variables.h

   1 /* variables.h -- data structures for shell variables. */
   2
   3 /* Copyright (C) 1987-2015 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 #if !defined (_VARIABLES_H_)
  22 #define _VARIABLES_H_
  23
  24 #include "stdc.h"
  25 #include "array.h"
  26 #include "assoc.h"
  27
  28 /* Shell variables and functions are stored in hash tables. */
  29 #include "hashlib.h"
  30
  31 #include "conftypes.h"
  32
  33 /* A variable context. */
  34 typedef struct var_context {
  35   char *name;           /* empty or NULL means global context */
  36   int scope;            /* 0 means global context */
  37   int flags;
  38   struct var_context *up;       /* previous function calls */
  39   struct var_context *down;     /* down towards global context */
  40   HASH_TABLE *table;            /* variables at this scope */
  41 } VAR_CONTEXT;
  42
  43 /* Flags for var_context->flags */
  44 #define VC_HASLOCAL     0x01
  45 #define VC_HASTMPVAR    0x02
  46 #define VC_FUNCENV      0x04    /* also function if name != NULL */
  47 #define VC_BLTNENV      0x08    /* builtin_env */
  48 #define VC_TEMPENV      0x10    /* temporary_env */
  49
  50 #define VC_TEMPFLAGS    (VC_FUNCENV|VC_BLTNENV|VC_TEMPENV)
  51
  52 /* Accessing macros */
  53 #define vc_isfuncenv(vc)        (((vc)->flags & VC_FUNCENV) != 0)
  54 #define vc_isbltnenv(vc)        (((vc)->flags & VC_BLTNENV) != 0)
  55 #define vc_istempenv(vc)        (((vc)->flags & (VC_TEMPFLAGS)) == VC_TEMPENV)
  56
  57 #define vc_istempscope(vc)      (((vc)->flags & (VC_TEMPENV|VC_BLTNENV)) != 0)
  58
  59 #define vc_haslocals(vc)        (((vc)->flags & VC_HASLOCAL) != 0)
  60 #define vc_hastmpvars(vc)       (((vc)->flags & VC_HASTMPVAR) != 0)
  61
  62 /* What a shell variable looks like. */
  63
  64 typedef struct variable *sh_var_value_func_t __P((struct variable *));
  65 typedef struct variable *sh_var_assign_func_t __P((struct variable *, char *, arrayind_t, char *));
  66
  67 /* For the future */
  68 union _value {
  69   char *s;                      /* string value */
  70   intmax_t i;                   /* int value */
  71   COMMAND *f;                   /* function */
  72   ARRAY *a;                     /* array */
  73   HASH_TABLE *h;                /* associative array */
  74   double d;                     /* floating point number */
  75 #if defined (HAVE_LONG_DOUBLE)
  76   long double ld;               /* long double */
  77 #endif
  78   struct variable *v;           /* possible indirect variable use */
  79   void *opaque;                 /* opaque data for future use */
  80 };
  81
  82 typedef struct variable {
  83   char *name;                   /* Symbol that the user types. */
  84   char *value;                  /* Value that is returned. */
  85   char *exportstr;              /* String for the environment. */
  86   sh_var_value_func_t *dynamic_value;   /* Function called to return a `dynamic'
  87                                    value for a variable, like $SECONDS
  88                                    or $RANDOM. */
  89   sh_var_assign_func_t *assign_func; /* Function called when this `special
  90                                    variable' is assigned a value in
  91                                    bind_variable. */
  92   int attributes;               /* export, readonly, array, invisible... */
  93   int context;                  /* Which context this variable belongs to. */
  94 } SHELL_VAR;
  95
  96 typedef struct _vlist {
  97   SHELL_VAR **list;
  98   int list_size;        /* allocated size */
  99   int list_len;         /* current number of entries */
 100 } VARLIST;
 101
 102 /* The various attributes that a given variable can have. */
 103 /* First, the user-visible attributes */
 104 #define att_exported    0x0000001       /* export to environment */
 105 #define att_readonly    0x0000002       /* cannot change */
 106 #define att_array       0x0000004       /* value is an array */
 107 #define att_function    0x0000008       /* value is a function */
 108 #define att_integer     0x0000010       /* internal representation is int */
 109 #define att_local       0x0000020       /* variable is local to a function */
 110 #define att_assoc       0x0000040       /* variable is an associative array */
 111 #define att_trace       0x0000080       /* function is traced with DEBUG trap */
 112 #define att_uppercase   0x0000100       /* word converted to uppercase on assignment */
 113 #define att_lowercase   0x0000200       /* word converted to lowercase on assignment */
 114 #define att_capcase     0x0000400       /* word capitalized on assignment */
 115 #define att_nameref     0x0000800       /* word is a name reference */
 116
 117 #define user_attrs      (att_exported|att_readonly|att_integer|att_local|att_trace|att_uppercase|att_lowercase|att_capcase|att_nameref)
 118
 119 #define attmask_user    0x0000fff
 120
 121 /* Internal attributes used for bookkeeping */
 122 #define att_invisible   0x0001000       /* cannot see */
 123 #define att_nounset     0x0002000       /* cannot unset */
 124 #define att_noassign    0x0004000       /* assignment not allowed */
 125 #define att_imported    0x0008000       /* came from environment */
 126 #define att_special     0x0010000       /* requires special handling */
 127 #define att_nofree      0x0020000       /* do not free value on unset */
 128
 129 #define attmask_int     0x00ff000
 130
 131 /* Internal attributes used for variable scoping. */
 132 #define att_tempvar     0x0100000       /* variable came from the temp environment */
 133 #define att_propagate   0x0200000       /* propagate to previous scope */
 134
 135 #define attmask_scope   0x0f00000
 136
 137 #define exported_p(var)         ((((var)->attributes) & (att_exported)))
 138 #define readonly_p(var)         ((((var)->attributes) & (att_readonly)))
 139 #define array_p(var)            ((((var)->attributes) & (att_array)))
 140 #define function_p(var)         ((((var)->attributes) & (att_function)))
 141 #define integer_p(var)          ((((var)->attributes) & (att_integer)))
 142 #define local_p(var)            ((((var)->attributes) & (att_local)))
 143 #define assoc_p(var)            ((((var)->attributes) & (att_assoc)))
 144 #define trace_p(var)            ((((var)->attributes) & (att_trace)))
 145 #define uppercase_p(var)        ((((var)->attributes) & (att_uppercase)))
 146 #define lowercase_p(var)        ((((var)->attributes) & (att_lowercase)))
 147 #define capcase_p(var)          ((((var)->attributes) & (att_capcase)))
 148 #define nameref_p(var)          ((((var)->attributes) & (att_nameref)))
 149
 150 #define invisible_p(var)        ((((var)->attributes) & (att_invisible)))
 151 #define non_unsettable_p(var)   ((((var)->attributes) & (att_nounset)))
 152 #define noassign_p(var)         ((((var)->attributes) & (att_noassign)))
 153 #define imported_p(var)         ((((var)->attributes) & (att_imported)))
 154 #define specialvar_p(var)       ((((var)->attributes) & (att_special)))
 155 #define nofree_p(var)           ((((var)->attributes) & (att_nofree)))
 156
 157 #define tempvar_p(var)          ((((var)->attributes) & (att_tempvar)))
 158
 159 /* Variable names: lvalues */
 160 #define name_cell(var)          ((var)->name)
 161
 162 /* Acessing variable values: rvalues */
 163 #define value_cell(var)         ((var)->value)
 164 #define function_cell(var)      (COMMAND *)((var)->value)
 165 #define array_cell(var)         (ARRAY *)((var)->value)
 166 #define assoc_cell(var)         (HASH_TABLE *)((var)->value)
 167 #define nameref_cell(var)       ((var)->value)          /* so it can change later */
 168
 169 #define NAMEREF_MAX     8       /* only 8 levels of nameref indirection */
 170
 171 #define var_isset(var)          ((var)->value != 0)
 172 #define var_isunset(var)        ((var)->value == 0)
 173 #define var_isnull(var)         ((var)->value && *(var)->value == 0)
 174
 175 /* Assigning variable values: lvalues */
 176 #define var_setvalue(var, str)  ((var)->value = (str))
 177 #define var_setfunc(var, func)  ((var)->value = (char *)(func))
 178 #define var_setarray(var, arr)  ((var)->value = (char *)(arr))
 179 #define var_setassoc(var, arr)  ((var)->value = (char *)(arr))
 180 #define var_setref(var, str)    ((var)->value = (str))
 181
 182 /* Make VAR be auto-exported. */
 183 #define set_auto_export(var) \
 184   do { (var)->attributes |= att_exported; array_needs_making = 1; } while (0)
 185
 186 #define SETVARATTR(var, attr, undo) \
 187         ((undo == 0) ? ((var)->attributes |= (attr)) \
 188                      : ((var)->attributes &= ~(attr)))
 189
 190 #define VSETATTR(var, attr)     ((var)->attributes |= (attr))
 191 #define VUNSETATTR(var, attr)   ((var)->attributes &= ~(attr))
 192
 193 #define VGETFLAGS(var)          ((var)->attributes)
 194
 195 #define VSETFLAGS(var, flags)   ((var)->attributes = (flags))
 196 #define VCLRFLAGS(var)          ((var)->attributes = 0)
 197
 198 /* Macros to perform various operations on `exportstr' member of a SHELL_VAR. */
 199 #define CLEAR_EXPORTSTR(var)    (var)->exportstr = (char *)NULL
 200 #define COPY_EXPORTSTR(var)     ((var)->exportstr) ? savestring ((var)->exportstr) : (char *)NULL
 201 #define SET_EXPORTSTR(var, value)  (var)->exportstr = (value)
 202 #define SAVE_EXPORTSTR(var, value) (var)->exportstr = (value) ? savestring (value) : (char *)NULL
 203
 204 #define FREE_EXPORTSTR(var) \
 205         do { if ((var)->exportstr) free ((var)->exportstr); } while (0)
 206
 207 #define CACHE_IMPORTSTR(var, value) \
 208         (var)->exportstr = savestring (value)
 209
 210 #define INVALIDATE_EXPORTSTR(var) \
 211         do { \
 212           if ((var)->exportstr) \
 213             { \
 214               free ((var)->exportstr); \
 215               (var)->exportstr = (char *)NULL; \
 216             } \
 217         } while (0)
 218
 219 #define ifsname(s)      ((s)[0] == 'I' && (s)[1] == 'F' && (s)[2] == 'S' && (s)[3] == '\0')
 220
 221 /* Special value for nameref with invalid value for creation or assignment */
 222 extern SHELL_VAR nameref_invalid_value;
 223 #define INVALID_NAMEREF_VALUE   (void *)&nameref_invalid_value
 224
 225 /* Stuff for hacking variables. */
 226 typedef int sh_var_map_func_t __P((SHELL_VAR *));
 227
 228 /* Where we keep the variables and functions */
 229 extern VAR_CONTEXT *global_variables;
 230 extern VAR_CONTEXT *shell_variables;
 231
 232 extern HASH_TABLE *shell_functions;
 233 extern HASH_TABLE *temporary_env;
 234
 235 extern int variable_context;
 236 extern char *dollar_vars[];
 237 extern char **export_env;
 238
 239 extern void initialize_shell_variables __P((char **, int));
 240 extern SHELL_VAR *set_if_not __P((char *, char *));
 241
 242 extern void sh_set_lines_and_columns __P((int, int));
 243 extern void set_pwd __P((void));
 244 extern void set_ppid __P((void));
 245 extern void make_funcname_visible __P((int));
 246
 247 extern SHELL_VAR *var_lookup __P((const char *, VAR_CONTEXT *));
 248
 249 extern SHELL_VAR *find_function __P((const char *));
 250 extern FUNCTION_DEF *find_function_def __P((const char *));
 251 extern SHELL_VAR *find_variable __P((const char *));
 252 extern SHELL_VAR *find_variable_noref __P((const char *));
 253 extern SHELL_VAR *find_variable_last_nameref __P((const char *, int));
 254 extern SHELL_VAR *find_global_variable_last_nameref __P((const char *, int));
 255 extern SHELL_VAR *find_variable_nameref __P((SHELL_VAR *));
 256 extern SHELL_VAR *find_variable_nameref_for_create __P((const char *, int));
 257 extern SHELL_VAR *find_variable_nameref_for_assignment __P((const char *, int));
 258 /*extern SHELL_VAR *find_variable_internal __P((const char *, int));*/
 259 extern SHELL_VAR *find_variable_tempenv __P((const char *));
 260 extern SHELL_VAR *find_variable_notempenv __P((const char *));
 261 extern SHELL_VAR *find_global_variable __P((const char *));
 262 extern SHELL_VAR *find_global_variable_noref __P((const char *));
 263 extern SHELL_VAR *find_shell_variable __P((const char *));
 264 extern SHELL_VAR *find_tempenv_variable __P((const char *));
 265 extern SHELL_VAR *find_variable_no_invisible __P((const char *));
 266 extern SHELL_VAR *find_variable_for_assignment __P((const char *));
 267 extern SHELL_VAR *copy_variable __P((SHELL_VAR *));
 268 extern SHELL_VAR *make_local_variable __P((const char *));
 269 extern SHELL_VAR *bind_variable __P((const char *, char *, int));
 270 extern SHELL_VAR *bind_global_variable __P((const char *, char *, int));
 271 extern SHELL_VAR *bind_function __P((const char *, COMMAND *));
 272
 273 extern void bind_function_def __P((const char *, FUNCTION_DEF *));
 274
 275 extern SHELL_VAR **map_over __P((sh_var_map_func_t *, VAR_CONTEXT *));
 276 SHELL_VAR **map_over_funcs __P((sh_var_map_func_t *));
 277
 278 extern SHELL_VAR **all_shell_variables __P((void));
 279 extern SHELL_VAR **all_shell_functions __P((void));
 280 extern SHELL_VAR **all_visible_variables __P((void));
 281 extern SHELL_VAR **all_visible_functions __P((void));
 282 extern SHELL_VAR **all_exported_variables __P((void));
 283 extern SHELL_VAR **local_exported_variables __P((void));
 284 extern SHELL_VAR **all_local_variables __P((void));
 285 #if defined (ARRAY_VARS)
 286 extern SHELL_VAR **all_array_variables __P((void));
 287 #endif
 288 extern char **all_variables_matching_prefix __P((const char *));
 289
 290 extern char **make_var_array __P((HASH_TABLE *));
 291 extern char **add_or_supercede_exported_var __P((char *, int));
 292
 293 extern char *get_variable_value __P((SHELL_VAR *));
 294 extern char *get_string_value __P((const char *));
 295 extern char *sh_get_env_value __P((const char *));
 296 extern char *make_variable_value __P((SHELL_VAR *, char *, int));
 297
 298 extern SHELL_VAR *bind_variable_value __P((SHELL_VAR *, char *, int));
 299 extern SHELL_VAR *bind_int_variable __P((char *, char *));
 300 extern SHELL_VAR *bind_var_to_int __P((char *, intmax_t));
 301
 302 extern int assign_in_env __P((WORD_DESC *, int));
 303
 304 extern int unbind_variable __P((const char *));
 305 extern int check_unbind_variable __P((const char *));
 306 extern int unbind_nameref __P((const char *));
 307 extern int unbind_variable_noref __P((const char *));
 308 extern int unbind_func __P((const char *));
 309 extern int unbind_function_def __P((const char *));
 310 extern int delete_var __P((const char *, VAR_CONTEXT *));
 311 extern int makunbound __P((const char *, VAR_CONTEXT *));
 312 extern int kill_local_variable __P((const char *));
 313 extern void delete_all_variables __P((HASH_TABLE *));
 314 extern void delete_all_contexts __P((VAR_CONTEXT *));
 315
 316 extern VAR_CONTEXT *new_var_context __P((char *, int));
 317 extern void dispose_var_context __P((VAR_CONTEXT *));
 318 extern VAR_CONTEXT *push_var_context __P((char *, int, HASH_TABLE *));
 319 extern void pop_var_context __P((void));
 320 extern VAR_CONTEXT *push_scope __P((int, HASH_TABLE *));
 321 extern void pop_scope __P((int));
 322
 323 extern void push_context __P((char *, int, HASH_TABLE *));
 324 extern void pop_context __P((void));
 325 extern void push_dollar_vars __P((void));
 326 extern void pop_dollar_vars __P((void));
 327 extern void dispose_saved_dollar_vars __P((void));
 328
 329 extern void push_args __P((WORD_LIST *));
 330 extern void pop_args __P((void));
 331
 332 extern void adjust_shell_level __P((int));
 333 extern void non_unsettable __P((char *));
 334 extern void dispose_variable __P((SHELL_VAR *));
 335 extern void dispose_used_env_vars __P((void));
 336 extern void dispose_function_env __P((void));
 337 extern void dispose_builtin_env __P((void));
 338 extern void merge_temporary_env __P((void));
 339 extern void flush_temporary_env __P((void));
 340 extern void merge_builtin_env __P((void));
 341 extern void kill_all_local_variables __P((void));
 342
 343 extern void set_var_read_only __P((char *));
 344 extern void set_func_read_only __P((const char *));
 345 extern void set_var_auto_export __P((char *));
 346 extern void set_func_auto_export __P((const char *));
 347
 348 extern void sort_variables __P((SHELL_VAR **));
 349
 350 extern int chkexport __P((char *));
 351 extern void maybe_make_export_env __P((void));
 352 extern void update_export_env_inplace __P((char *, int, char *));
 353 extern void put_command_name_into_env __P((char *));
 354 extern void put_gnu_argv_flags_into_env __P((intmax_t, char *));
 355
 356 extern void print_var_list __P((SHELL_VAR **));
 357 extern void print_func_list __P((SHELL_VAR **));
 358 extern void print_assignment __P((SHELL_VAR *));
 359 extern void print_var_value __P((SHELL_VAR *, int));
 360 extern void print_var_function __P((SHELL_VAR *));
 361
 362 #if defined (ARRAY_VARS)
 363 extern SHELL_VAR *make_new_array_variable __P((char *));
 364 extern SHELL_VAR *make_local_array_variable __P((char *, int));
 365
 366 extern SHELL_VAR *make_new_assoc_variable __P((char *));
 367 extern SHELL_VAR *make_local_assoc_variable __P((char *));
 368
 369 extern void set_pipestatus_array __P((int *, int));
 370 extern ARRAY *save_pipestatus_array __P((void));
 371 extern void restore_pipestatus_array __P((ARRAY *));
 372 #endif
 373
 374 extern void set_pipestatus_from_exit __P((int));
 375
 376 /* The variable in NAME has just had its state changed.  Check to see if it
 377    is one of the special ones where something special happens. */
 378 extern void stupidly_hack_special_variables __P((char *));
 379
 380 /* Reinitialize some special variables that have external effects upon unset
 381    when the shell reinitializes itself. */
 382 extern void reinit_special_variables __P((void));
 383
 384 extern int get_random_number __P((void));
 385
 386 /* The `special variable' functions that get called when a particular
 387    variable is set. */
 388 extern void sv_ifs __P((char *));
 389 extern void sv_path __P((char *));
 390 extern void sv_mail __P((char *));
 391 extern void sv_funcnest __P((char *));
 392 extern void sv_execignore __P((char *));
 393 extern void sv_globignore __P((char *));
 394 extern void sv_ignoreeof __P((char *));
 395 extern void sv_strict_posix __P((char *));
 396 extern void sv_optind __P((char *));
 397 extern void sv_opterr __P((char *));
 398 extern void sv_locale __P((char *));
 399 extern void sv_xtracefd __P((char *));
 400 extern void sv_shcompat __P((char *));
 401
 402 #if defined (READLINE)
 403 extern void sv_comp_wordbreaks __P((char *));
 404 extern void sv_terminal __P((char *));
 405 extern void sv_hostfile __P((char *));
 406 extern void sv_winsize __P((char *));
 407 #endif
 408
 409 #if defined (__CYGWIN__)
 410 extern void sv_home __P((char *));
 411 #endif
 412
 413 #if defined (HISTORY)
 414 extern void sv_histsize __P((char *));
 415 extern void sv_histignore __P((char *));
 416 extern void sv_history_control __P((char *));
 417 #  if defined (BANG_HISTORY)
 418 extern void sv_histchars __P((char *));
 419 #  endif
 420 extern void sv_histtimefmt __P((char *));
 421 #endif /* HISTORY */
 422
 423 #if defined (HAVE_TZSET)
 424 extern void sv_tz __P((char *));
 425 #endif
 426
 427 #if defined (JOB_CONTROL)
 428 extern void sv_childmax __P((char *));
 429 #endif
 430
 431 #endif /* !_VARIABLES_H_ */