1 /* braces.c -- code for doing word expansion in curly braces. */
3 /* Copyright (C) 1987,1991 Free Software Foundation, Inc.
5 This file is part of GNU Bash, the Bourne Again SHell.
7 Bash is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 Bash is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
17 You should have received a copy of the GNU General Public License
18 along with Bash; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
21 /* Stuff in curly braces gets expanded before all other shell expansions. */
25 #if defined (BRACE_EXPANSION)
27 #if defined (HAVE_UNISTD_H)
29 # include <sys/types.h>
41 #define brace_whitespace(c) (!(c) || (c) == ' ' || (c) == '\t' || (c) == '\n')
45 Segregate the text into 3 sections: preamble (stuff before an open brace),
46 postamble (stuff after the matching close brace) and amble (stuff after
47 preamble, and before postamble). Expand amble, and then tack on the
48 expansions to preamble. Expand postamble, and tack on the expansions to
52 /* The character which is used to separate arguments. */
53 int brace_arg_separator = ',';
56 static int brace_gobbler __P((char *, int *, int));
57 static char **expand_amble __P((char *));
58 static char **array_concat __P((char **, char **));
60 static int brace_gobbler ();
61 static char **expand_amble ();
62 static char **array_concat ();
65 /* Return an array of strings; the brace expansion of TEXT. */
71 char *preamble, *postamble, *amble;
72 char **tack, **result;
75 /* Find the text of the preamble. */
77 c = brace_gobbler (text, &i, '{');
79 preamble = (char *)xmalloc (i + 1);
80 strncpy (preamble, text, i);
83 result = (char **)xmalloc (2 * sizeof (char *));
85 result[1] = (char *)NULL;
87 /* Special case. If we never found an exciting character, then
88 the preamble is all of the text, so just return that. */
92 /* Find the amble. This is the stuff inside this set of braces. */
94 c = brace_gobbler (text, &i, '}');
96 /* What if there isn't a matching close brace? */
100 /* Well, if we found an unquoted BRACE_ARG_SEPARATOR between START
101 and I, then this should be an error. Otherwise, it isn't. */
102 for (j = start; j < i; j++)
110 if (text[j] == brace_arg_separator)
113 report_error ("missing `}'");
114 throw_to_top_level ();
118 free (preamble); /* Same as result[0]; see initialization. */
119 result[0] = savestring (text);
124 amble = substring (text, start, i);
126 amble = (char *)xmalloc (1 + (i - start));
127 strncpy (amble, &text[start], (i - start));
128 amble[i - start] = '\0';
132 /* If the amble does not contain an unquoted BRACE_ARG_SEPARATOR, then
133 just return without doing any expansion. */
134 for (j = 0; amble[j]; j++)
136 if (amble[j] == '\\')
141 if (amble[j] == brace_arg_separator)
149 result[0] = savestring (text);
154 postamble = &text[i + 1];
156 tack = expand_amble (amble);
157 result = array_concat (result, tack);
161 tack = brace_expand (postamble);
162 result = array_concat (result, tack);
168 /* Expand the text found inside of braces. We simply try to split the
169 text at BRACE_ARG_SEPARATORs into separate strings. We then brace
170 expand each slot which needs it, until there are no more slots which
176 char **result, **partial;
180 result = (char **)NULL;
182 for (start = 0, i = 0, c = 1; c; start = ++i)
184 c = brace_gobbler (text, &i, brace_arg_separator);
186 tem = substring (text, start, i);
188 tem = (char *)xmalloc (1 + (i - start));
189 strncpy (tem, &text[start], (i - start));
190 tem[i- start] = '\0';
193 partial = brace_expand (tem);
199 register int lr = array_len (result);
200 register int lp = array_len (partial);
203 result = (char **)xrealloc (result, (1 + lp + lr) * sizeof (char *));
205 for (j = 0; j < lp; j++)
206 result[lr + j] = partial[j];
208 result[lr + j] = (char *)NULL;
216 /* Start at INDEX, and skip characters in TEXT. Set INDEX to the
217 index of the character matching SATISFY. This understands about
218 quoting. Return the character that caused us to stop searching;
219 this is either the same as SATISFY, or 0. */
221 brace_gobbler (text, indx, satisfy)
226 register int i, c, quoted, level, pass_next;
232 level = quoted = pass_next = 0;
234 for (i = *indx; c = text[i]; i++)
242 /* A backslash escapes the next character. This allows backslash to
243 escape the quote character in a double-quoted string. */
244 if (c == '\\' && (quoted == 0 || quoted == '"' || quoted == '`'))
257 if (c == '"' || c == '\'' || c == '`')
264 /* Pass new-style command substitutions through unchanged. */
265 if (c == '$' && text[i+1] == '(') /* ) */
268 t = extract_command_subst (text, &si);
275 if (c == satisfy && level == 0 && quoted == 0)
277 /* We ignore an open brace surrounded by whitespace, and also
278 an open brace followed immediately by a close brace preceded
281 ((!i || brace_whitespace (text[i - 1])) &&
282 (brace_whitespace (text[i + 1]) || text[i + 1] == '}')))
285 /* If this is being compiled as part of bash, ignore the `{'
286 in a `${}' construct */
287 if ((c != '{') || i == 0 || (text[i - 1] != '$'))
294 else if (c == '}' && level)
302 /* Return a new array of strings which is the result of appending each
303 string in ARR2 to each string in ARR1. The resultant array is
304 len (arr1) * len (arr2) long. For convenience, ARR1 (and its contents)
305 are free ()'ed. ARR1 can be NULL, in that case, a new version of ARR2
308 array_concat (arr1, arr2)
311 register int i, j, len, len1, len2;
312 register char **result;
315 return (copy_array (arr2));
318 return (copy_array (arr1));
320 len1 = array_len (arr1);
321 len2 = array_len (arr2);
323 result = (char **)xmalloc ((1 + (len1 * len2)) * sizeof (char *));
326 for (i = 0; i < len1; i++)
328 int strlen_1 = strlen (arr1[i]);
330 for (j = 0; j < len2; j++)
333 (char *)xmalloc (1 + strlen_1 + strlen (arr2[j]));
334 strcpy (result[len], arr1[i]);
335 strcpy (result[len] + strlen_1, arr2[j]);
342 result[len] = (char *)NULL;
349 fatal_error (format, arg1, arg2)
350 char *format, *arg1, *arg2;
352 report_error (format, arg1, arg2);
356 report_error (format, arg1, arg2)
357 char *format, *arg1, *arg2;
359 fprintf (stderr, format, arg1, arg2);
360 fprintf (stderr, "\n");
372 fprintf (stderr, "brace_expand> ");
374 if ((!fgets (example, 256, stdin)) ||
375 (strncmp (example, "quit", 4) == 0))
378 if (strlen (example))
379 example[strlen (example) - 1] = '\0';
381 result = brace_expand (example);
383 for (i = 0; result[i]; i++)
384 printf ("%s\n", result[i]);
392 * compile-command: "gcc -g -Bstatic -DTEST -o brace_expand braces.c general.o"
397 #endif /* BRACE_EXPANSION */