subst.h

   1 /* subst.h -- Names of externally visible functions in subst.c. */
   2
   3 /* Copyright (C) 1993-2021 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 (_SUBST_H_)
  22 #define _SUBST_H_
  23
  24 #include "stdc.h"
  25
  26 /* Constants which specify how to handle backslashes and quoting in
  27    expand_word_internal ().  Q_DOUBLE_QUOTES means to use the function
  28    slashify_in_quotes () to decide whether the backslash should be
  29    retained.  Q_HERE_DOCUMENT means slashify_in_here_document () to
  30    decide whether to retain the backslash.  Q_KEEP_BACKSLASH means
  31    to unconditionally retain the backslash.  Q_PATQUOTE means that we're
  32    expanding a pattern ${var%#[#%]pattern} in an expansion surrounded
  33    by double quotes. Q_DOLBRACE means we are expanding a ${...} word, so
  34    backslashes should also escape { and } and be removed. */
  35 #define Q_DOUBLE_QUOTES  0x001
  36 #define Q_HERE_DOCUMENT  0x002
  37 #define Q_KEEP_BACKSLASH 0x004
  38 #define Q_PATQUOTE       0x008
  39 #define Q_QUOTED         0x010
  40 #define Q_ADDEDQUOTES    0x020
  41 #define Q_QUOTEDNULL     0x040
  42 #define Q_DOLBRACE       0x080
  43 #define Q_ARITH          0x100  /* expanding string for arithmetic evaluation */
  44 #define Q_ARRAYSUB       0x200  /* expanding indexed array subscript */
  45
  46 /* Flag values controlling how assignment statements are treated. */
  47 #define ASS_APPEND      0x0001
  48 #define ASS_MKLOCAL     0x0002
  49 #define ASS_MKASSOC     0x0004
  50 #define ASS_MKGLOBAL    0x0008  /* force global assignment */
  51 #define ASS_NAMEREF     0x0010  /* assigning to nameref variable */
  52 #define ASS_FORCE       0x0020  /* force assignment even to readonly variable */
  53 #define ASS_CHKLOCAL    0x0040  /* check local variable before assignment */
  54 #define ASS_NOEXPAND    0x0080  /* don't expand associative array subscripts */
  55 #define ASS_NOEVAL      0x0100  /* don't evaluate value as expression */
  56 #define ASS_NOLONGJMP   0x0200  /* don't longjmp on fatal assignment error */
  57 #define ASS_NOINVIS     0x0400  /* don't resolve local invisible variables */
  58 #define ASS_ALLOWALLSUB 0x0800  /* allow * and @ as associative array keys */
  59 #define ASS_ONEWORD     0x1000  /* don't check array subscripts, assume higher level has done that */
  60
  61 /* Flags for the string extraction functions. */
  62 #define SX_NOALLOC      0x0001  /* just skip; don't return substring */
  63 #define SX_VARNAME      0x0002  /* variable name; for string_extract () */
  64 #define SX_REQMATCH     0x0004  /* closing/matching delimiter required */
  65 #define SX_COMMAND      0x0008  /* extracting a shell script/command */
  66 #define SX_NOCTLESC     0x0010  /* don't honor CTLESC quoting */
  67 #define SX_NOESCCTLNUL  0x0020  /* don't let CTLESC quote CTLNUL */
  68 #define SX_NOLONGJMP    0x0040  /* don't longjmp on fatal error */
  69 #define SX_ARITHSUB     0x0080  /* extracting $(( ... )) (currently unused) */
  70 #define SX_POSIXEXP     0x0100  /* extracting new Posix pattern removal expansions in extract_dollar_brace_string */
  71 #define SX_WORD         0x0200  /* extracting word in ${param op word} */
  72 #define SX_COMPLETE     0x0400  /* extracting word for completion */
  73 #define SX_STRIPDQ      0x0800  /* strip double quotes when extracting double-quoted string */
  74 #define SX_NOERROR      0x1000  /* don't print parser error messages */
  75
  76 /* Remove backslashes which are quoting backquotes from STRING.  Modifies
  77    STRING, and returns a pointer to it. */
  78 extern char * de_backslash PARAMS((char *));
  79
  80 /* Replace instances of \! in a string with !. */
  81 extern void unquote_bang PARAMS((char *));
  82
  83 /* Extract the $( construct in STRING, and return a new string.
  84    Start extracting at (SINDEX) as if we had just seen "$(".
  85    Make (SINDEX) get the position just after the matching ")".
  86    XFLAGS is additional flags to pass to other extraction functions, */
  87 extern char *extract_command_subst PARAMS((char *, int *, int));
  88
  89 /* Extract the $[ construct in STRING, and return a new string.
  90    Start extracting at (SINDEX) as if we had just seen "$[".
  91    Make (SINDEX) get the position just after the matching "]". */
  92 extern char *extract_arithmetic_subst PARAMS((char *, int *));
  93
  94 #if defined (PROCESS_SUBSTITUTION)
  95 /* Extract the <( or >( construct in STRING, and return a new string.
  96    Start extracting at (SINDEX) as if we had just seen "<(".
  97    Make (SINDEX) get the position just after the matching ")". */
  98 extern char *extract_process_subst PARAMS((char *, char *, int *, int));
  99 #endif /* PROCESS_SUBSTITUTION */
 100
 101 /* Extract the name of the variable to bind to from the assignment string. */
 102 extern char *assignment_name PARAMS((char *));
 103
 104 /* Return a single string of all the words present in LIST, separating
 105    each word with SEP. */
 106 extern char *string_list_internal PARAMS((WORD_LIST *, char *));
 107
 108 /* Return a single string of all the words present in LIST, separating
 109    each word with a space. */
 110 extern char *string_list PARAMS((WORD_LIST *));
 111
 112 /* Turn $* into a single string, obeying POSIX rules. */
 113 extern char *string_list_dollar_star PARAMS((WORD_LIST *, int, int));
 114
 115 /* Expand $@ into a single string, obeying POSIX rules. */
 116 extern char *string_list_dollar_at PARAMS((WORD_LIST *, int, int));
 117
 118 /* Turn the positional parameters into a string, understanding quoting and
 119    the various subtleties of using the first character of $IFS as the
 120    separator.  Calls string_list_dollar_at, string_list_dollar_star, and
 121    string_list as appropriate. */
 122 extern char *string_list_pos_params PARAMS((int, WORD_LIST *, int, int));
 123
 124 /* Perform quoted null character removal on each element of LIST.
 125    This modifies LIST. */
 126 extern void word_list_remove_quoted_nulls PARAMS((WORD_LIST *));
 127
 128 /* This performs word splitting and quoted null character removal on
 129    STRING. */
 130 extern WORD_LIST *list_string PARAMS((char *, char *, int));
 131
 132 extern char *ifs_firstchar  PARAMS((int *));
 133 extern char *get_word_from_string PARAMS((char **, char *, char **));
 134 extern char *strip_trailing_ifs_whitespace PARAMS((char *, char *, int));
 135
 136 /* Given STRING, an assignment string, get the value of the right side
 137    of the `=', and bind it to the left side.  If EXPAND is true, then
 138    perform tilde expansion, parameter expansion, command substitution,
 139    and arithmetic expansion on the right-hand side.  Do not perform word
 140    splitting on the result of expansion. */
 141 extern int do_assignment PARAMS((char *));
 142 extern int do_assignment_no_expand PARAMS((char *));
 143 extern int do_word_assignment PARAMS((WORD_DESC *, int));
 144
 145 /* Append SOURCE to TARGET at INDEX.  SIZE is the current amount
 146    of space allocated to TARGET.  SOURCE can be NULL, in which
 147    case nothing happens.  Gets rid of SOURCE by free ()ing it.
 148    Returns TARGET in case the location has changed. */
 149 extern char *sub_append_string PARAMS((char *, char *, size_t *, size_t *));
 150
 151 /* Append the textual representation of NUMBER to TARGET.
 152    INDEX and SIZE are as in SUB_APPEND_STRING. */
 153 extern char *sub_append_number PARAMS((intmax_t, char *, int *, int *));
 154
 155 /* Return the word list that corresponds to `$*'. */
 156 extern WORD_LIST *list_rest_of_args PARAMS((void));
 157
 158 /* Make a single large string out of the dollar digit variables,
 159    and the rest_of_args.  If DOLLAR_STAR is 1, then obey the special
 160    case of "$*" with respect to IFS. */
 161 extern char *string_rest_of_args PARAMS((int));
 162
 163 /* Expand STRING by performing parameter expansion, command substitution,
 164    and arithmetic expansion.  Dequote the resulting WORD_LIST before
 165    returning it, but do not perform word splitting.  The call to
 166    remove_quoted_nulls () is made here because word splitting normally
 167    takes care of quote removal. */
 168 extern WORD_LIST *expand_string_unsplit PARAMS((char *, int));
 169
 170 /* Expand the rhs of an assignment statement. */
 171 extern WORD_LIST *expand_string_assignment PARAMS((char *, int));
 172
 173 /* Expand a prompt string. */
 174 extern WORD_LIST *expand_prompt_string PARAMS((char *, int, int));
 175
 176 /* Expand STRING just as if you were expanding a word.  This also returns
 177    a list of words.  Note that filename globbing is *NOT* done for word
 178    or string expansion, just when the shell is expanding a command.  This
 179    does parameter expansion, command substitution, arithmetic expansion,
 180    and word splitting.  Dequote the resultant WORD_LIST before returning. */
 181 extern WORD_LIST *expand_string PARAMS((char *, int));
 182
 183 /* Convenience functions that expand strings to strings, taking care of
 184    converting the WORD_LIST * returned by the expand_string* functions
 185    to a string and deallocating the WORD_LIST *. */
 186 extern char *expand_string_to_string PARAMS((char *, int));
 187 extern char *expand_string_unsplit_to_string PARAMS((char *, int));
 188 extern char *expand_assignment_string_to_string PARAMS((char *, int));
 189 extern char *expand_subscript_string PARAMS((char *, int));
 190
 191 /* Expand an arithmetic expression string */
 192 extern char *expand_arith_string PARAMS((char *, int));
 193
 194 /* Expand $'...' and $"..." in a string for code paths that do not. */
 195 extern char *expand_string_dollar_quote PARAMS((char *, int));
 196
 197 /* De-quote quoted characters in STRING. */
 198 extern char *dequote_string PARAMS((char *));
 199
 200 /* De-quote CTLESC-escaped CTLESC or CTLNUL characters in STRING. */
 201 extern char *dequote_escapes PARAMS((const char *));
 202
 203 extern WORD_DESC *dequote_word PARAMS((WORD_DESC *));
 204
 205 /* De-quote quoted characters in each word in LIST. */
 206 extern WORD_LIST *dequote_list PARAMS((WORD_LIST *));
 207
 208 /* Expand WORD, performing word splitting on the result.  This does
 209    parameter expansion, command substitution, arithmetic expansion,
 210    word splitting, and quote removal. */
 211 extern WORD_LIST *expand_word PARAMS((WORD_DESC *, int));
 212
 213 /* Expand WORD, but do not perform word splitting on the result.  This
 214    does parameter expansion, command substitution, arithmetic expansion,
 215    and quote removal. */
 216 extern WORD_LIST *expand_word_unsplit PARAMS((WORD_DESC *, int));
 217 extern WORD_LIST *expand_word_leave_quoted PARAMS((WORD_DESC *, int));
 218
 219 /* Return the value of a positional parameter.  This handles values > 10. */
 220 extern char *get_dollar_var_value PARAMS((intmax_t));
 221
 222 /* Quote a string to protect it from word splitting. */
 223 extern char *quote_string PARAMS((char *));
 224
 225 /* Quote escape characters (characters special to internals of expansion)
 226    in a string. */
 227 extern char *quote_escapes PARAMS((const char *));
 228
 229 /* And remove such quoted special characters. */
 230 extern char *remove_quoted_escapes PARAMS((char *));
 231
 232 /* Remove CTLNUL characters from STRING unless they are quoted with CTLESC. */
 233 extern char *remove_quoted_nulls PARAMS((char *));
 234
 235 /* Perform quote removal on STRING.  If QUOTED > 0, assume we are obeying the
 236    backslash quoting rules for within double quotes. */
 237 extern char *string_quote_removal PARAMS((char *, int));
 238
 239 /* Perform quote removal on word WORD.  This allocates and returns a new
 240    WORD_DESC *. */
 241 extern WORD_DESC *word_quote_removal PARAMS((WORD_DESC *, int));
 242
 243 /* Perform quote removal on all words in LIST.  If QUOTED is non-zero,
 244    the members of the list are treated as if they are surrounded by
 245    double quotes.  Return a new list, or NULL if LIST is NULL. */
 246 extern WORD_LIST *word_list_quote_removal PARAMS((WORD_LIST *, int));
 247
 248 /* Called when IFS is changed to maintain some private variables. */
 249 extern void setifs PARAMS((SHELL_VAR *));
 250
 251 /* Return the value of $IFS, or " \t\n" if IFS is unset. */
 252 extern char *getifs PARAMS((void));
 253
 254 /* This splits a single word into a WORD LIST on $IFS, but only if the word
 255    is not quoted.  list_string () performs quote removal for us, even if we
 256    don't do any splitting. */
 257 extern WORD_LIST *word_split PARAMS((WORD_DESC *, char *));
 258
 259 /* Take the list of words in LIST and do the various substitutions.  Return
 260    a new list of words which is the expanded list, and without things like
 261    variable assignments. */
 262 extern WORD_LIST *expand_words PARAMS((WORD_LIST *));
 263
 264 /* Same as expand_words (), but doesn't hack variable or environment
 265    variables. */
 266 extern WORD_LIST *expand_words_no_vars PARAMS((WORD_LIST *));
 267
 268 /* Perform the `normal shell expansions' on a WORD_LIST.  These are
 269    brace expansion, tilde expansion, parameter and variable substitution,
 270    command substitution, arithmetic expansion, and word splitting. */
 271 extern WORD_LIST *expand_words_shellexp PARAMS((WORD_LIST *));
 272
 273 extern WORD_DESC *command_substitute PARAMS((char *, int, int));
 274 extern char *pat_subst PARAMS((char *, char *, char *, int));
 275
 276 #if defined (PROCESS_SUBSTITUTION)
 277 extern int fifos_pending PARAMS((void));
 278 extern int num_fifos PARAMS((void));
 279 extern void unlink_fifo_list PARAMS((void));
 280 extern void unlink_all_fifos PARAMS((void));
 281 extern void unlink_fifo PARAMS((int));
 282
 283 extern void *copy_fifo_list PARAMS((int *));
 284 extern void close_new_fifos PARAMS((void *, int));
 285
 286 extern void clear_fifo_list PARAMS((void));
 287
 288 extern int find_procsub_child PARAMS((pid_t));
 289 extern void set_procsub_status PARAMS((int, pid_t, int));
 290
 291 extern void wait_procsubs PARAMS((void));
 292 extern void reap_procsubs PARAMS((void));
 293 #endif
 294
 295 extern WORD_LIST *list_string_with_quotes PARAMS((char *));
 296
 297 #if defined (ARRAY_VARS)
 298 extern char *extract_array_assignment_list PARAMS((char *, int *));
 299 #endif
 300
 301 #if defined (COND_COMMAND)
 302 extern char *remove_backslashes PARAMS((char *));
 303 extern char *cond_expand_word PARAMS((WORD_DESC *, int));
 304 #endif
 305
 306 /* Flags for skip_to_delim */
 307 #define SD_NOJMP        0x001   /* don't longjmp on fatal error. */
 308 #define SD_INVERT       0x002   /* look for chars NOT in passed set */
 309 #define SD_NOQUOTEDELIM 0x004   /* don't let single or double quotes act as delimiters */
 310 #define SD_NOSKIPCMD    0x008   /* don't skip over $(, <(, or >( command/process substitution; parse them as commands */
 311 #define SD_EXTGLOB      0x010   /* skip over extended globbing patterns if appropriate */
 312 #define SD_IGNOREQUOTE  0x020   /* single and double quotes are not special */
 313 #define SD_GLOB         0x040   /* skip over glob patterns like bracket expressions */
 314 #define SD_NOPROCSUB    0x080   /* don't parse process substitutions as commands */
 315 #define SD_COMPLETE     0x100   /* skip_to_delim during completion */
 316 #define SD_HISTEXP      0x200   /* skip_to_delim during history expansion */
 317 #define SD_ARITHEXP     0x400   /* skip_to_delim during arithmetic expansion */
 318 #define SD_NOERROR      0x800   /* don't print error messages */
 319
 320 extern int skip_to_delim PARAMS((char *, int, char *, int));
 321
 322 #if defined (BANG_HISTORY)
 323 extern int skip_to_histexp PARAMS((char *, int, char *, int));
 324 #endif
 325
 326 #if defined (READLINE)
 327 extern int char_is_quoted PARAMS((char *, int));
 328 extern int unclosed_pair PARAMS((char *, int, char *));
 329 extern WORD_LIST *split_at_delims PARAMS((char *, int, const char *, int, int, int *, int *));
 330 #endif
 331
 332 /* Variables used to keep track of the characters in IFS. */
 333 extern SHELL_VAR *ifs_var;
 334 extern char *ifs_value;
 335 extern unsigned char ifs_cmap[];
 336 extern int ifs_is_set, ifs_is_null;
 337
 338 #if defined (HANDLE_MULTIBYTE)
 339 extern unsigned char ifs_firstc[];
 340 extern size_t ifs_firstc_len;
 341 #else
 342 extern unsigned char ifs_firstc;
 343 #endif
 344
 345 extern int assigning_in_environment;
 346 extern int expanding_redir;
 347 extern int inherit_errexit;
 348
 349 extern pid_t last_command_subst_pid;
 350
 351 /* Evaluates to 1 if C is a character in $IFS. */
 352 #define isifs(c)        (ifs_cmap[(unsigned char)(c)] != 0)
 353
 354 /* How to determine the quoted state of the character C. */
 355 #define QUOTED_CHAR(c)  ((c) == CTLESC)
 356
 357 /* Is the first character of STRING a quoted NULL character? */
 358 #define QUOTED_NULL(string) ((string)[0] == CTLNUL && (string)[1] == '\0')
 359
 360 extern void invalidate_cached_quoted_dollar_at PARAMS((void));
 361
 362 #endif /* !_SUBST_H_ */