builtins/declare.def

   1 This file is declare.def, from which is created declare.c.
   2 It implements the builtins "declare" and "local" in Bash.
   3
   4 Copyright (C) 1987-2004 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Bash, the Bourne Again SHell.
   7
   8 Bash is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with Bash; see the file COPYING.  If not, write to the Free Software
  20 Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
  21
  22 $PRODUCES declare.c
  23
  24 $BUILTIN declare
  25 $FUNCTION declare_builtin
  26 $SHORT_DOC declare [-afFirtx] [-p] [name[=value] ...]
  27 Declare variables and/or give them attributes.  If no NAMEs are
  28 given, then display the values of variables instead.  The -p option
  29 will display the attributes and values of each NAME.
  30
  31 The flags are:
  32
  33   -a    to make NAMEs arrays (if supported)
  34   -f    to select from among function names only
  35   -F    to display function names (and line number and source file name if
  36         debugging) without definitions
  37   -i    to make NAMEs have the `integer' attribute
  38   -r    to make NAMEs readonly
  39   -t    to make NAMEs have the `trace' attribute
  40   -x    to make NAMEs export
  41
  42 Variables with the integer attribute have arithmetic evaluation (see
  43 `let') done when the variable is assigned to.
  44
  45 When displaying values of variables, -f displays a function's name
  46 and definition.  The -F option restricts the display to function
  47 name only.
  48
  49 Using `+' instead of `-' turns off the given attribute instead.  When
  50 used in a function, makes NAMEs local, as with the `local' command.
  51 $END
  52
  53 $BUILTIN typeset
  54 $FUNCTION declare_builtin
  55 $SHORT_DOC typeset [-afFirtx] [-p] name[=value] ...
  56 Obsolete.  See `declare'.
  57 $END
  58
  59 #include <config.h>
  60
  61 #if defined (HAVE_UNISTD_H)
  62 #  ifdef _MINIX
  63 #    include <sys/types.h>
  64 #  endif
  65 #  include <unistd.h>
  66 #endif
  67
  68 #include <stdio.h>
  69
  70 #include "../bashansi.h"
  71 #include "../bashintl.h"
  72
  73 #include "../shell.h"
  74 #include "common.h"
  75 #include "builtext.h"
  76 #include "bashgetopt.h"
  77
  78 extern int array_needs_making;
  79
  80 static int declare_internal __P((register WORD_LIST *, int));
  81
  82 /* Declare or change variable attributes. */
  83 int
  84 declare_builtin (list)
  85      register WORD_LIST *list;
  86 {
  87   return (declare_internal (list, 0));
  88 }
  89
  90 $BUILTIN local
  91 $FUNCTION local_builtin
  92 $SHORT_DOC local name[=value] ...
  93 Create a local variable called NAME, and give it VALUE.  LOCAL
  94 can only be used within a function; it makes the variable NAME
  95 have a visible scope restricted to that function and its children.
  96 $END
  97 int
  98 local_builtin (list)
  99      register WORD_LIST *list;
 100 {
 101   if (variable_context)
 102     return (declare_internal (list, 1));
 103   else
 104     {
 105       builtin_error (_("can only be used in a function"));
 106       return (EXECUTION_FAILURE);
 107     }
 108 }
 109
 110 #if defined (ARRAY_VARS)
 111 #  define DECLARE_OPTS  "+afiprtxF"
 112 #else
 113 #  define DECLARE_OPTS  "+fiprtxF"
 114 #endif
 115
 116 /* The workhorse function. */
 117 static int
 118 declare_internal (list, local_var)
 119      register WORD_LIST *list;
 120      int local_var;
 121 {
 122   int flags_on, flags_off, *flags, any_failed, assign_error, pflag, nodefs, opt;
 123   char *t, *subscript_start;
 124   SHELL_VAR *var;
 125   FUNCTION_DEF *shell_fn;
 126
 127   flags_on = flags_off = any_failed = assign_error = pflag = nodefs = 0;
 128   reset_internal_getopt ();
 129   while ((opt = internal_getopt (list, DECLARE_OPTS)) != EOF)
 130     {
 131       flags = list_opttype == '+' ? &flags_off : &flags_on;
 132
 133       switch (opt)
 134         {
 135         case 'a':
 136 #if defined (ARRAY_VARS)
 137           *flags |= att_array;
 138 #endif
 139           break;
 140         case 'p':
 141           if (local_var == 0)
 142             pflag++;
 143           break;
 144         case 'F':
 145           nodefs++;
 146           *flags |= att_function;
 147           break;
 148         case 'f':
 149           *flags |= att_function;
 150           break;
 151         case 'i':
 152           *flags |= att_integer;
 153           break;
 154         case 'r':
 155           *flags |= att_readonly;
 156           break;
 157         case 't':
 158           *flags |= att_trace;
 159           break;
 160         case 'x':
 161           *flags |= att_exported;
 162           array_needs_making = 1;
 163           break;
 164         default:
 165           builtin_usage ();
 166           return (EX_USAGE);
 167         }
 168     }
 169
 170   list = loptend;
 171
 172   /* If there are no more arguments left, then we just want to show
 173      some variables. */
 174   if (list == 0)        /* declare -[afFirtx] */
 175     {
 176       /* Show local variables defined at this context level if this is
 177          the `local' builtin. */
 178       if (local_var)
 179         {
 180           register SHELL_VAR **vlist;
 181           register int i;
 182
 183           vlist = all_local_variables ();
 184
 185           if (vlist)
 186             {
 187               for (i = 0; vlist[i]; i++)
 188                 print_assignment (vlist[i]);
 189
 190               free (vlist);
 191             }
 192         }
 193       else
 194         {
 195           if (flags_on == 0)
 196             set_builtin ((WORD_LIST *)NULL);
 197           else
 198             set_or_show_attributes ((WORD_LIST *)NULL, flags_on, nodefs);
 199         }
 200
 201       fflush (stdout);
 202       return (EXECUTION_SUCCESS);
 203     }
 204
 205   if (pflag)    /* declare -p [-afFirtx] name [name...] */
 206     {
 207       for (any_failed = 0; list; list = list->next)
 208         {
 209           pflag = show_name_attributes (list->word->word, nodefs);
 210           if (pflag)
 211             {
 212               sh_notfound (list->word->word);
 213               any_failed++;
 214             }
 215         }
 216       return (any_failed ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
 217     }
 218
 219 #define NEXT_VARIABLE() free (name); list = list->next; continue
 220
 221   /* There are arguments left, so we are making variables. */
 222   while (list)          /* declare [-afFirx] name [name ...] */
 223     {
 224       char *value, *name;
 225       int offset, aflags;
 226 #if defined (ARRAY_VARS)
 227       int making_array_special, compound_array_assign, simple_array_assign;
 228 #endif
 229
 230       name = savestring (list->word->word);
 231       offset = assignment (name, 0);
 232       aflags = 0;
 233
 234       if (offset)       /* declare [-afFirx] name=value */
 235         {
 236           name[offset] = '\0';
 237           value = name + offset + 1;
 238           if (name[offset - 1] == '+')
 239             {
 240               aflags |= ASS_APPEND;
 241               name[offset - 1] = '\0';
 242             }
 243         }
 244       else
 245         value = "";
 246
 247 #if defined (ARRAY_VARS)
 248       compound_array_assign = simple_array_assign = 0;
 249       subscript_start = (char *)NULL;
 250       if (t = strchr (name, '['))       /* ] */
 251         {
 252           subscript_start = t;
 253           *t = '\0';
 254           making_array_special = 1;
 255         }
 256       else
 257         making_array_special = 0;
 258 #endif
 259
 260       if (legal_identifier (name) == 0)
 261         {
 262           sh_invalidid (name);
 263           assign_error++;
 264           NEXT_VARIABLE ();
 265         }
 266
 267       /* If VARIABLE_CONTEXT has a non-zero value, then we are executing
 268          inside of a function.  This means we should make local variables,
 269          not global ones. */
 270
 271       /* XXX - this has consequences when we're making a local copy of a
 272                variable that was in the temporary environment.  Watch out
 273                for this. */
 274       if (variable_context && ((flags_on & att_function) == 0))
 275         {
 276 #if defined (ARRAY_VARS)
 277           if ((flags_on & att_array) || making_array_special)
 278             var = make_local_array_variable (name);
 279           else
 280 #endif
 281           var = make_local_variable (name);
 282           if (var == 0)
 283             {
 284               any_failed++;
 285               NEXT_VARIABLE ();
 286             }
 287         }
 288       else
 289         var = (SHELL_VAR *)NULL;
 290
 291       /* If we are declaring a function, then complain about it in some way.
 292          We don't let people make functions by saying `typeset -f foo=bar'. */
 293
 294       /* There should be a way, however, to let people look at a particular
 295          function definition by saying `typeset -f foo'. */
 296
 297       if (flags_on & att_function)
 298         {
 299           if (offset)   /* declare -f [-rix] foo=bar */
 300             {
 301               builtin_error (_("cannot use `-f' to make functions"));
 302               free (name);
 303               return (EXECUTION_FAILURE);
 304             }
 305           else          /* declare -f [-rx] name [name...] */
 306             {
 307               var = find_function (name);
 308
 309               if (var)
 310                 {
 311                   if (readonly_p (var) && (flags_off & att_readonly))
 312                     {
 313                       builtin_error (_("%s: readonly function"), name);
 314                       any_failed++;
 315                       NEXT_VARIABLE ();
 316                     }
 317
 318                   /* declare -[Ff] name [name...] */
 319                   if (flags_on == att_function && flags_off == 0)
 320                     {
 321 #if defined (DEBUGGER)
 322                       if (nodefs && debugging_mode)
 323                         {
 324                           shell_fn = find_function_def (var->name);
 325                           if (shell_fn)
 326                             printf ("%s %d %s\n", var->name, shell_fn->line, shell_fn->source_file);
 327                           else
 328                             printf ("%s\n", var->name);
 329                         }
 330                       else
 331 #endif /* DEBUGGER */
 332                         {
 333                           t = nodefs ? var->name
 334                                      : named_function_string (name, function_cell (var), 1);
 335                           printf ("%s\n", t);
 336                         }
 337                     }
 338                   else          /* declare -[fF] -[rx] name [name...] */
 339                     {
 340                       VSETATTR (var, flags_on);
 341                       VUNSETATTR (var, flags_off);
 342                     }
 343                 }
 344               else
 345                 any_failed++;
 346               NEXT_VARIABLE ();
 347             }
 348         }
 349       else              /* declare -[airx] name [name...] */
 350         {
 351           /* Non-null if we just created or fetched a local variable. */
 352           if (var == 0)
 353             var = find_variable (name);
 354
 355           if (var == 0)
 356             {
 357 #if defined (ARRAY_VARS)
 358               if ((flags_on & att_array) || making_array_special)
 359                 var = make_new_array_variable (name);
 360               else
 361 #endif
 362               var = bind_variable (name, "", 0);
 363             }
 364
 365           /* Cannot use declare +r to turn off readonly attribute. */
 366           if (readonly_p (var) && (flags_off & att_readonly))
 367             {
 368               sh_readonly (name);
 369               any_failed++;
 370               NEXT_VARIABLE ();
 371             }
 372
 373           /* Cannot use declare to assign value to readonly or noassign
 374              variable. */
 375           if ((readonly_p (var) || noassign_p (var)) && offset)
 376             {
 377               if (readonly_p (var))
 378                 sh_readonly (name);
 379               assign_error++;
 380               NEXT_VARIABLE ();
 381             }
 382
 383 #if defined (ARRAY_VARS)
 384           if ((making_array_special || (flags_on & att_array) || array_p (var)) && offset)
 385             {
 386               int vlen;
 387               vlen = STRLEN (value);
 388 #if 0
 389               if (value[0] == '(' && strchr (value, ')'))
 390 #else
 391               if (value[0] == '(' && value[vlen-1] == ')')
 392 #endif
 393                 compound_array_assign = 1;
 394               else
 395                 simple_array_assign = 1;
 396             }
 397
 398           /* Cannot use declare +a name to remove an array variable. */
 399           if ((flags_off & att_array) && array_p (var))
 400             {
 401               builtin_error (_("%s: cannot destroy array variables in this way"), name);
 402               any_failed++;
 403               NEXT_VARIABLE ();
 404             }
 405
 406           /* declare -a name makes name an array variable. */
 407           if ((making_array_special || (flags_on & att_array)) && array_p (var) == 0)
 408             var = convert_var_to_array (var);
 409 #endif /* ARRAY_VARS */
 410
 411           VSETATTR (var, flags_on);
 412           VUNSETATTR (var, flags_off);
 413
 414 #if defined (ARRAY_VARS)
 415           if (offset && compound_array_assign)
 416             assign_array_var_from_string (var, value, aflags);
 417           else if (simple_array_assign && subscript_start)
 418             {
 419               /* declare [-a] name[N]=value */
 420               *subscript_start = '[';   /* ] */
 421               var = assign_array_element (name, value, 0);      /* XXX - not aflags */
 422               *subscript_start = '\0';
 423             }
 424           else if (simple_array_assign)
 425             /* let bind_array_variable take care of this. */
 426             bind_array_variable (name, 0, value, aflags);
 427           else
 428 #endif
 429           /* bind_variable_value duplicates the essential internals of
 430              bind_variable() */
 431           if (offset)
 432             bind_variable_value (var, value, aflags);
 433
 434           /* If we found this variable in the temporary environment, as with
 435              `var=value declare -x var', make sure it is treated identically
 436              to `var=value export var'.  Do the same for `declare -r' and
 437              `readonly'.  Preserve the attributes, except for att_tempvar. */
 438           /* XXX -- should this create a variable in the global scope, or
 439              modify the local variable flags?  ksh93 has it modify the
 440              global scope.
 441              Need to handle case like in set_var_attribute where a temporary
 442              variable is in the same table as the function local vars. */
 443           if ((flags_on & (att_exported|att_readonly)) && tempvar_p (var))
 444             {
 445               SHELL_VAR *tv;
 446               char *tvalue;
 447
 448               tv = find_tempenv_variable (var->name);
 449               if (tv)
 450                 {
 451                   tvalue = var_isset (var) ? savestring (value_cell (var)) : savestring ("");
 452                   tv = bind_variable (var->name, tvalue, 0);
 453                   tv->attributes |= var->attributes & ~att_tempvar;
 454                   if (tv->context > 0)
 455                     VSETATTR (tv, att_propagate);
 456                   free (tvalue);
 457                 }
 458               VSETATTR (var, att_propagate);
 459             }
 460         }
 461
 462       stupidly_hack_special_variables (name);
 463
 464       NEXT_VARIABLE ();
 465     }
 466
 467   return (assign_error ? EX_BADASSIGN
 468                        : ((any_failed == 0) ? EXECUTION_SUCCESS
 469                                             : EXECUTION_FAILURE));
 470 }