path: root/subst.h

/* subst.h -- Names of externally visible functions in subst.c. */

/* Copyright (C) 1993-2021 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Bash is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#if !defined (_SUBST_H_)
#define _SUBST_H_

#include "stdc.h"

/* Constants which specify how to handle backslashes and quoting in
   expand_word_internal ().  Q_DOUBLE_QUOTES means to use the function
   slashify_in_quotes () to decide whether the backslash should be
   retained.  Q_HERE_DOCUMENT means slashify_in_here_document () to
   decide whether to retain the backslash.  Q_KEEP_BACKSLASH means
   to unconditionally retain the backslash.  Q_PATQUOTE means that we're
   expanding a pattern ${var%#[#%]pattern} in an expansion surrounded
   by double quotes. Q_DOLBRACE means we are expanding a ${...} word, so
   backslashes should also escape { and } and be removed. */
#define Q_DOUBLE_QUOTES  0x001
#define Q_HERE_DOCUMENT  0x002
#define Q_KEEP_BACKSLASH 0x004
#define Q_PATQUOTE	 0x008
#define Q_QUOTED	 0x010
#define Q_ADDEDQUOTES	 0x020
#define Q_QUOTEDNULL	 0x040
#define Q_DOLBRACE	 0x080
#define Q_ARITH		 0x100	/* expanding string for arithmetic evaluation */
#define Q_ARRAYSUB	 0x200	/* expanding indexed array subscript */

/* Flag values controlling how assignment statements are treated. */
#define ASS_APPEND	0x0001
#define ASS_MKLOCAL	0x0002
#define ASS_MKASSOC	0x0004
#define ASS_MKGLOBAL	0x0008	/* force global assignment */
#define ASS_NAMEREF	0x0010	/* assigning to nameref variable */
#define ASS_FORCE	0x0020	/* force assignment even to readonly variable */
#define ASS_CHKLOCAL	0x0040	/* check local variable before assignment */
#define ASS_NOEXPAND	0x0080	/* don't expand associative array subscripts */
#define ASS_NOEVAL	0x0100	/* don't evaluate value as expression */
#define ASS_NOLONGJMP	0x0200	/* don't longjmp on fatal assignment error */
#define ASS_NOINVIS	0x0400	/* don't resolve local invisible variables */
#define ASS_ALLOWALLSUB	0x0800	/* allow * and @ as associative array keys */
#define ASS_ONEWORD	0x1000	/* don't check array subscripts, assume higher level has done that */

/* Flags for the string extraction functions. */
#define SX_NOALLOC	0x0001	/* just skip; don't return substring */
#define SX_VARNAME	0x0002	/* variable name; for string_extract () */
#define SX_REQMATCH	0x0004	/* closing/matching delimiter required */
#define SX_COMMAND	0x0008	/* extracting a shell script/command */
#define SX_NOCTLESC	0x0010	/* don't honor CTLESC quoting */
#define SX_NOESCCTLNUL	0x0020	/* don't let CTLESC quote CTLNUL */
#define SX_NOLONGJMP	0x0040	/* don't longjmp on fatal error */
#define SX_ARITHSUB	0x0080	/* extracting $(( ... )) (currently unused) */
#define SX_POSIXEXP	0x0100	/* extracting new Posix pattern removal expansions in extract_dollar_brace_string */
#define SX_WORD		0x0200	/* extracting word in ${param op word} */
#define SX_COMPLETE	0x0400	/* extracting word for completion */
#define SX_STRIPDQ	0x0800	/* strip double quotes when extracting double-quoted string */
#define SX_NOERROR	0x1000	/* don't print parser error messages */

/* Remove backslashes which are quoting backquotes from STRING.  Modifies
   STRING, and returns a pointer to it. */
extern char * de_backslash PARAMS((char *));

/* Replace instances of \! in a string with !. */
extern void unquote_bang PARAMS((char *));

/* Extract the $( construct in STRING, and return a new string.
   Start extracting at (SINDEX) as if we had just seen "$(".
   Make (SINDEX) get the position just after the matching ")".
   XFLAGS is additional flags to pass to other extraction functions, */
extern char *extract_command_subst PARAMS((char *, int *, int));

/* Extract the $[ construct in STRING, and return a new string.
   Start extracting at (SINDEX) as if we had just seen "$[".
   Make (SINDEX) get the position just after the matching "]". */
extern char *extract_arithmetic_subst PARAMS((char *, int *));

#if defined (PROCESS_SUBSTITUTION)
/* Extract the <( or >( construct in STRING, and return a new string.
   Start extracting at (SINDEX) as if we had just seen "<(".
   Make (SINDEX) get the position just after the matching ")". */
extern char *extract_process_subst PARAMS((char *, char *, int *, int));
#endif /* PROCESS_SUBSTITUTION */

/* Extract the name of the variable to bind to from the assignment string. */
extern char *assignment_name PARAMS((char *));

/* Return a single string of all the words present in LIST, separating
   each word with SEP. */
extern char *string_list_internal PARAMS((WORD_LIST *, char *));

/* Return a single string of all the words present in LIST, separating
   each word with a space. */
extern char *string_list PARAMS((WORD_LIST *));

/* Turn $* into a single string, obeying POSIX rules. */
extern char *string_list_dollar_star PARAMS((WORD_LIST *, int, int));

/* Expand $@ into a single string, obeying POSIX rules. */
extern char *string_list_dollar_at PARAMS((WORD_LIST *, int, int));

/* Turn the positional parameters into a string, understanding quoting and
   the various subtleties of using the first character of $IFS as the
   separator.  Calls string_list_dollar_at, string_list_dollar_star, and
   string_list as appropriate. */
extern char *string_list_pos_params PARAMS((int, WORD_LIST *, int, int));

/* Perform quoted null character removal on each element of LIST.
   This modifies LIST. */
extern void word_list_remove_quoted_nulls PARAMS((WORD_LIST *));

/* This performs word splitting and quoted null character removal on
   STRING. */
extern WORD_LIST *list_string PARAMS((char *, char *, int));

extern char *ifs_firstchar  PARAMS((int *));
extern char *get_word_from_string PARAMS((char **, char *, char **));
extern char *strip_trailing_ifs_whitespace PARAMS((char *, char *, int));

/* Given STRING, an assignment string, get the value of the right side
   of the `=', and bind it to the left side.  If EXPAND is true, then
   perform tilde expansion, parameter expansion, command substitution,
   and arithmetic expansion on the right-hand side.  Do not perform word
   splitting on the result of expansion. */
extern int do_assignment PARAMS((char *));
extern int do_assignment_no_expand PARAMS((char *));
extern int do_word_assignment PARAMS((WORD_DESC *, int));

/* Append SOURCE to TARGET at INDEX.  SIZE is the current amount
   of space allocated to TARGET.  SOURCE can be NULL, in which
   case nothing happens.  Gets rid of SOURCE by free ()ing it.
   Returns TARGET in case the location has changed. */
extern char *sub_append_string PARAMS((char *, char *, size_t *, size_t *));

/* Append the textual representation of NUMBER to TARGET.
   INDEX and SIZE are as in SUB_APPEND_STRING. */
extern char *sub_append_number PARAMS((intmax_t, char *, int *, int *));

/* Return the word list that corresponds to `$*'. */
extern WORD_LIST *list_rest_of_args PARAMS((void));

/* Make a single large string out of the dollar digit variables,
   and the rest_of_args.  If DOLLAR_STAR is 1, then obey the special
   case of "$*" with respect to IFS. */
extern char *string_rest_of_args PARAMS((int));

/* Expand STRING by performing parameter expansion, command substitution,
   and arithmetic expansion.  Dequote the resulting WORD_LIST before
   returning it, but do not perform word splitting.  The call to
   remove_quoted_nulls () is made here because word splitting normally
   takes care of quote removal. */
extern WORD_LIST *expand_string_unsplit PARAMS((char *, int));

/* Expand the rhs of an assignment statement. */
extern WORD_LIST *expand_string_assignment PARAMS((char *, int));

/* Expand a prompt string. */
extern WORD_LIST *expand_prompt_string PARAMS((char *, int, int));

/* Expand STRING just as if you were expanding a word.  This also returns
   a list of words.  Note that filename globbing is *NOT* done for word
   or string expansion, just when the shell is expanding a command.  This
   does parameter expansion, command substitution, arithmetic expansion,
   and word splitting.  Dequote the resultant WORD_LIST before returning. */
extern WORD_LIST *expand_string PARAMS((char *, int));

/* Convenience functions that expand strings to strings, taking care of
   converting the WORD_LIST * returned by the expand_string* functions
   to a string and deallocating the WORD_LIST *. */
extern char *expand_string_to_string PARAMS((char *, int));
extern char *expand_string_unsplit_to_string PARAMS((char *, int));
extern char *expand_assignment_string_to_string PARAMS((char *, int));
extern char *expand_subscript_string PARAMS((char *, int));

/* Expand an arithmetic expression string */
extern char *expand_arith_string PARAMS((char *, int));

/* Expand $'...' and $"..." in a string for code paths that do not. */
extern char *expand_string_dollar_quote PARAMS((char *, int));

/* De-quote quoted characters in STRING. */
extern char *dequote_string PARAMS((char *));

/* De-quote CTLESC-escaped CTLESC or CTLNUL characters in STRING. */
extern char *dequote_escapes PARAMS((const char *));

extern WORD_DESC *dequote_word PARAMS((WORD_DESC *));

/* De-quote quoted characters in each word in LIST. */
extern WORD_LIST *dequote_list PARAMS((WORD_LIST *));

/* Expand WORD, performing word splitting on the result.  This does
   parameter expansion, command substitution, arithmetic expansion,
   word splitting, and quote removal. */
extern WORD_LIST *expand_word PARAMS((WORD_DESC *, int));

/* Expand WORD, but do not perform word splitting on the result.  This
   does parameter expansion, command substitution, arithmetic expansion,
   and quote removal. */
extern WORD_LIST *expand_word_unsplit PARAMS((WORD_DESC *, int));
extern WORD_LIST *expand_word_leave_quoted PARAMS((WORD_DESC *, int));

/* Return the value of a positional parameter.  This handles values > 10. */
extern char *get_dollar_var_value PARAMS((intmax_t));

/* Quote a string to protect it from word splitting. */
extern char *quote_string PARAMS((char *));

/* Quote escape characters (characters special to internals of expansion)
   in a string. */
extern char *quote_escapes PARAMS((const char *));

/* And remove such quoted special characters. */
extern char *remove_quoted_escapes PARAMS((char *));

/* Remove CTLNUL characters from STRING unless they are quoted with CTLESC. */
extern char *remove_quoted_nulls PARAMS((char *));

/* Perform quote removal on STRING.  If QUOTED > 0, assume we are obeying the
   backslash quoting rules for within double quotes. */
extern char *string_quote_removal PARAMS((char *, int));

/* Perform quote removal on word WORD.  This allocates and returns a new
   WORD_DESC *. */
extern WORD_DESC *word_quote_removal PARAMS((WORD_DESC *, int));

/* Perform quote removal on all words in LIST.  If QUOTED is non-zero,
   the members of the list are treated as if they are surrounded by
   double quotes.  Return a new list, or NULL if LIST is NULL. */
extern WORD_LIST *word_list_quote_removal PARAMS((WORD_LIST *, int));

/* Called when IFS is changed to maintain some private variables. */
extern void setifs PARAMS((SHELL_VAR *));

/* Return the value of $IFS, or " \t\n" if IFS is unset. */
extern char *getifs PARAMS((void));

/* This splits a single word into a WORD LIST on $IFS, but only if the word
   is not quoted.  list_string () performs quote removal for us, even if we
   don't do any splitting. */
extern WORD_LIST *word_split PARAMS((WORD_DESC *, char *));

/* Take the list of words in LIST and do the various substitutions.  Return
   a new list of words which is the expanded list, and without things like
   variable assignments. */
extern WORD_LIST *expand_words PARAMS((WORD_LIST *));

/* Same as expand_words (), but doesn't hack variable or environment
   variables. */
extern WORD_LIST *expand_words_no_vars PARAMS((WORD_LIST *));

/* Perform the `normal shell expansions' on a WORD_LIST.  These are
   brace expansion, tilde expansion, parameter and variable substitution,
   command substitution, arithmetic expansion, and word splitting. */
extern WORD_LIST *expand_words_shellexp PARAMS((WORD_LIST *));

extern WORD_DESC *command_substitute PARAMS((char *, int, int));
extern char *pat_subst PARAMS((char *, char *, char *, int));

#if defined (PROCESS_SUBSTITUTION)
extern int fifos_pending PARAMS((void));
extern int num_fifos PARAMS((void));
extern void unlink_fifo_list PARAMS((void));
extern void unlink_all_fifos PARAMS((void));
extern void unlink_fifo PARAMS((int));

extern void *copy_fifo_list PARAMS((int *));
extern void close_new_fifos PARAMS((void *, int));

extern void clear_fifo_list PARAMS((void));

extern int find_procsub_child PARAMS((pid_t));
extern void set_procsub_status PARAMS((int, pid_t, int));

extern void wait_procsubs PARAMS((void));
extern void reap_procsubs PARAMS((void));
#endif

extern WORD_LIST *list_string_with_quotes PARAMS((char *));

#if defined (ARRAY_VARS)
extern char *extract_array_assignment_list PARAMS((char *, int *));
#endif

#if defined (COND_COMMAND)
extern char *remove_backslashes PARAMS((char *));
extern char *cond_expand_word PARAMS((WORD_DESC *, int));
#endif

/* Flags for skip_to_delim */
#define SD_NOJMP	0x001	/* don't longjmp on fatal error. */
#define SD_INVERT	0x002	/* look for chars NOT in passed set */
#define SD_NOQUOTEDELIM	0x004	/* don't let single or double quotes act as delimiters */
#define SD_NOSKIPCMD	0x008	/* don't skip over $(, <(, or >( command/process substitution; parse them as commands */
#define SD_EXTGLOB	0x010	/* skip over extended globbing patterns if appropriate */
#define SD_IGNOREQUOTE	0x020	/* single and double quotes are not special */
#define SD_GLOB		0x040	/* skip over glob patterns like bracket expressions */
#define SD_NOPROCSUB	0x080	/* don't parse process substitutions as commands */
#define SD_COMPLETE	0x100	/* skip_to_delim during completion */
#define SD_HISTEXP	0x200	/* skip_to_delim during history expansion */
#define SD_ARITHEXP	0x400	/* skip_to_delim during arithmetic expansion */
#define SD_NOERROR	0x800	/* don't print error messages */

extern int skip_to_delim PARAMS((char *, int, char *, int));

#if defined (BANG_HISTORY)
extern int skip_to_histexp PARAMS((char *, int, char *, int));
#endif

#if defined (READLINE)
extern int char_is_quoted PARAMS((char *, int));
extern int unclosed_pair PARAMS((char *, int, char *));
extern WORD_LIST *split_at_delims PARAMS((char *, int, const char *, int, int, int *, int *));
#endif

/* Variables used to keep track of the characters in IFS. */
extern SHELL_VAR *ifs_var;
extern char *ifs_value;
extern unsigned char ifs_cmap[];
extern int ifs_is_set, ifs_is_null;

#if defined (HANDLE_MULTIBYTE)
extern unsigned char ifs_firstc[];
extern size_t ifs_firstc_len;
#else
extern unsigned char ifs_firstc;
#endif

extern int assigning_in_environment;
extern int expanding_redir;
extern int inherit_errexit;

extern pid_t last_command_subst_pid;

/* Evaluates to 1 if C is a character in $IFS. */
#define isifs(c)	(ifs_cmap[(unsigned char)(c)] != 0)

/* How to determine the quoted state of the character C. */
#define QUOTED_CHAR(c)  ((c) == CTLESC)

/* Is the first character of STRING a quoted NULL character? */
#define QUOTED_NULL(string) ((string)[0] == CTLNUL && (string)[1] == '\0')

extern void invalidate_cached_quoted_dollar_at PARAMS((void));

#endif /* !_SUBST_H_ */