variables.h

   1 /* variables.h -- data structures for shell variables. */
   2
   3 /* Copyright (C) 1987-2020 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 PARAMS((struct variable *));
  65 typedef struct variable *sh_var_assign_func_t PARAMS((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 #define att_regenerate  0x0040000       /* regenerate when exported */
 129
 130 #define attmask_int     0x00ff000
 131
 132 /* Internal attributes used for variable scoping. */
 133 #define att_tempvar     0x0100000       /* variable came from the temp environment */
 134 #define att_propagate   0x0200000       /* propagate to previous scope */
 135
 136 #define attmask_scope   0x0f00000
 137
 138 #define exported_p(var)         ((((var)->attributes) & (att_exported)))
 139 #define readonly_p(var)         ((((var)->attributes) & (att_readonly)))
 140 #define array_p(var)            ((((var)->attributes) & (att_array)))
 141 #define function_p(var)         ((((var)->attributes) & (att_function)))
 142 #define integer_p(var)          ((((var)->attributes) & (att_integer)))
 143 #define local_p(var)            ((((var)->attributes) & (att_local)))
 144 #define assoc_p(var)            ((((var)->attributes) & (att_assoc)))
 145 #define trace_p(var)            ((((var)->attributes) & (att_trace)))
 146 #define uppercase_p(var)        ((((var)->attributes) & (att_uppercase)))
 147 #define lowercase_p(var)        ((((var)->attributes) & (att_lowercase)))
 148 #define capcase_p(var)          ((((var)->attributes) & (att_capcase)))
 149 #define nameref_p(var)          ((((var)->attributes) & (att_nameref)))
 150
 151 #define invisible_p(var)        ((((var)->attributes) & (att_invisible)))
 152 #define non_unsettable_p(var)   ((((var)->attributes) & (att_nounset)))
 153 #define noassign_p(var)         ((((var)->attributes) & (att_noassign)))
 154 #define imported_p(var)         ((((var)->attributes) & (att_imported)))
 155 #define specialvar_p(var)       ((((var)->attributes) & (att_special)))
 156 #define nofree_p(var)           ((((var)->attributes) & (att_nofree)))
 157 #define regen_p(var)            ((((var)->attributes) & (att_regenerate)))
 158
 159 #define tempvar_p(var)          ((((var)->attributes) & (att_tempvar)))
 160 #define propagate_p(var)        ((((var)->attributes) & (att_propagate)))
 161
 162 /* Variable names: lvalues */
 163 #define name_cell(var)          ((var)->name)
 164
 165 /* Accessing variable values: rvalues */
 166 #define value_cell(var)         ((var)->value)
 167 #define function_cell(var)      (COMMAND *)((var)->value)
 168 #define array_cell(var)         (ARRAY *)((var)->value)
 169 #define assoc_cell(var)         (HASH_TABLE *)((var)->value)
 170 #define nameref_cell(var)       ((var)->value)          /* so it can change later */
 171
 172 #define NAMEREF_MAX     8       /* only 8 levels of nameref indirection */
 173
 174 #define var_isset(var)          ((var)->value != 0)
 175 #define var_isunset(var)        ((var)->value == 0)
 176 #define var_isnull(var)         ((var)->value && *(var)->value == 0)
 177
 178 /* Assigning variable values: lvalues */
 179 #define var_setvalue(var, str)  ((var)->value = (str))
 180 #define var_setfunc(var, func)  ((var)->value = (char *)(func))
 181 #define var_setarray(var, arr)  ((var)->value = (char *)(arr))
 182 #define var_setassoc(var, arr)  ((var)->value = (char *)(arr))
 183 #define var_setref(var, str)    ((var)->value = (str))
 184
 185 /* Make VAR be auto-exported. */
 186 #define set_auto_export(var) \
 187   do { (var)->attributes |= att_exported; array_needs_making = 1; } while (0)
 188
 189 #define SETVARATTR(var, attr, undo) \
 190         ((undo == 0) ? ((var)->attributes |= (attr)) \
 191                      : ((var)->attributes &= ~(attr)))
 192
 193 #define VSETATTR(var, attr)     ((var)->attributes |= (attr))
 194 #define VUNSETATTR(var, attr)   ((var)->attributes &= ~(attr))
 195
 196 #define VGETFLAGS(var)          ((var)->attributes)
 197
 198 #define VSETFLAGS(var, flags)   ((var)->attributes = (flags))
 199 #define VCLRFLAGS(var)          ((var)->attributes = 0)
 200
 201 /* Macros to perform various operations on `exportstr' member of a SHELL_VAR. */
 202 #define CLEAR_EXPORTSTR(var)    (var)->exportstr = (char *)NULL
 203 #define COPY_EXPORTSTR(var)     ((var)->exportstr) ? savestring ((var)->exportstr) : (char *)NULL
 204 #define SET_EXPORTSTR(var, value)  (var)->exportstr = (value)
 205 #define SAVE_EXPORTSTR(var, value) (var)->exportstr = (value) ? savestring (value) : (char *)NULL
 206
 207 #define FREE_EXPORTSTR(var) \
 208         do { if ((var)->exportstr) free ((var)->exportstr); } while (0)
 209
 210 #define CACHE_IMPORTSTR(var, value) \
 211         (var)->exportstr = savestring (value)
 212
 213 #define INVALIDATE_EXPORTSTR(var) \
 214         do { \
 215           if ((var)->exportstr) \
 216             { \
 217               free ((var)->exportstr); \
 218               (var)->exportstr = (char *)NULL; \
 219             } \
 220         } while (0)
 221
 222 #define ifsname(s)      ((s)[0] == 'I' && (s)[1] == 'F' && (s)[2] == 'S' && (s)[3] == '\0')
 223
 224 /* Flag values for make_local_variable and its array counterparts */
 225 #define MKLOC_ASSOCOK           0x01
 226 #define MKLOC_ARRAYOK           0x02
 227 #define MKLOC_INHERIT           0x04
 228
 229 /* Special value for nameref with invalid value for creation or assignment */
 230 extern SHELL_VAR nameref_invalid_value;
 231 #define INVALID_NAMEREF_VALUE   (void *)&nameref_invalid_value
 232
 233 /* Stuff for hacking variables. */
 234 typedef int sh_var_map_func_t PARAMS((SHELL_VAR *));
 235
 236 /* Where we keep the variables and functions */
 237 extern VAR_CONTEXT *global_variables;
 238 extern VAR_CONTEXT *shell_variables;
 239
 240 extern HASH_TABLE *shell_functions;
 241 extern HASH_TABLE *temporary_env;
 242
 243 extern int variable_context;
 244 extern char *dollar_vars[];
 245 extern char **export_env;
 246
 247 extern int tempenv_assign_error;
 248 extern int array_needs_making;
 249 extern int shell_level;
 250
 251 /* XXX */
 252 extern WORD_LIST *rest_of_args;
 253 extern int posparam_count;
 254 extern pid_t dollar_dollar_pid;
 255
 256 extern int localvar_inherit;            /* declared in variables.c */
 257
 258 extern void initialize_shell_variables PARAMS((char **, int));
 259
 260 extern int validate_inherited_value PARAMS((SHELL_VAR *, int));
 261
 262 extern SHELL_VAR *set_if_not PARAMS((char *, char *));
 263
 264 extern void sh_set_lines_and_columns PARAMS((int, int));
 265 extern void set_pwd PARAMS((void));
 266 extern void set_ppid PARAMS((void));
 267 extern void make_funcname_visible PARAMS((int));
 268
 269 extern SHELL_VAR *var_lookup PARAMS((const char *, VAR_CONTEXT *));
 270
 271 extern SHELL_VAR *find_function PARAMS((const char *));
 272 extern FUNCTION_DEF *find_function_def PARAMS((const char *));
 273 extern SHELL_VAR *find_variable PARAMS((const char *));
 274 extern SHELL_VAR *find_variable_noref PARAMS((const char *));
 275 extern SHELL_VAR *find_variable_last_nameref PARAMS((const char *, int));
 276 extern SHELL_VAR *find_global_variable_last_nameref PARAMS((const char *, int));
 277 extern SHELL_VAR *find_variable_nameref PARAMS((SHELL_VAR *));
 278 extern SHELL_VAR *find_variable_nameref_for_create PARAMS((const char *, int));
 279 extern SHELL_VAR *find_variable_nameref_for_assignment PARAMS((const char *, int));
 280 /*extern SHELL_VAR *find_variable_internal PARAMS((const char *, int));*/
 281 extern SHELL_VAR *find_variable_tempenv PARAMS((const char *));
 282 extern SHELL_VAR *find_variable_notempenv PARAMS((const char *));
 283 extern SHELL_VAR *find_global_variable PARAMS((const char *));
 284 extern SHELL_VAR *find_global_variable_noref PARAMS((const char *));
 285 extern SHELL_VAR *find_shell_variable PARAMS((const char *));
 286 extern SHELL_VAR *find_tempenv_variable PARAMS((const char *));
 287 extern SHELL_VAR *find_variable_no_invisible PARAMS((const char *));
 288 extern SHELL_VAR *find_variable_for_assignment PARAMS((const char *));
 289 extern char *nameref_transform_name PARAMS((char *, int));
 290 extern SHELL_VAR *copy_variable PARAMS((SHELL_VAR *));
 291 extern SHELL_VAR *make_local_variable PARAMS((const char *, int));
 292 extern SHELL_VAR *bind_variable PARAMS((const char *, char *, int));
 293 extern SHELL_VAR *bind_global_variable PARAMS((const char *, char *, int));
 294 extern SHELL_VAR *bind_function PARAMS((const char *, COMMAND *));
 295
 296 extern void bind_function_def PARAMS((const char *, FUNCTION_DEF *, int));
 297
 298 extern SHELL_VAR **map_over PARAMS((sh_var_map_func_t *, VAR_CONTEXT *));
 299 SHELL_VAR **map_over_funcs PARAMS((sh_var_map_func_t *));
 300
 301 extern SHELL_VAR **all_shell_variables PARAMS((void));
 302 extern SHELL_VAR **all_shell_functions PARAMS((void));
 303 extern SHELL_VAR **all_visible_variables PARAMS((void));
 304 extern SHELL_VAR **all_visible_functions PARAMS((void));
 305 extern SHELL_VAR **all_exported_variables PARAMS((void));
 306 extern SHELL_VAR **local_exported_variables PARAMS((void));
 307 extern SHELL_VAR **all_local_variables PARAMS((int));
 308 #if defined (ARRAY_VARS)
 309 extern SHELL_VAR **all_array_variables PARAMS((void));
 310 #endif
 311 extern char **all_variables_matching_prefix PARAMS((const char *));
 312
 313 extern char **make_var_array PARAMS((HASH_TABLE *));
 314 extern char **add_or_supercede_exported_var PARAMS((char *, int));
 315
 316 extern char *get_variable_value PARAMS((SHELL_VAR *));
 317 extern char *get_string_value PARAMS((const char *));
 318 extern char *sh_get_env_value PARAMS((const char *));
 319 extern char *make_variable_value PARAMS((SHELL_VAR *, char *, int));
 320
 321 extern SHELL_VAR *bind_variable_value PARAMS((SHELL_VAR *, char *, int));
 322 extern SHELL_VAR *bind_int_variable PARAMS((char *, char *, int));
 323 extern SHELL_VAR *bind_var_to_int PARAMS((char *, intmax_t));
 324
 325 extern int assign_in_env PARAMS((WORD_DESC *, int));
 326
 327 extern int unbind_variable PARAMS((const char *));
 328 extern int check_unbind_variable PARAMS((const char *));
 329 extern int unbind_nameref PARAMS((const char *));
 330 extern int unbind_variable_noref PARAMS((const char *));
 331 extern int unbind_func PARAMS((const char *));
 332 extern int unbind_function_def PARAMS((const char *));
 333 extern int delete_var PARAMS((const char *, VAR_CONTEXT *));
 334 extern int makunbound PARAMS((const char *, VAR_CONTEXT *));
 335 extern int kill_local_variable PARAMS((const char *));
 336 extern void delete_all_variables PARAMS((HASH_TABLE *));
 337 extern void delete_all_contexts PARAMS((VAR_CONTEXT *));
 338
 339 extern VAR_CONTEXT *new_var_context PARAMS((char *, int));
 340 extern void dispose_var_context PARAMS((VAR_CONTEXT *));
 341 extern VAR_CONTEXT *push_var_context PARAMS((char *, int, HASH_TABLE *));
 342 extern void pop_var_context PARAMS((void));
 343 extern VAR_CONTEXT *push_scope PARAMS((int, HASH_TABLE *));
 344 extern void pop_scope PARAMS((int));
 345
 346 extern void clear_dollar_vars PARAMS((void));
 347
 348 extern void push_context PARAMS((char *, int, HASH_TABLE *));
 349 extern void pop_context PARAMS((void));
 350 extern void push_dollar_vars PARAMS((void));
 351 extern void pop_dollar_vars PARAMS((void));
 352 extern void dispose_saved_dollar_vars PARAMS((void));
 353
 354 extern void init_bash_argv PARAMS((void));
 355 extern void save_bash_argv PARAMS((void));
 356 extern void push_args PARAMS((WORD_LIST *));
 357 extern void pop_args PARAMS((void));
 358
 359 extern void adjust_shell_level PARAMS((int));
 360 extern void non_unsettable PARAMS((char *));
 361 extern void dispose_variable PARAMS((SHELL_VAR *));
 362 extern void dispose_used_env_vars PARAMS((void));
 363 extern void dispose_function_env PARAMS((void));
 364 extern void dispose_builtin_env PARAMS((void));
 365 extern void merge_temporary_env PARAMS((void));
 366 extern void flush_temporary_env PARAMS((void));
 367 extern void merge_builtin_env PARAMS((void));
 368 extern void kill_all_local_variables PARAMS((void));
 369
 370 extern void set_var_read_only PARAMS((char *));
 371 extern void set_func_read_only PARAMS((const char *));
 372 extern void set_var_auto_export PARAMS((char *));
 373 extern void set_func_auto_export PARAMS((const char *));
 374
 375 extern void sort_variables PARAMS((SHELL_VAR **));
 376
 377 extern int chkexport PARAMS((char *));
 378 extern void maybe_make_export_env PARAMS((void));
 379 extern void update_export_env_inplace PARAMS((char *, int, char *));
 380 extern void put_command_name_into_env PARAMS((char *));
 381 extern void put_gnu_argv_flags_into_env PARAMS((intmax_t, char *));
 382
 383 extern void print_var_list PARAMS((SHELL_VAR **));
 384 extern void print_func_list PARAMS((SHELL_VAR **));
 385 extern void print_assignment PARAMS((SHELL_VAR *));
 386 extern void print_var_value PARAMS((SHELL_VAR *, int));
 387 extern void print_var_function PARAMS((SHELL_VAR *));
 388
 389 #if defined (ARRAY_VARS)
 390 extern SHELL_VAR *make_new_array_variable PARAMS((char *));
 391 extern SHELL_VAR *make_local_array_variable PARAMS((char *, int));
 392
 393 extern SHELL_VAR *make_new_assoc_variable PARAMS((char *));
 394 extern SHELL_VAR *make_local_assoc_variable PARAMS((char *, int));
 395
 396 extern void set_pipestatus_array PARAMS((int *, int));
 397 extern ARRAY *save_pipestatus_array PARAMS((void));
 398 extern void restore_pipestatus_array PARAMS((ARRAY *));
 399 #endif
 400
 401 extern void set_pipestatus_from_exit PARAMS((int));
 402
 403 /* The variable in NAME has just had its state changed.  Check to see if it
 404    is one of the special ones where something special happens. */
 405 extern void stupidly_hack_special_variables PARAMS((char *));
 406
 407 /* Reinitialize some special variables that have external effects upon unset
 408    when the shell reinitializes itself. */
 409 extern void reinit_special_variables PARAMS((void));
 410
 411 extern int get_random_number PARAMS((void));
 412
 413 /* The `special variable' functions that get called when a particular
 414    variable is set. */
 415 extern void sv_ifs PARAMS((char *));
 416 extern void sv_path PARAMS((char *));
 417 extern void sv_mail PARAMS((char *));
 418 extern void sv_funcnest PARAMS((char *));
 419 extern void sv_execignore PARAMS((char *));
 420 extern void sv_globignore PARAMS((char *));
 421 extern void sv_ignoreeof PARAMS((char *));
 422 extern void sv_strict_posix PARAMS((char *));
 423 extern void sv_optind PARAMS((char *));
 424 extern void sv_opterr PARAMS((char *));
 425 extern void sv_locale PARAMS((char *));
 426 extern void sv_xtracefd PARAMS((char *));
 427 extern void sv_shcompat PARAMS((char *));
 428
 429 #if defined (READLINE)
 430 extern void sv_comp_wordbreaks PARAMS((char *));
 431 extern void sv_terminal PARAMS((char *));
 432 extern void sv_hostfile PARAMS((char *));
 433 extern void sv_winsize PARAMS((char *));
 434 #endif
 435
 436 #if defined (__CYGWIN__)
 437 extern void sv_home PARAMS((char *));
 438 #endif
 439
 440 #if defined (HISTORY)
 441 extern void sv_histsize PARAMS((char *));
 442 extern void sv_histignore PARAMS((char *));
 443 extern void sv_history_control PARAMS((char *));
 444 #  if defined (BANG_HISTORY)
 445 extern void sv_histchars PARAMS((char *));
 446 #  endif
 447 extern void sv_histtimefmt PARAMS((char *));
 448 #endif /* HISTORY */
 449
 450 #if defined (HAVE_TZSET)
 451 extern void sv_tz PARAMS((char *));
 452 #endif
 453
 454 #if defined (JOB_CONTROL)
 455 extern void sv_childmax PARAMS((char *));
 456 #endif
 457
 458 #endif /* !_VARIABLES_H_ */