bash-2.02.tar.gz

/* subst.c -- The part of the shell that does parameter, command, and globbing substitutions. */ /* Copyright (C) 1987,1989 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 2, 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; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "config.h" #include "bashtypes.h" #include <stdio.h> #include <pwd.h> #include <signal.h> #include <errno.h> #if defined (HAVE_UNISTD_H) # include <unistd.h> #endif #include "bashansi.h" #include "posixstat.h" #include "shell.h" #include "flags.h" #include "jobs.h" #include "execute_cmd.h" #include "filecntl.h" #include "trap.h" #include "pathexp.h" #include "mailcheck.h" #if !defined (HAVE_RESTARTABLE_SYSCALLS) /* for getc_with_restart */ #include "input.h" #endif #include "builtins/getopt.h" #include "builtins/common.h" #include <tilde/tilde.h> #include <glob/fnmatch.h> #if !defined (errno) extern int errno; #endif /* !errno */ /* The size that strings change by. */ #define DEFAULT_INITIAL_ARRAY_SIZE 112 #define DEFAULT_ARRAY_SIZE 128 /* Variable types. */ #define VT_VARIABLE 0 #define VT_POSPARMS 1 #define VT_ARRAYVAR 2 #define VT_ARRAYMEMBER 3 /* Flags for quoted_strchr */ #define ST_BACKSL 0x01 #define ST_CTLESC 0x02 /* These defs make it easier to use the editor. */ #define LBRACE '{' #define RBRACE '}' #define LPAREN '(' #define RPAREN ')' /* Process ID of the last command executed within command substitution. */ pid_t last_command_subst_pid = NO_PID; /* Extern functions and variables from different files. */ extern int last_command_exit_value, interactive, interactive_shell; extern int subshell_environment, startup_state; extern int dollar_dollar_pid; extern int posixly_correct; extern char *this_command_name; extern struct fd_bitmap *current_fds_to_close; extern int wordexp_only; extern void getopts_reset (); /* Non-zero means to allow unmatched globbed filenames to expand to a null file. */ int allow_null_glob_expansion; /* Variables to keep track of which words in an expanded word list (the output of expand_word_list_internal) are the result of globbing expansions. GLOB_ARGV_FLAGS is used by execute_cmd.c. */ char *glob_argv_flags; static int glob_argv_flags_size; static WORD_LIST expand_word_error, expand_word_fatal; static char expand_param_error, expand_param_fatal; static char *make_quoted_char (); static void remove_quoted_nulls (); static char *param_expand (); static char *maybe_expand_string (); static WORD_LIST *call_expand_word_internal (); static WORD_LIST *expand_string_internal (); static WORD_LIST *expand_word_internal (), *expand_word_list_internal (); static WORD_LIST *expand_string_leave_quoted (); static WORD_LIST *expand_string_for_rhs (); static WORD_LIST *word_list_split (); static WORD_LIST *quote_list (), *dequote_list (); static char *quote_escapes (); static WORD_LIST *list_quote_escapes (); static int unquoted_substring (), unquoted_member (); static int do_assignment_internal (); static char *string_extract_verbatim (), *string_extract (); static char *string_extract_double_quoted (), *string_extract_single_quoted (); static char *string_list_dollar_at (), *string_list_dollar_star (); static inline int skip_single_quoted (), skip_double_quoted (); static char *extract_delimited_string (); static char *extract_dollar_brace_string (); /* **************************************************************** */ /* */ /* Utility Functions */ /* */ /* **************************************************************** */ /* Cons a new string from STRING starting at START and ending at END, not including END. */ char * substring (string, start, end) char *string; int start, end; { register int len; register char *result; len = end - start; result = xmalloc (len + 1); strncpy (result, string + start, len); result[len] = '\0'; return (result); } static char * quoted_substring (string, start, end) char *string; int start, end; { register int len, l; register char *result, *s, *r; len = end - start; /* Move to string[start], skipping quoted characters. */ for (s = string, l = 0; *s && l < start; ) { if (*s == CTLESC) { s++; continue; } l++; if (*s == 0) break; } r = result = xmalloc (2*len + 1); /* save room for quotes */ /* Copy LEN characters, including quote characters. */ s = string + l; for (l = 0; l < len; s++) { if (*s == CTLESC) *r++ = *s++; *r++ = *s; l++; if (*s == 0) break; } *r = '\0'; return result; } /* Find the first occurrence of character C in string S, obeying shell quoting rules. If (FLAGS & ST_BACKSL) is non-zero, backslash-escaped characters are skipped. If (FLAGS & ST_CTLESC) is non-zero, characters escaped with CTLESC are skipped. */ static inline char * quoted_strchr (s, c, flags) char *s; int c, flags; { register char *p; for (p = s; *p; p++) { if (((flags & ST_BACKSL) && *p == '\\') || ((flags & ST_CTLESC) && *p == CTLESC)) { p++; if (*p == '\0') return ((char *)NULL); continue; } else if (*p == c) return p; } return ((char *)NULL); } /* Return 1 if CHARACTER appears in an unquoted portion of STRING. Return 0 otherwise. */ static int unquoted_member (character, string) int character; char *string; { int sindex, c; for (sindex = 0; c = string[sindex]; ) { if (c == character) return (1); switch (c) { default: sindex++; break; case '\\': sindex++; if (string[sindex]) sindex++; break; case '\'': sindex = skip_single_quoted (string, ++sindex); break; case '"': sindex = skip_double_quoted (string, ++sindex); break; } } return (0); } /* Return 1 if SUBSTR appears in an unquoted portion of STRING. */ static int unquoted_substring (substr, string) char *substr, *string; { int sindex, c, sublen; if (substr == 0 || *substr == '\0') return (0); sublen = strlen (substr); for (sindex = 0; c = string[sindex]; ) { if (STREQN (string + sindex, substr, sublen)) return (1); switch (c) { case '\\': sindex++; if (string[sindex]) sindex++; break; case '\'': sindex = skip_single_quoted (string, ++sindex); break; case '"': sindex = skip_double_quoted (string, ++sindex); break; default: sindex++; break; } } return (0); } /* Most of the substitutions must be done in parallel. In order to avoid using tons of unclear goto's, I have some functions for manipulating malloc'ed strings. They all take INDX, a pointer to an integer which is the offset into the string where manipulation is taking place. They also take SIZE, a pointer to an integer which is the current length of the character array for this string. */ /* 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 freeing it. Returns TARGET in case the location has changed. */ inline char * sub_append_string (source, target, indx, size) char *source, *target; int *indx, *size; { if (source) { int srclen, n; srclen = STRLEN (source); if (srclen >=