = sub.list_head;
2796         return rcode;
2797         /* child remains "open", available for possible redirects */
2798 }
2799 #endif
2800
2801 /* basically useful version until someone wants to get fancier,
2802  * see the bash man page under "Parameter Expansion" */
2803 static char *lookup_param(char *src)
2804 {
2805         char *p;
2806
2807         if (!src)
2808                 return NULL;
2809
2810                 p = getenv(src);
2811                 if (!p)
2812                         p = get_local_var(src);
2813
2814         return p;
2815 }
2816
2817 #ifdef __U_BOOT__
2818 static char *get_dollar_var(char ch)
2819 {
2820         static char buf[40];
2821
2822         buf[0] = '\0';
2823         switch (ch) {
2824                 case '?':
2825                         sprintf(buf, "%u", (unsigned int)last_return_code);
2826                         break;
2827                 default:
2828                         return NULL;
2829         }
2830         return buf;
2831 }
2832 #endif
2833
2834 /* return code: 0 for OK, 1 for syntax error */
2835 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2836 {
2837 #ifndef __U_BOOT__
2838         int i, advance=0;
2839 #else
2840         int advance=0;
2841 #endif
2842 #ifndef __U_BOOT__
2843         char sep[]=" ";
2844 #endif
2845         int ch = input->peek(input);  /* first character after the $ */
2846         debug_printf("handle_dollar: ch=%c\n",ch);
2847         if (isalpha(ch)) {
2848                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2849                 ctx->child->sp++;
2850                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2851                         b_getch(input);
2852                         b_addchr(dest,ch);
2853                 }
2854                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2855 #ifndef __U_BOOT__
2856         } else if (isdigit(ch)) {
2857                 i = ch-'0';  /* XXX is $0 special? */
2858                 if (i<global_argc) {
2859                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2860                 }
2861                 advance = 1;
2862 #endif
2863         } else switch (ch) {
2864 #ifndef __U_BOOT__
2865                 case '$':
2866                         b_adduint(dest,getpid());
2867                         advance = 1;
2868                         break;
2869                 case '!':
2870                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2871                         advance = 1;
2872                         break;
2873 #endif
2874                 case '?':
2875 #ifndef __U_BOOT__
2876                         b_adduint(dest,last_return_code);
2877 #else
2878                         ctx->child->sp++;
2879                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2880                         b_addchr(dest, '$');
2881                         b_addchr(dest, '?');
2882                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2883 #endif
2884                         advance = 1;
2885                         break;
2886 #ifndef __U_BOOT__
2887                 case '#':
2888                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2889                         advance = 1;
2890                         break;
2891 #endif
2892                 case '{':
2893                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2894                         ctx->child->sp++;
2895                         b_getch(input);
2896                         /* XXX maybe someone will try to escape the '}' */
2897                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2898                                 b_addchr(dest,ch);
2899                         }
2900                         if (ch != '}') {
2901                                 syntax();
2902                                 return 1;
2903                         }
2904                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2905                         break;
2906 #ifndef __U_BOOT__
2907                 case '(':
2908                         b_getch(input);
2909                         process_command_subs(dest, ctx, input, ')');
2910                         break;
2911                 case '*':
2912                         sep[0]=ifs[0];
2913                         for (i=1; i<global_argc; i++) {
2914                                 parse_string(dest, ctx, global_argv[i]);
2915                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2916                         }
2917                         break;
2918                 case '@':
2919                 case '-':
2920                 case '_':
2921                         /* still unhandled, but should be eventually */
2922                         error_msg("unhandled syntax: $%c",ch);
2923                         return 1;
2924                         break;
2925 #endif
2926                 default:
2927                         b_addqchr(dest,'$',dest->quote);
2928         }
2929         /* Eat the character if the flag was set.  If the compiler
2930          * is smart enough, we could substitute "b_getch(input);"
2931          * for all the "advance = 1;" above, and also end up with
2932          * a nice size-optimized program.  Hah!  That'll be the day.
2933          */
2934         if (advance) b_getch(input);
2935         return 0;
2936 }
2937
2938 #ifndef __U_BOOT__
2939 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2940 {
2941         struct in_str foo;
2942         setup_string_in_str(&foo, src);
2943         return parse_stream(dest, ctx, &foo, '\0');
2944 }
2945 #endif
2946
2947 /* return code is 0 for normal exit, 1 for syntax error */
2948 int parse_stream(o_string *dest, struct p_context *ctx,
2949         struct in_str *input, int end_trigger)
2950 {
2951         unsigned int ch, m;
2952 #ifndef __U_BOOT__
2953         int redir_fd;
2954         redir_type redir_style;
2955 #endif
2956         int next;
2957
2958         /* Only double-quote state is handled in the state variable dest->quote.
2959          * A single-quote triggers a bypass of the main loop until its mate is
2960          * found.  When recursing, quote state is passed in via dest->quote. */
2961
2962         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2963         while ((ch=b_getch(input))!=EOF) {
2964                 m = map[ch];
2965 #ifdef __U_BOOT__
2966                 if (input->__promptme == 0) return 1;
2967 #endif
2968                 next = (ch == '\n') ? 0 : b_peek(input);
2969
2970                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2971                         ch >= ' ' ? ch : '.', ch, m,
2972                         dest->quote, ctx->stack == NULL ? '*' : '.');
2973
2974                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2975                         b_addqchr(dest, ch, dest->quote);
2976                 } else {
2977                         if (m==2) {  /* unquoted IFS */
2978                                 if (done_word(dest, ctx)) {
2979                                         return 1;
2980                                 }
2981                                 /* If we aren't performing a substitution, treat a newline as a
2982                                  * command separator.  */
2983                                 if (end_trigger != '\0' && ch=='\n')
2984                                         done_pipe(ctx,PIPE_SEQ);
2985                         }
2986                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2987                                 debug_printf("leaving parse_stream (triggered)\n");
2988                                 return 0;
2989                         }
2990 #if 0
2991                         if (ch=='\n') {
2992                                 /* Yahoo!  Time to run with it! */
2993                                 done_pipe(ctx,PIPE_SEQ);
2994                                 run_list(ctx->list_head);
2995                                 initialize_context(ctx);
2996                         }
2997 #endif
2998                         if (m!=2) switch (ch) {
2999                 case '#':
3000                         if (dest->length == 0 && !dest->quote) {
3001                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
3002                         } else {
3003                                 b_addqchr(dest, ch, dest->quote);
3004                         }
3005                         break;
3006                 case '\\':
3007                         if (next == EOF) {
3008                                 syntax();
3009                                 return 1;
3010                         }
3011                         b_addqchr(dest, '\\', dest->quote);
3012                         b_addqchr(dest, b_getch(input), dest->quote);
3013                         break;
3014                 case '$':
3015                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3016                         break;
3017                 case '\'':
3018                         dest->nonnull = 1;
3019                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3020 #ifdef __U_BOOT__
3021                                 if(input->__promptme == 0) return 1;
3022 #endif
3023                                 b_addchr(dest,ch);
3024                         }
3025                         if (ch==EOF) {
3026                                 syntax();
3027                                 return 1;
3028                         }
3029                         break;
3030                 case '"':
3031                         dest->nonnull = 1;
3032                         dest->quote = !dest->quote;
3033                         break;
3034 #ifndef __U_BOOT__
3035                 case '`':
3036                         process_command_subs(dest, ctx, input, '`');
3037                         break;
3038                 case '>':
3039                         redir_fd = redirect_opt_num(dest);
3040                         done_word(dest, ctx);
3041                         redir_style=REDIRECT_OVERWRITE;
3042                         if (next == '>') {
3043                                 redir_style=REDIRECT_APPEND;
3044                                 b_getch(input);
3045                         } else if (next == '(') {
3046                                 syntax();   /* until we support >(list) Process Substitution */
3047                                 return 1;
3048                         }
3049                         setup_redirect(ctx, redir_fd, redir_style, input);
3050                         break;
3051                 case '<':
3052                         redir_fd = redirect_opt_num(dest);
3053                         done_word(dest, ctx);
3054                         redir_style=REDIRECT_INPUT;
3055                         if (next == '<') {
3056                                 redir_style=REDIRECT_HEREIS;
3057                                 b_getch(input);
3058                         } else if (next == '>') {
3059                                 redir_style=REDIRECT_IO;
3060                                 b_getch(input);
3061                         } else if (next == '(') {
3062                                 syntax();   /* until we support <(list) Process Substitution */
3063                                 return 1;
3064                         }
3065                         setup_redirect(ctx, redir_fd, redir_style, input);
3066                         break;
3067 #endif
3068                 case ';':
3069                         done_word(dest, ctx);
3070                         done_pipe(ctx,PIPE_SEQ);
3071                         break;
3072                 case '&':
3073                         done_word(dest, ctx);
3074                         if (next=='&') {
3075                                 b_getch(input);
3076                                 done_pipe(ctx,PIPE_AND);
3077                         } else {
3078 #ifndef __U_BOOT__
3079                                 done_pipe(ctx,PIPE_BG);
3080 #else
3081                                 syntax_err();
3082                                 return 1;
3083 #endif
3084                         }
3085                         break;
3086                 case '|':
3087                         done_word(dest, ctx);
3088                         if (next=='|') {
3089                                 b_getch(input);
3090                                 done_pipe(ctx,PIPE_OR);
3091                         } else {
3092                                 /* we could pick up a file descriptor choice here
3093                                  * with redirect_opt_num(), but bash doesn't do it.
3094                                  * "echo foo 2| cat" yields "foo 2". */
3095 #ifndef __U_BOOT__
3096                                 done_command(ctx);
3097 #else
3098                                 syntax_err();
3099                                 return 1;
3100 #endif
3101                         }
3102                         break;
3103 #ifndef __U_BOOT__
3104                 case '(':
3105                 case '{':
3106                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3107                         break;
3108                 case ')':
3109                 case '}':
3110                         syntax();   /* Proper use of this character caught by end_trigger */
3111                         return 1;
3112                         break;
3113 #endif
3114                 default:
3115                         syntax();   /* this is really an internal logic error */
3116                         return 1;
3117                         }
3118                 }
3119         }
3120         /* complain if quote?  No, maybe we just finished a command substitution
3121          * that was quoted.  Example:
3122          * $ echo "`cat foo` plus more"
3123          * and we just got the EOF generated by the subshell that ran "cat foo"
3124          * The only real complaint is if we got an EOF when end_trigger != '\0',
3125          * that is, we were really supposed to get end_trigger, and never got
3126          * one before the EOF.  Can't use the standard "syntax error" return code,
3127          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3128         debug_printf("leaving parse_stream (EOF)\n");
3129         if (end_trigger != '\0') return -1;
3130         return 0;
3131 }
3132
3133 void mapset(const unsigned char *set, int code)
3134 {
3135         const unsigned char *s;
3136         for (s=set; *s; s++) map[*s] = code;
3137 }
3138
3139 void update_ifs_map(void)
3140 {
3141         /* char *ifs and char map[256] are both globals. */
3142         ifs = (uchar *)getenv("IFS");
3143         if (ifs == NULL) ifs=(uchar *)" \t\n";
3144         /* Precompute a list of 'flow through' behavior so it can be treated
3145          * quickly up front.  Computation is necessary because of IFS.
3146          * Special case handling of IFS == " \t\n" is not implemented.
3147          * The map[] array only really needs two bits each, and on most machines
3148          * that would be faster because of the reduced L1 cache footprint.
3149          */
3150         memset(map,0,sizeof(map)); /* most characters flow through always */
3151 #ifndef __U_BOOT__
3152         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3153         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3154 #else
3155         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3156         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3157 #endif
3158         mapset(ifs, 2);            /* also flow through if quoted */
3159 }
3160
3161 /* most recursion does not come through here, the exeception is
3162  * from builtin_source() */
3163 int parse_stream_outer(struct in_str *inp, int flag)
3164 {
3165
3166         struct p_context ctx;
3167         o_string temp=NULL_O_STRING;
3168         int rcode;
3169 #ifdef __U_BOOT__
3170         int code = 0;
3171 #endif
3172         do {
3173                 ctx.type = flag;
3174                 initialize_context(&ctx);
3175                 update_ifs_map();
3176                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3177                 inp->promptmode=1;
3178                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3179 #ifdef __U_BOOT__
3180                 if (rcode == 1) flag_repeat = 0;
3181 #endif
3182                 if (rcode != 1 && ctx.old_flag != 0) {
3183                         syntax();
3184 #ifdef __U_BOOT__
3185                         flag_repeat = 0;
3186 #endif
3187                 }
3188                 if (rcode != 1 && ctx.old_flag == 0) {
3189                         done_word(&temp, &ctx);
3190                         done_pipe(&ctx,PIPE_SEQ);
3191 #ifndef __U_BOOT__
3192                         run_list(ctx.list_head);
3193 #else
3194                         code = run_list(ctx.list_head);
3195                         if (code == -2) {       /* exit */
3196                                 b_free(&temp);
3197                                 code = 0;
3198                                 /* XXX hackish way to not allow exit from main loop */
3199                                 if (inp->peek == file_peek) {
3200                                         printf("exit not allowed from main input shell.\n");
3201                                         continue;
3202                                 }
3203                                 break;
3204                         }
3205                         if (code == -1)
3206                             flag_repeat = 0;
3207 #endif
3208                 } else {
3209                         if (ctx.old_flag != 0) {
3210                                 free(ctx.stack);
3211                                 b_reset(&temp);
3212                         }
3213 #ifdef __U_BOOT__
3214                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3215                         inp->__promptme = 1;
3216 #endif
3217                         temp.nonnull = 0;
3218                         temp.quote = 0;
3219                         inp->p = NULL;
3220                         free_pipe_list(ctx.list_head,0);
3221                 }
3222                 b_free(&temp);
3223         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3224 #ifndef __U_BOOT__
3225         return 0;
3226 #else
3227         return (code != 0) ? 1 : 0;
3228 #endif /* __U_BOOT__ */
3229 }
3230
3231 #ifndef __U_BOOT__
3232 static int parse_string_outer(const char *s, int flag)
3233 #else
3234 int parse_string_outer(char *s, int flag)
3235 #endif  /* __U_BOOT__ */
3236 {
3237         struct in_str input;
3238 #ifdef __U_BOOT__
3239         char *p = NULL;
3240         int rcode;
3241         if ( !s || !*s)
3242                 return 1;
3243         if (!(p = strchr(s, '\n')) || *++p) {
3244                 p = xmalloc(strlen(s) + 2);
3245                 strcpy(p, s);
3246                 strcat(p, "\n");
3247                 setup_string_in_str(&input, p);
3248                 rcode = parse_stream_outer(&input, flag);
3249                 free(p);
3250                 return rcode;
3251         } else {
3252 #endif
3253         setup_string_in_str(&input, s);
3254         return parse_stream_outer(&input, flag);
3255 #ifdef __U_BOOT__
3256         }
3257 #endif
3258 }
3259
3260 #ifndef __U_BOOT__
3261 static int parse_file_outer(FILE *f)
3262 #else
3263 int parse_file_outer(void)
3264 #endif
3265 {
3266         int rcode;
3267         struct in_str input;
3268 #ifndef __U_BOOT__
3269         setup_file_in_str(&input, f);
3270 #else
3271         setup_file_in_str(&input);
3272 #endif
3273         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3274         return rcode;
3275 }
3276
3277 #ifdef __U_BOOT__
3278 static void u_boot_hush_reloc(void)
3279 {
3280         unsigned long addr;
3281         struct reserved_combo *r;
3282
3283         for (r=reserved_list; r<reserved_list+NRES; r++) {
3284                 addr = (ulong) (r->literal) + gd->reloc_off;
3285                 r->literal = (char *)addr;
3286         }
3287 }
3288
3289 int u_boot_hush_start(void)
3290 {
3291         if (top_vars == NULL) {
3292                 top_vars = malloc(sizeof(struct variables));
3293                 top_vars->name = "HUSH_VERSION";
3294                 top_vars->value = "0.01";
3295                 top_vars->next = 0;
3296                 top_vars->flg_export = 0;
3297                 top_vars->flg_read_only = 1;
3298                 u_boot_hush_reloc();
3299         }
3300         return 0;
3301 }
3302
3303 static void *xmalloc(size_t size)
3304 {
3305         void *p = NULL;
3306
3307         if (!(p = malloc(size))) {
3308             printf("ERROR : memory not allocated\n");
3309             for(;;);
3310         }
3311         return p;
3312 }
3313
3314 static void *xrealloc(void *ptr, size_t size)
3315 {
3316         void *p = NULL;
3317
3318         if (!(p = realloc(ptr, size))) {
3319             printf("ERROR : memory not allocated\n");
3320             for(;;);
3321         }
3322         return p;
3323 }
3324 #endif /* __U_BOOT__ */
3325
3326 #ifndef __U_BOOT__
3327 /* Make sure we have a controlling tty.  If we get started under a job
3328  * aware app (like bash for example), make sure we are now in charge so
3329  * we don't fight over who gets the foreground */
3330 static void setup_job_control(void)
3331 {
3332         static pid_t shell_pgrp;
3333         /* Loop until we are in the foreground.  */
3334         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3335                 kill (- shell_pgrp, SIGTTIN);
3336
3337         /* Ignore interactive and job-control signals.  */
3338         signal(SIGINT, SIG_IGN);
3339         signal(SIGQUIT, SIG_IGN);
3340         signal(SIGTERM, SIG_IGN);
3341         signal(SIGTSTP, SIG_IGN);
3342         signal(SIGTTIN, SIG_IGN);
3343         signal(SIGTTOU, SIG_IGN);
3344         signal(SIGCHLD, SIG_IGN);
3345
3346         /* Put ourselves in our own process group.  */
3347         setsid();
3348         shell_pgrp = getpid ();
3349         setpgid (shell_pgrp, shell_pgrp);
3350
3351         /* Grab control of the terminal.  */
3352         tcsetpgrp(shell_terminal, shell_pgrp);
3353 }
3354
3355 int hush_main(int argc, char **argv)
3356 {
3357         int opt;
3358         FILE *input;
3359         char **e = environ;
3360
3361         /* XXX what should these be while sourcing /etc/profile? */
3362         global_argc = argc;
3363         global_argv = argv;
3364
3365         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3366          * hush_main(), therefore we cannot rely on the BSS to zero out this
3367          * stuff.  Reset these to 0 every time. */
3368         ifs = NULL;
3369         /* map[] is taken care of with call to update_ifs_map() */
3370         fake_mode = 0;
3371         interactive = 0;
3372         close_me_head = NULL;
3373         last_bg_pid = 0;
3374         job_list = NULL;
3375         last_jobid = 0;
3376
3377         /* Initialize some more globals to non-zero values */
3378         set_cwd();
3379 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3380         cmdedit_set_initial_prompt();
3381 #else
3382         PS1 = NULL;
3383 #endif
3384         PS2 = "> ";
3385
3386         /* initialize our shell local variables with the values
3387          * currently living in the environment */
3388         if (e) {
3389                 for (; *e; e++)
3390                         set_local_var(*e, 2);   /* without call putenv() */
3391         }
3392
3393         last_return_code=EXIT_SUCCESS;
3394
3395
3396         if (argv[0] && argv[0][0] == '-') {
3397                 debug_printf("\nsourcing /etc/profile\n");
3398                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3399                         mark_open(fileno(input));
3400                         parse_file_outer(input);
3401                         mark_closed(fileno(input));
3402                         fclose(input);
3403                 }
3404         }
3405         input=stdin;
3406
3407         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3408                 switch (opt) {
3409                         case 'c':
3410                                 {
3411                                         global_argv = argv+optind;
3412                                         global_argc = argc-optind;
3413                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3414                                         goto final_return;
3415                                 }
3416                                 break;
3417                         case 'i':
3418                                 interactive++;
3419                                 break;
3420                         case 'f':
3421                                 fake_mode++;
3422                                 break;
3423                         default:
3424 #ifndef BB_VER
3425                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3426                                                 "   or: sh -c command [args]...\n\n");
3427                                 exit(EXIT_FAILURE);
3428 #else
3429                                 show_usage();
3430 #endif
3431                 }
3432         }
3433         /* A shell is interactive if the `-i' flag was given, or if all of
3434          * the following conditions are met:
3435          *        no -c command
3436          *    no arguments remaining or the -s flag given
3437          *    standard input is a terminal
3438          *    standard output is a terminal
3439          *    Refer to Posix.2, the description of the `sh' utility. */
3440         if (argv[optind]==NULL && input==stdin &&
3441                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3442                 interactive++;
3443         }
3444
3445         debug_printf("\ninteractive=%d\n", interactive);
3446         if (interactive) {
3447                 /* Looks like they want an interactive shell */
3448 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3449                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3450                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3451 #endif
3452                 setup_job_control();
3453         }
3454
3455         if (argv[optind]==NULL) {
3456                 opt=parse_file_outer(stdin);
3457                 goto final_return;
3458         }
3459
3460         debug_printf("\nrunning script '%s'\n", argv[optind]);
3461         global_argv = argv+optind;
3462         global_argc = argc-optind;
3463         input = xfopen(argv[optind], "r");
3464         opt = parse_file_outer(input);
3465
3466 #ifdef CONFIG_FEATURE_CLEAN_UP
3467         fclose(input);
3468         if (cwd && cwd != unknown)
3469                 free((char*)cwd);
3470         {
3471                 struct variables *cur, *tmp;
3472                 for(cur = top_vars; cur; cur = tmp) {
3473                         tmp = cur->next;
3474                         if (!cur->flg_read_only) {
3475                                 free(cur->name);
3476                                 free(cur->value);
3477                                 free(cur);
3478                         }
3479                 }
3480         }
3481 #endif
3482
3483 final_return:
3484         return(opt?opt:last_return_code);
3485 }
3486 #endif
3487
3488 static char *insert_var_value(char *inp)
3489 {
3490         int res_str_len = 0;
3491         int len;
3492         int done = 0;
3493         char *p, *p1, *res_str = NULL;
3494
3495         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3496                 if (p != inp) {
3497                         len = p - inp;
3498                         res_str = xrealloc(res_str, (res_str_len + len));
3499                         strncpy((res_str + res_str_len), inp, len);
3500                         res_str_len += len;
3501                 }
3502                 inp = ++p;
3503                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3504                 *p = '\0';
3505                 if ((p1 = lookup_param(inp))) {
3506                         len = res_str_len + strlen(p1);
3507                         res_str = xrealloc(res_str, (1 + len));
3508                         strcpy((res_str + res_str_len), p1);
3509                         res_str_len = len;
3510                 }
3511                 *p = SPECIAL_VAR_SYMBOL;
3512                 inp = ++p;
3513                 done = 1;
3514         }
3515         if (done) {
3516                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3517                 strcpy((res_str + res_str_len), inp);
3518                 while ((p = strchr(res_str, '\n'))) {
3519                         *p = ' ';
3520                 }
3521         }
3522         return (res_str == NULL) ? inp : res_str;
3523 }
3524
3525 static char **make_list_in(char **inp, char *name)
3526 {
3527         int len, i;
3528         int name_len = strlen(name);
3529         int n = 0;
3530         char **list;
3531         char *p1, *p2, *p3;
3532
3533         /* create list of variable values */
3534         list = xmalloc(sizeof(*list));
3535         for (i = 0; inp[i]; i++) {
3536                 p3 = insert_var_value(inp[i]);
3537                 p1 = p3;
3538                 while (*p1) {
3539                         if ((*p1 == ' ')) {
3540                                 p1++;
3541                                 continue;
3542                         }
3543                         if ((p2 = strchr(p1, ' '))) {
3544                                 len = p2 - p1;
3545                         } else {
3546                                 len = strlen(p1);
3547                                 p2 = p1 + len;
3548                         }
3549                         /* we use n + 2 in realloc for list,because we add
3550                          * new element and then we will add NULL element */
3551                         list = xrealloc(list, sizeof(*list) * (n + 2));
3552                         list[n] = xmalloc(2 + name_len + len);
3553                         strcpy(list[n], name);
3554                         strcat(list[n], "=");
3555                         strncat(list[n], p1, len);
3556                         list[n++][name_len + len + 1] = '\0';
3557                         p1 = p2;
3558                 }
3559                 if (p3 != inp[i]) free(p3);
3560         }
3561         list[n] = NULL;
3562         return list;
3563 }
3564
3565 /* Make new string for parser */
3566 static char * make_string(char ** inp)
3567 {
3568         char *p;
3569         char *str = NULL;
3570         int n;
3571         int len = 2;
3572
3573         for (n = 0; inp[n]; n++) {
3574                 p = insert_var_value(inp[n]);
3575                 str = xrealloc(str, (len + strlen(p)));
3576                 if (n) {
3577                         strcat(str, " ");
3578                 } else {
3579                         *str = '\0';
3580                 }
3581                 strcat(str, p);
3582                 len = strlen(str) + 3;
3583                 if (p != inp[n]) free(p);
3584         }
3585         len = strlen(str);
3586         *(str + len) = '\n';
3587         *(str + len + 1) = '\0';
3588         return str;
3589 }
3590
3591 #endif /* CFG_HUSH_PARSER */
3592 /****************************************************************************/