arrayfunc.c

   1 /* arrayfunc.c -- High-level array functions used by other parts of the shell. */
   2
   3 /* Copyright (C) 2001-2011 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "config.h"
  22
  23 #if defined (ARRAY_VARS)
  24
  25 #if defined (HAVE_UNISTD_H)
  26 #  include <unistd.h>
  27 #endif
  28 #include <stdio.h>
  29
  30 #include "bashintl.h"
  31
  32 #include "shell.h"
  33 #include "pathexp.h"
  34
  35 #include "shmbutil.h"
  36
  37 #include "builtins/common.h"
  38
  39 extern char *this_command_name;
  40 extern int last_command_exit_value;
  41 extern int array_needs_making;
  42
  43 static SHELL_VAR *bind_array_var_internal __P((SHELL_VAR *, arrayind_t, char *, char *, int));
  44 static SHELL_VAR *assign_array_element_internal __P((SHELL_VAR *, char *, char *, char *, int, char *, int));
  45
  46 static char *quote_assign __P((const char *));
  47 static void quote_array_assignment_chars __P((WORD_LIST *));
  48 static char *array_value_internal __P((char *, int, int, int *, arrayind_t *));
  49
  50 /* Standard error message to use when encountering an invalid array subscript */
  51 const char * const bash_badsub_errmsg = N_("bad array subscript");
  52
  53 /* **************************************************************** */
  54 /*                                                                  */
  55 /*  Functions to manipulate array variables and perform assignments */
  56 /*                                                                  */
  57 /* **************************************************************** */
  58
  59 /* Convert a shell variable to an array variable.  The original value is
  60    saved as array[0]. */
  61 SHELL_VAR *
  62 convert_var_to_array (var)
  63      SHELL_VAR *var;
  64 {
  65   char *oldval;
  66   ARRAY *array;
  67
  68   oldval = value_cell (var);
  69   array = array_create ();
  70   if (oldval)
  71     array_insert (array, 0, oldval);
  72
  73   FREE (value_cell (var));
  74   var_setarray (var, array);
  75
  76   /* these aren't valid anymore */
  77   var->dynamic_value = (sh_var_value_func_t *)NULL;
  78   var->assign_func = (sh_var_assign_func_t *)NULL;
  79
  80   INVALIDATE_EXPORTSTR (var);
  81   if (exported_p (var))
  82     array_needs_making++;
  83
  84   VSETATTR (var, att_array);
  85   VUNSETATTR (var, att_invisible);
  86
  87   return var;
  88 }
  89
  90 /* Convert a shell variable to an array variable.  The original value is
  91    saved as array[0]. */
  92 SHELL_VAR *
  93 convert_var_to_assoc (var)
  94      SHELL_VAR *var;
  95 {
  96   char *oldval;
  97   HASH_TABLE *hash;
  98
  99   oldval = value_cell (var);
 100   hash = assoc_create (0);
 101   if (oldval)
 102     assoc_insert (hash, savestring ("0"), oldval);
 103
 104   FREE (value_cell (var));
 105   var_setassoc (var, hash);
 106
 107   /* these aren't valid anymore */
 108   var->dynamic_value = (sh_var_value_func_t *)NULL;
 109   var->assign_func = (sh_var_assign_func_t *)NULL;
 110
 111   INVALIDATE_EXPORTSTR (var);
 112   if (exported_p (var))
 113     array_needs_making++;
 114
 115   VSETATTR (var, att_assoc);
 116   VUNSETATTR (var, att_invisible);
 117
 118   return var;
 119 }
 120
 121 char *
 122 make_array_variable_value (entry, ind, key, value, flags)
 123      SHELL_VAR *entry;
 124      arrayind_t ind;
 125      char *key;
 126      char *value;
 127      int flags;
 128 {
 129   SHELL_VAR *dentry;
 130   char *newval;
 131
 132   /* If we're appending, we need the old value of the array reference, so
 133      fake out make_variable_value with a dummy SHELL_VAR */
 134   if (flags & ASS_APPEND)
 135     {
 136       dentry = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
 137       dentry->name = savestring (entry->name);
 138       if (assoc_p (entry))
 139         newval = assoc_reference (assoc_cell (entry), key);
 140       else
 141         newval = array_reference (array_cell (entry), ind);
 142       if (newval)
 143         dentry->value = savestring (newval);
 144       else
 145         {
 146           dentry->value = (char *)xmalloc (1);
 147           dentry->value[0] = '\0';
 148         }
 149       dentry->exportstr = 0;
 150       dentry->attributes = entry->attributes & ~(att_array|att_assoc|att_exported);
 151       /* Leave the rest of the members uninitialized; the code doesn't look
 152          at them. */
 153       newval = make_variable_value (dentry, value, flags);
 154       dispose_variable (dentry);
 155     }
 156   else
 157     newval = make_variable_value (entry, value, flags);
 158
 159   return newval;
 160 }
 161
 162 static SHELL_VAR *
 163 bind_array_var_internal (entry, ind, key, value, flags)
 164      SHELL_VAR *entry;
 165      arrayind_t ind;
 166      char *key;
 167      char *value;
 168      int flags;
 169 {
 170   char *newval;
 171
 172   newval = make_array_variable_value (entry, ind, key, value, flags);
 173
 174   if (entry->assign_func)
 175     (*entry->assign_func) (entry, newval, ind, key);
 176   else if (assoc_p (entry))
 177     assoc_insert (assoc_cell (entry), key, newval);
 178   else
 179     array_insert (array_cell (entry), ind, newval);
 180   FREE (newval);
 181
 182   return (entry);
 183 }
 184
 185 /* Perform an array assignment name[ind]=value.  If NAME already exists and
 186    is not an array, and IND is 0, perform name=value instead.  If NAME exists
 187    and is not an array, and IND is not 0, convert it into an array with the
 188    existing value as name[0].
 189
 190    If NAME does not exist, just create an array variable, no matter what
 191    IND's value may be. */
 192 SHELL_VAR *
 193 bind_array_variable (name, ind, value, flags)
 194      char *name;
 195      arrayind_t ind;
 196      char *value;
 197      int flags;
 198 {
 199   SHELL_VAR *entry;
 200
 201   entry = find_shell_variable (name);
 202
 203   if (entry == (SHELL_VAR *) 0)
 204     entry = make_new_array_variable (name);
 205   else if (readonly_p (entry) || noassign_p (entry))
 206     {
 207       if (readonly_p (entry))
 208         err_readonly (name);
 209       return (entry);
 210     }
 211   else if (array_p (entry) == 0)
 212     entry = convert_var_to_array (entry);
 213
 214   /* ENTRY is an array variable, and ARRAY points to the value. */
 215   return (bind_array_var_internal (entry, ind, 0, value, flags));
 216 }
 217
 218 SHELL_VAR *
 219 bind_array_element (entry, ind, value, flags)
 220      SHELL_VAR *entry;
 221      arrayind_t ind;
 222      char *value;
 223      int flags;
 224 {
 225   return (bind_array_var_internal (entry, ind, 0, value, flags));
 226 }
 227
 228 SHELL_VAR *
 229 bind_assoc_variable (entry, name, key, value, flags)
 230      SHELL_VAR *entry;
 231      char *name;
 232      char *key;
 233      char *value;
 234      int flags;
 235 {
 236   SHELL_VAR *dentry;
 237   char *newval;
 238
 239   if (readonly_p (entry) || noassign_p (entry))
 240     {
 241       if (readonly_p (entry))
 242         err_readonly (name);
 243       return (entry);
 244     }
 245
 246   return (bind_array_var_internal (entry, 0, key, value, flags));
 247 }
 248
 249 /* Parse NAME, a lhs of an assignment statement of the form v[s], and
 250    assign VALUE to that array element by calling bind_array_variable(). */
 251 SHELL_VAR *
 252 assign_array_element (name, value, flags)
 253      char *name, *value;
 254      int flags;
 255 {
 256   char *sub, *vname;
 257   int sublen;
 258   SHELL_VAR *entry;
 259
 260   vname = array_variable_name (name, &sub, &sublen);
 261
 262   if (vname == 0)
 263     return ((SHELL_VAR *)NULL);
 264
 265   if ((ALL_ELEMENT_SUB (sub[0]) && sub[1] == ']') || (sublen <= 1))
 266     {
 267       free (vname);
 268       err_badarraysub (name);
 269       return ((SHELL_VAR *)NULL);
 270     }
 271
 272   entry = find_variable (vname);
 273   entry = assign_array_element_internal (entry, name, vname, sub, sublen, value, flags);
 274
 275   free (vname);
 276   return entry;
 277 }
 278
 279 static SHELL_VAR *
 280 assign_array_element_internal (entry, name, vname, sub, sublen, value, flags)
 281      SHELL_VAR *entry;
 282      char *name;                /* only used for error messages */
 283      char *vname;
 284      char *sub;
 285      int sublen;
 286      char *value;
 287      int flags;
 288 {
 289   char *akey;
 290   arrayind_t ind;
 291
 292   if (entry && assoc_p (entry))
 293     {
 294       sub[sublen-1] = '\0';
 295       akey = expand_assignment_string_to_string (sub, 0);       /* [ */
 296       sub[sublen-1] = ']';
 297       if (akey == 0 || *akey == 0)
 298         {
 299           err_badarraysub (name);
 300           FREE (akey);
 301           return ((SHELL_VAR *)NULL);
 302         }
 303       entry = bind_assoc_variable (entry, vname, akey, value, flags);
 304     }
 305   else
 306     {
 307       ind = array_expand_index (entry, sub, sublen);
 308       /* negative subscripts to indexed arrays count back from end */
 309       if (entry && ind < 0)
 310         ind = (array_p (entry) ? array_max_index (array_cell (entry)) : 0) + 1 + ind;
 311       if (ind < 0)
 312         {
 313           err_badarraysub (name);
 314           return ((SHELL_VAR *)NULL);
 315         }
 316       entry = bind_array_variable (vname, ind, value, flags);
 317     }
 318
 319   return (entry);
 320 }
 321
 322 /* Find the array variable corresponding to NAME.  If there is no variable,
 323    create a new array variable.  If the variable exists but is not an array,
 324    convert it to an indexed array.  If FLAGS&1 is non-zero, an existing
 325    variable is checked for the readonly or noassign attribute in preparation
 326    for assignment (e.g., by the `read' builtin).  If FLAGS&2 is non-zero, we
 327    create an associative array. */
 328 SHELL_VAR *
 329 find_or_make_array_variable (name, flags)
 330      char *name;
 331      int flags;
 332 {
 333   SHELL_VAR *var;
 334
 335   var = find_variable (name);
 336   if (var == 0)
 337     {
 338       /* See if we have a nameref pointing to a variable that hasn't been
 339          created yet. */
 340       var = find_variable_last_nameref (name);
 341       if (var && nameref_p (var))
 342         var = (flags & 2) ? make_new_assoc_variable (nameref_cell (var)) : make_new_array_variable (nameref_cell (var));
 343     }
 344
 345   if (var == 0)
 346     var = (flags & 2) ? make_new_assoc_variable (name) : make_new_array_variable (name);
 347   else if ((flags & 1) && (readonly_p (var) || noassign_p (var)))
 348     {
 349       if (readonly_p (var))
 350         err_readonly (name);
 351       return ((SHELL_VAR *)NULL);
 352     }
 353   else if ((flags & 2) && array_p (var))
 354     {
 355       last_command_exit_value = 1;
 356       report_error (_("%s: cannot convert indexed to associative array"), name);
 357       return ((SHELL_VAR *)NULL);
 358     }
 359   else if (array_p (var) == 0 && assoc_p (var) == 0)
 360     var = convert_var_to_array (var);
 361
 362   return (var);
 363 }
 364
 365 /* Perform a compound assignment statement for array NAME, where VALUE is
 366    the text between the parens:  NAME=( VALUE ) */
 367 SHELL_VAR *
 368 assign_array_from_string (name, value, flags)
 369      char *name, *value;
 370      int flags;
 371 {
 372   SHELL_VAR *var;
 373   int vflags;
 374
 375   vflags = 1;
 376   if (flags & ASS_MKASSOC)
 377     vflags |= 2;
 378
 379   var = find_or_make_array_variable (name, vflags);
 380   if (var == 0)
 381     return ((SHELL_VAR *)NULL);
 382
 383   return (assign_array_var_from_string (var, value, flags));
 384 }
 385
 386 /* Sequentially assign the indices of indexed array variable VAR from the
 387    words in LIST. */
 388 SHELL_VAR *
 389 assign_array_var_from_word_list (var, list, flags)
 390      SHELL_VAR *var;
 391      WORD_LIST *list;
 392      int flags;
 393 {
 394   register arrayind_t i;
 395   register WORD_LIST *l;
 396   ARRAY *a;
 397
 398   a = array_cell (var);
 399   i = (flags & ASS_APPEND) ? array_max_index (a) + 1 : 0;
 400
 401   for (l = list; l; l = l->next, i++)
 402     if (var->assign_func)
 403       (*var->assign_func) (var, l->word->word, i, 0);
 404     else
 405       array_insert (a, i, l->word->word);
 406   return var;
 407 }
 408
 409 WORD_LIST *
 410 expand_compound_array_assignment (var, value, flags)
 411      SHELL_VAR *var;
 412      char *value;
 413      int flags;
 414 {
 415   WORD_LIST *list, *nlist;
 416   WORD_LIST *hd, *tl, *t, *n;
 417   char *val;
 418   int ni;
 419
 420   /* This condition is true when invoked from the declare builtin with a
 421      command like
 422         declare -a d='([1]="" [2]="bdef" [5]="hello world" "test")' */
 423   if (*value == '(')    /*)*/
 424     {
 425       ni = 1;
 426       val = extract_array_assignment_list (value, &ni);
 427       if (val == 0)
 428         return (WORD_LIST *)NULL;
 429     }
 430   else
 431     val = value;
 432
 433   /* Expand the value string into a list of words, performing all the
 434      shell expansions including pathname generation and word splitting. */
 435   /* First we split the string on whitespace, using the shell parser
 436      (ksh93 seems to do this). */
 437   list = parse_string_to_word_list (val, 1, "array assign");
 438
 439   if (var && assoc_p (var))
 440     {
 441       if (val != value)
 442         free (val);
 443       return list;
 444     }
 445
 446   /* If we're using [subscript]=value, we need to quote each [ and ] to
 447      prevent unwanted filename expansion.  This doesn't need to be done
 448      for associative array expansion, since that uses a different expansion
 449      function (see assign_compound_array_list below). */
 450   if (list)
 451     quote_array_assignment_chars (list);
 452
 453   /* Now that we've split it, perform the shell expansions on each
 454      word in the list. */
 455   nlist = list ? expand_words_no_vars (list) : (WORD_LIST *)NULL;
 456
 457   dispose_words (list);
 458
 459   if (val != value)
 460     free (val);
 461
 462   return nlist;
 463 }
 464
 465 /* Callers ensure that VAR is not NULL */
 466 void
 467 assign_compound_array_list (var, nlist, flags)
 468      SHELL_VAR *var;
 469      WORD_LIST *nlist;
 470      int flags;
 471 {
 472   ARRAY *a;
 473   HASH_TABLE *h;
 474   WORD_LIST *list;
 475   char *w, *val, *nval;
 476   int len, iflags, free_val;
 477   arrayind_t ind, last_ind;
 478   char *akey;
 479
 480   a = (var && array_p (var)) ? array_cell (var) : (ARRAY *)0;
 481   h = (var && assoc_p (var)) ? assoc_cell (var) : (HASH_TABLE *)0;
 482
 483   akey = (char *)0;
 484   ind = 0;
 485
 486   /* Now that we are ready to assign values to the array, kill the existing
 487      value. */
 488   if ((flags & ASS_APPEND) == 0)
 489     {
 490       if (a && array_p (var))
 491         array_flush (a);
 492       else if (h && assoc_p (var))
 493         assoc_flush (h);
 494     }
 495
 496   last_ind = (a && (flags & ASS_APPEND)) ? array_max_index (a) + 1 : 0;
 497
 498   for (list = nlist; list; list = list->next)
 499     {
 500       iflags = flags;
 501       w = list->word->word;
 502
 503       /* We have a word of the form [ind]=value */
 504       if ((list->word->flags & W_ASSIGNMENT) && w[0] == '[')
 505         {
 506           /* Don't have to handle embedded quotes specially any more, since
 507              associative array subscripts have not been expanded yet (see
 508              above). */
 509           len = skipsubscript (w, 0, 0);
 510
 511           /* XXX - changes for `+=' */
 512           if (w[len] != ']' || (w[len+1] != '=' && (w[len+1] != '+' || w[len+2] != '=')))
 513             {
 514               if (assoc_p (var))
 515                 {
 516                   err_badarraysub (w);
 517                   continue;
 518                 }
 519               nval = make_variable_value (var, w, flags);
 520               if (var->assign_func)
 521                 (*var->assign_func) (var, nval, last_ind, 0);
 522               else
 523                 array_insert (a, last_ind, nval);
 524               FREE (nval);
 525               last_ind++;
 526               continue;
 527             }
 528
 529           if (len == 1)
 530             {
 531               err_badarraysub (w);
 532               continue;
 533             }
 534
 535           if (ALL_ELEMENT_SUB (w[1]) && len == 2)
 536             {
 537               last_command_exit_value = 1;
 538               if (assoc_p (var))
 539                 report_error (_("%s: invalid associative array key"), w);
 540               else
 541                 report_error (_("%s: cannot assign to non-numeric index"), w);
 542               continue;
 543             }
 544
 545           if (array_p (var))
 546             {
 547               ind = array_expand_index (var, w + 1, len);
 548               /* negative subscripts to indexed arrays count back from end */
 549               if (ind < 0)
 550                 ind = array_max_index (array_cell (var)) + 1 + ind;
 551               if (ind < 0)
 552                 {
 553                   err_badarraysub (w);
 554                   continue;
 555                 }
 556
 557               last_ind = ind;
 558             }
 559           else if (assoc_p (var))
 560             {
 561               /* This is not performed above, see expand_compound_array_assignment */
 562               w[len] = '\0';    /*[*/
 563               akey = expand_assignment_string_to_string (w+1, 0);
 564               w[len] = ']';
 565               /* And we need to expand the value also, see below */
 566               if (akey == 0 || *akey == 0)
 567                 {
 568                   err_badarraysub (w);
 569                   FREE (akey);
 570                   continue;
 571                 }
 572             }
 573
 574           /* XXX - changes for `+=' -- just accept the syntax.  ksh93 doesn't do this */
 575           if (w[len + 1] == '+' && w[len + 2] == '=')
 576             {
 577               iflags |= ASS_APPEND;
 578               val = w + len + 3;
 579             }
 580           else
 581             val = w + len + 2;
 582         }
 583       else if (assoc_p (var))
 584         {
 585           last_command_exit_value = 1;
 586           report_error (_("%s: %s: must use subscript when assigning associative array"), var->name, w);
 587           continue;
 588         }
 589       else              /* No [ind]=value, just a stray `=' */
 590         {
 591           ind = last_ind;
 592           val = w;
 593         }
 594
 595       free_val = 0;
 596       /* See above; we need to expand the value here */
 597       if (assoc_p (var))
 598         {
 599           val = expand_assignment_string_to_string (val, 0);
 600           free_val = 1;
 601         }
 602
 603       if (integer_p (var))
 604         this_command_name = (char *)NULL;       /* no command name for errors */
 605       bind_array_var_internal (var, ind, akey, val, iflags);
 606       last_ind++;
 607
 608       if (free_val)
 609         free (val);
 610     }
 611 }
 612
 613 /* Perform a compound array assignment:  VAR->name=( VALUE ).  The
 614    VALUE has already had the parentheses stripped. */
 615 SHELL_VAR *
 616 assign_array_var_from_string (var, value, flags)
 617      SHELL_VAR *var;
 618      char *value;
 619      int flags;
 620 {
 621   WORD_LIST *nlist;
 622
 623   if (value == 0)
 624     return var;
 625
 626   nlist = expand_compound_array_assignment (var, value, flags);
 627   assign_compound_array_list (var, nlist, flags);
 628
 629   if (nlist)
 630     dispose_words (nlist);
 631   return (var);
 632 }
 633
 634 /* Quote globbing chars and characters in $IFS before the `=' in an assignment
 635    statement (usually a compound array assignment) to protect them from
 636    unwanted filename expansion or word splitting. */
 637 static char *
 638 quote_assign (string)
 639      const char *string;
 640 {
 641   size_t slen;
 642   int saw_eq;
 643   char *temp, *t, *subs;
 644   const char *s, *send;
 645   int ss, se;
 646   DECLARE_MBSTATE;
 647
 648   slen = strlen (string);
 649   send = string + slen;
 650
 651   t = temp = (char *)xmalloc (slen * 2 + 1);
 652   saw_eq = 0;
 653   for (s = string; *s; )
 654     {
 655       if (*s == '=')
 656         saw_eq = 1;
 657       if (saw_eq == 0 && *s == '[')             /* looks like a subscript */
 658         {
 659           ss = s - string;
 660           se = skipsubscript (string, ss, 0);
 661           subs = substring (s, ss, se);
 662           *t++ = '\\';
 663           strcpy (t, subs);
 664           t += se - ss;
 665           *t++ = '\\';
 666           *t++ = ']';
 667           s += se + 1;
 668           free (subs);
 669           continue;
 670         }
 671       if (saw_eq == 0 && (glob_char_p (s) || isifs (*s)))
 672         *t++ = '\\';
 673
 674       COPY_CHAR_P (t, s, send);
 675     }
 676   *t = '\0';
 677   return temp;
 678 }
 679
 680 /* For each word in a compound array assignment, if the word looks like
 681    [ind]=value, quote globbing chars and characters in $IFS before the `='. */
 682 static void
 683 quote_array_assignment_chars (list)
 684      WORD_LIST *list;
 685 {
 686   char *nword;
 687   WORD_LIST *l;
 688
 689   for (l = list; l; l = l->next)
 690     {
 691       if (l->word == 0 || l->word->word == 0 || l->word->word[0] == '\0')
 692         continue;       /* should not happen, but just in case... */
 693       /* Don't bother if it hasn't been recognized as an assignment or
 694          doesn't look like [ind]=value */
 695       if ((l->word->flags & W_ASSIGNMENT) == 0)
 696         continue;
 697       if (l->word->word[0] != '[' || mbschr (l->word->word, '=') == 0) /* ] */
 698         continue;
 699
 700       nword = quote_assign (l->word->word);
 701       free (l->word->word);
 702       l->word->word = nword;
 703       l->word->flags |= W_NOGLOB;       /* XXX - W_NOSPLIT also? */
 704     }
 705 }
 706
 707 /* skipsubscript moved to subst.c to use private functions. 2009/02/24. */
 708
 709 /* This function is called with SUB pointing to just after the beginning
 710    `[' of an array subscript and removes the array element to which SUB
 711    expands from array VAR.  A subscript of `*' or `@' unsets the array. */
 712 int
 713 unbind_array_element (var, sub)
 714      SHELL_VAR *var;
 715      char *sub;
 716 {
 717   int len;
 718   arrayind_t ind;
 719   char *akey;
 720   ARRAY_ELEMENT *ae;
 721
 722   len = skipsubscript (sub, 0, 0);
 723   if (sub[len] != ']' || len == 0)
 724     {
 725       builtin_error ("%s[%s: %s", var->name, sub, _(bash_badsub_errmsg));
 726       return -1;
 727     }
 728   sub[len] = '\0';
 729
 730   if (ALL_ELEMENT_SUB (sub[0]) && sub[1] == 0)
 731     {
 732       unbind_variable (var->name);
 733       return (0);
 734     }
 735
 736   if (assoc_p (var))
 737     {
 738       akey = expand_assignment_string_to_string (sub, 0);     /* [ */
 739       if (akey == 0 || *akey == 0)
 740         {
 741           builtin_error ("[%s]: %s", sub, _(bash_badsub_errmsg));
 742           FREE (akey);
 743           return -1;
 744         }
 745       assoc_remove (assoc_cell (var), akey);
 746       free (akey);
 747     }
 748   else
 749     {
 750       ind = array_expand_index (var, sub, len+1);
 751       /* negative subscripts to indexed arrays count back from end */
 752       if (ind < 0)
 753         ind = array_max_index (array_cell (var)) + 1 + ind;
 754       if (ind < 0)
 755         {
 756           builtin_error ("[%s]: %s", sub, _(bash_badsub_errmsg));
 757           return -1;
 758         }
 759       ae = array_remove (array_cell (var), ind);
 760       if (ae)
 761         array_dispose_element (ae);
 762     }
 763
 764   return 0;
 765 }
 766
 767 /* Format and output an array assignment in compound form VAR=(VALUES),
 768    suitable for re-use as input. */
 769 void
 770 print_array_assignment (var, quoted)
 771      SHELL_VAR *var;
 772      int quoted;
 773 {
 774   char *vstr;
 775
 776   vstr = array_to_assign (array_cell (var), quoted);
 777
 778   if (vstr == 0)
 779     printf ("%s=%s\n", var->name, quoted ? "'()'" : "()");
 780   else
 781     {
 782       printf ("%s=%s\n", var->name, vstr);
 783       free (vstr);
 784     }
 785 }
 786
 787 /* Format and output an associative array assignment in compound form
 788    VAR=(VALUES), suitable for re-use as input. */
 789 void
 790 print_assoc_assignment (var, quoted)
 791      SHELL_VAR *var;
 792      int quoted;
 793 {
 794   char *vstr;
 795
 796   vstr = assoc_to_assign (assoc_cell (var), quoted);
 797
 798   if (vstr == 0)
 799     printf ("%s=%s\n", var->name, quoted ? "'()'" : "()");
 800   else
 801     {
 802       printf ("%s=%s\n", var->name, vstr);
 803       free (vstr);
 804     }
 805 }
 806
 807 /***********************************************************************/
 808 /*                                                                     */
 809 /* Utility functions to manage arrays and their contents for expansion */
 810 /*                                                                     */
 811 /***********************************************************************/
 812
 813 /* Return 1 if NAME is a properly-formed array reference v[sub]. */
 814 int
 815 valid_array_reference (name)
 816      char *name;
 817 {
 818   char *t;
 819   int r, len;
 820
 821   t = mbschr (name, '[');       /* ] */
 822   if (t)
 823     {
 824       *t = '\0';
 825       r = legal_identifier (name);
 826       *t = '[';
 827       if (r == 0)
 828         return 0;
 829       /* Check for a properly-terminated non-blank subscript. */
 830       len = skipsubscript (t, 0, 0);
 831       if (t[len] != ']' || len == 1)
 832         return 0;
 833       for (r = 1; r < len; r++)
 834         if (whitespace (t[r]) == 0)
 835           return 1;
 836       return 0;
 837     }
 838   return 0;
 839 }
 840
 841 /* Expand the array index beginning at S and extending LEN characters. */
 842 arrayind_t
 843 array_expand_index (var, s, len)
 844      SHELL_VAR *var;
 845      char *s;
 846      int len;
 847 {
 848   char *exp, *t;
 849   int expok;
 850   arrayind_t val;
 851
 852   exp = (char *)xmalloc (len);
 853   strncpy (exp, s, len - 1);
 854   exp[len - 1] = '\0';
 855   t = expand_arith_string (exp, 0);
 856   this_command_name = (char *)NULL;
 857   val = evalexp (t, &expok);
 858   free (t);
 859   free (exp);
 860   if (expok == 0)
 861     {
 862       last_command_exit_value = EXECUTION_FAILURE;
 863
 864       top_level_cleanup ();
 865       jump_to_top_level (DISCARD);
 866     }
 867   return val;
 868 }
 869
 870 /* Return the name of the variable specified by S without any subscript.
 871    If SUBP is non-null, return a pointer to the start of the subscript
 872    in *SUBP. If LENP is non-null, the length of the subscript is returned
 873    in *LENP.  This returns newly-allocated memory. */
 874 char *
 875 array_variable_name (s, subp, lenp)
 876      char *s, **subp;
 877      int *lenp;
 878 {
 879   char *t, *ret;
 880   int ind, ni;
 881
 882   t = mbschr (s, '[');
 883   if (t == 0)
 884     {
 885       if (subp)
 886         *subp = t;
 887       if (lenp)
 888         *lenp = 0;
 889       return ((char *)NULL);
 890     }
 891   ind = t - s;
 892   ni = skipsubscript (s, ind, 0);
 893   if (ni <= ind + 1 || s[ni] != ']')
 894     {
 895       err_badarraysub (s);
 896       if (subp)
 897         *subp = t;
 898       if (lenp)
 899         *lenp = 0;
 900       return ((char *)NULL);
 901     }
 902
 903   *t = '\0';
 904   ret = savestring (s);
 905   *t++ = '[';           /* ] */
 906
 907   if (subp)
 908     *subp = t;
 909   if (lenp)
 910     *lenp = ni - ind;
 911
 912   return ret;
 913 }
 914
 915 /* Return the variable specified by S without any subscript.  If SUBP is
 916    non-null, return a pointer to the start of the subscript in *SUBP.
 917    If LENP is non-null, the length of the subscript is returned in *LENP. */
 918 SHELL_VAR *
 919 array_variable_part (s, subp, lenp)
 920      char *s, **subp;
 921      int *lenp;
 922 {
 923   char *t;
 924   SHELL_VAR *var;
 925
 926   t = array_variable_name (s, subp, lenp);
 927   if (t == 0)
 928     return ((SHELL_VAR *)NULL);
 929   var = find_variable (t);
 930
 931   free (t);
 932 #if 0
 933   return (var == 0 || invisible_p (var)) ? (SHELL_VAR *)0 : var;
 934 #else
 935   return var;   /* now return invisible variables; caller must handle */
 936 #endif
 937 }
 938
 939 #define INDEX_ERROR() \
 940   do \
 941     { \
 942       if (var) \
 943         err_badarraysub (var->name); \
 944       else \
 945         { \
 946           t[-1] = '\0'; \
 947           err_badarraysub (s); \
 948           t[-1] = '[';  /* ] */\
 949         } \
 950       return ((char *)NULL); \
 951     } \
 952   while (0)
 953
 954 /* Return a string containing the elements in the array and subscript
 955    described by S.  If the subscript is * or @, obeys quoting rules akin
 956    to the expansion of $* and $@ including double quoting.  If RTYPE
 957    is non-null it gets 1 if the array reference is name[*], 2 if the
 958    reference is name[@], and 0 otherwise. */
 959 static char *
 960 array_value_internal (s, quoted, flags, rtype, indp)
 961      char *s;
 962      int quoted, flags, *rtype;
 963      arrayind_t *indp;
 964 {
 965   int len;
 966   arrayind_t ind;
 967   char *akey;
 968   char *retval, *t, *temp;
 969   WORD_LIST *l;
 970   SHELL_VAR *var;
 971
 972   var = array_variable_part (s, &t, &len);
 973
 974   /* Expand the index, even if the variable doesn't exist, in case side
 975      effects are needed, like ${w[i++]} where w is unset. */
 976 #if 0
 977   if (var == 0)
 978     return (char *)NULL;
 979 #endif
 980
 981   if (len == 0)
 982     return ((char *)NULL);      /* error message already printed */
 983
 984   /* [ */
 985   akey = 0;
 986   if (ALL_ELEMENT_SUB (t[0]) && t[1] == ']')
 987     {
 988       if (rtype)
 989         *rtype = (t[0] == '*') ? 1 : 2;
 990       if ((flags & AV_ALLOWALL) == 0)
 991         {
 992           err_badarraysub (s);
 993           return ((char *)NULL);
 994         }
 995       else if (var == 0 || value_cell (var) == 0)       /* XXX - check for invisible_p(var) ? */
 996         return ((char *)NULL);
 997       else if (array_p (var) == 0 && assoc_p (var) == 0)
 998         l = add_string_to_list (value_cell (var), (WORD_LIST *)NULL);
 999       else if (assoc_p (var))
1000         {
1001           l = assoc_to_word_list (assoc_cell (var));
1002           if (l == (WORD_LIST *)NULL)
1003             return ((char *)NULL);
1004         }
1005       else
1006         {
1007           l = array_to_word_list (array_cell (var));
1008           if (l == (WORD_LIST *)NULL)
1009             return ((char *) NULL);
1010         }
1011
1012       if (t[0] == '*' && (quoted & (Q_HERE_DOCUMENT|Q_DOUBLE_QUOTES)))
1013         {
1014           temp = string_list_dollar_star (l);
1015           retval = quote_string (temp);         /* XXX - leak here */
1016           free (temp);
1017         }
1018       else      /* ${name[@]} or unquoted ${name[*]} */
1019         retval = string_list_dollar_at (l, quoted);     /* XXX - leak here */
1020
1021       dispose_words (l);
1022     }
1023   else
1024     {
1025       if (rtype)
1026         *rtype = 0;
1027       if (var == 0 || array_p (var) || assoc_p (var) == 0)
1028         {
1029           if ((flags & AV_USEIND) == 0 || indp == 0)
1030             {
1031               ind = array_expand_index (var, t, len);
1032               if (ind < 0)
1033                 {
1034                   /* negative subscripts to indexed arrays count back from end */
1035                   if (var && array_p (var))
1036                     ind = array_max_index (array_cell (var)) + 1 + ind;
1037                   if (ind < 0)
1038                     INDEX_ERROR();
1039                 }
1040               if (indp)
1041                 *indp = ind;
1042             }
1043           else if (indp)
1044             ind = *indp;
1045         }
1046       else if (assoc_p (var))
1047         {
1048           t[len - 1] = '\0';
1049           akey = expand_assignment_string_to_string (t, 0);     /* [ */
1050           t[len - 1] = ']';
1051           if (akey == 0 || *akey == 0)
1052             {
1053               FREE (akey);
1054               INDEX_ERROR();
1055             }
1056         }
1057
1058       if (var == 0 || value_cell (var) == 0)    /* XXX - check invisible_p(var) ? */
1059         {
1060           FREE (akey);
1061           return ((char *)NULL);
1062         }
1063       if (array_p (var) == 0 && assoc_p (var) == 0)
1064         return (ind == 0 ? value_cell (var) : (char *)NULL);
1065       else if (assoc_p (var))
1066         {
1067           retval = assoc_reference (assoc_cell (var), akey);
1068           free (akey);
1069         }
1070       else
1071         retval = array_reference (array_cell (var), ind);
1072     }
1073
1074   return retval;
1075 }
1076
1077 /* Return a string containing the elements described by the array and
1078    subscript contained in S, obeying quoting for subscripts * and @. */
1079 char *
1080 array_value (s, quoted, flags, rtype, indp)
1081      char *s;
1082      int quoted, flags, *rtype;
1083      arrayind_t *indp;
1084 {
1085   return (array_value_internal (s, quoted, flags|AV_ALLOWALL, rtype, indp));
1086 }
1087
1088 /* Return the value of the array indexing expression S as a single string.
1089    If (FLAGS & AV_ALLOWALL) is 0, do not allow `@' and `*' subscripts.  This
1090    is used by other parts of the shell such as the arithmetic expression
1091    evaluator in expr.c. */
1092 char *
1093 get_array_value (s, flags, rtype, indp)
1094      char *s;
1095      int flags, *rtype;
1096      arrayind_t *indp;
1097 {
1098   return (array_value_internal (s, 0, flags, rtype, indp));
1099 }
1100
1101 char *
1102 array_keys (s, quoted)
1103      char *s;
1104      int quoted;
1105 {
1106   int len;
1107   char *retval, *t, *temp;
1108   WORD_LIST *l;
1109   SHELL_VAR *var;
1110
1111   var = array_variable_part (s, &t, &len);
1112
1113   /* [ */
1114   if (var == 0 || ALL_ELEMENT_SUB (t[0]) == 0 || t[1] != ']')
1115     return (char *)NULL;
1116
1117   if (var_isset (var) == 0 || invisible_p (var))
1118     return (char *)NULL;
1119
1120   if (array_p (var) == 0 && assoc_p (var) == 0)
1121     l = add_string_to_list ("0", (WORD_LIST *)NULL);
1122   else if (assoc_p (var))
1123     l = assoc_keys_to_word_list (assoc_cell (var));
1124   else
1125     l = array_keys_to_word_list (array_cell (var));
1126   if (l == (WORD_LIST *)NULL)
1127     return ((char *) NULL);
1128
1129   if (t[0] == '*' && (quoted & (Q_HERE_DOCUMENT|Q_DOUBLE_QUOTES)))
1130     {
1131       temp = string_list_dollar_star (l);
1132       retval = quote_string (temp);
1133       free (temp);
1134     }
1135   else  /* ${!name[@]} or unquoted ${!name[*]} */
1136     retval = string_list_dollar_at (l, quoted);
1137
1138   dispose_words (l);
1139   return retval;
1140 }
1141 #endif /* ARRAY_VARS */