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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* Stuff in curly braces gets expanded before all other shell expansions. */
25 #if defined (BRACE_EXPANSION)
27 #if defined (HAVE_UNISTD_H)
31 #if defined (HAVE_STRING_H)
33 #else /* !HAVE_STRING_H */
35 #endif /* !HAVE_STRING_H */
42 #define brace_whitespace(c) (!(c) || (c) == ' ' || (c) == '\t' || (c) == '\n')
46 Segregate the text into 3 sections: preamble (stuff before an open brace),
47 postamble (stuff after the matching close brace) and amble (stuff after
48 preamble, and before postamble). Expand amble, and then tack on the
49 expansions to preamble. Expand postamble, and tack on the expansions to
53 /* The character which is used to separate arguments. */
54 int brace_arg_separator = ',';
56 static int brace_gobbler ();
57 static char **expand_amble (), **array_concat ();
59 /* Return an array of strings; the brace expansion of TEXT. */
65 char *preamble, *postamble, *amble;
66 char **tack, **result;
69 /* Find the text of the preamble. */
71 c = brace_gobbler (text, &i, '{');
73 preamble = (char *)xmalloc (i + 1);
74 strncpy (preamble, text, i);
77 result = (char **)xmalloc (2 * sizeof (char *));
79 result[1] = (char *)NULL;
81 /* Special case. If we never found an exciting character, then
82 the preamble is all of the text, so just return that. */
86 /* Find the amble. This is the stuff inside this set of braces. */
88 c = brace_gobbler (text, &i, '}');
90 /* What if there isn't a matching close brace? */
94 /* Well, if we found an unquoted BRACE_ARG_SEPARATOR between START
95 and I, then this should be an error. Otherwise, it isn't. */
96 for (j = start; j < i; j++)
104 if (text[j] == brace_arg_separator)
107 report_error ("missing `}'");
108 throw_to_top_level ();
112 free (preamble); /* Same as result[0]; see initialization. */
113 result[0] = savestring (text);
117 amble = (char *)xmalloc (1 + (i - start));
118 strncpy (amble, &text[start], (i - start));
119 amble[i - start] = '\0';
122 /* If the amble does not contain an unquoted BRACE_ARG_SEPARATOR, then
123 just return without doing any expansion. */
124 for (j = 0; amble[j]; j++)
126 if (amble[j] == '\\')
131 if (amble[j] == brace_arg_separator)
139 result[0] = savestring (text);
144 postamble = &text[i + 1];
146 tack = expand_amble (amble);
147 result = array_concat (result, tack);
151 tack = brace_expand (postamble);
152 result = array_concat (result, tack);
158 /* Expand the text found inside of braces. We simply try to split the
159 text at BRACE_ARG_SEPARATORs into separate strings. We then brace
160 expand each slot which needs it, until there are no more slots which
166 char **result, **partial;
170 result = (char **)NULL;
172 for (start = 0, i = 0, c = 1; c; start = ++i)
174 c = brace_gobbler (text, &i, brace_arg_separator);
175 tem = (char *)xmalloc (1 + (i - start));
176 strncpy (tem, &text[start], (i - start));
177 tem[i- start] = '\0';
179 partial = brace_expand (tem);
185 register int lr = array_len (result);
186 register int lp = array_len (partial);
189 result = (char **)xrealloc (result, (1 + lp + lr) * sizeof (char *));
191 for (j = 0; j < lp; j++)
192 result[lr + j] = partial[j];
194 result[lr + j] = (char *)NULL;
202 /* Start at INDEX, and skip characters in TEXT. Set INDEX to the
203 index of the character matching SATISFY. This understands about
204 quoting. Return the character that caused us to stop searching;
205 this is either the same as SATISFY, or 0. */
207 brace_gobbler (text, indx, satisfy)
212 register int i, c, quoted, level, pass_next;
214 level = quoted = pass_next = 0;
216 for (i = *indx; c = text[i]; i++)
224 /* A backslash escapes the next character. This allows backslash to
225 escape the quote character in a double-quoted string. */
226 if (c == '\\' && (quoted == 0 || quoted == '"' || quoted == '`'))
239 if (c == '"' || c == '\'' || c == '`')
245 if (c == satisfy && level == 0 && quoted == 0)
247 /* We ignore an open brace surrounded by whitespace, and also
248 an open brace followed immediately by a close brace preceded
251 ((!i || brace_whitespace (text[i - 1])) &&
252 (brace_whitespace (text[i + 1]) || text[i + 1] == '}')))
255 /* If this is being compiled as part of bash, ignore the `{'
256 in a `${}' construct */
257 if ((c != '{') || i == 0 || (text[i - 1] != '$'))
264 else if (c == '}' && level)
272 /* Return a new array of strings which is the result of appending each
273 string in ARR2 to each string in ARR1. The resultant array is
274 len (arr1) * len (arr2) long. For convenience, ARR1 (and its contents)
275 are free ()'ed. ARR1 can be NULL, in that case, a new version of ARR2
278 array_concat (arr1, arr2)
281 register int i, j, len, len1, len2;
282 register char **result;
285 return (copy_array (arr2));
288 return (copy_array (arr1));
290 len1 = array_len (arr1);
291 len2 = array_len (arr2);
293 result = (char **)xmalloc ((1 + (len1 * len2)) * sizeof (char *));
296 for (i = 0; i < len1; i++)
298 int strlen_1 = strlen (arr1[i]);
300 for (j = 0; j < len2; j++)
303 (char *)xmalloc (1 + strlen_1 + strlen (arr2[j]));
304 strcpy (result[len], arr1[i]);
305 strcpy (result[len] + strlen_1, arr2[j]);
312 result[len] = (char *)NULL;
319 fatal_error (format, arg1, arg2)
320 char *format, *arg1, *arg2;
322 report_error (format, arg1, arg2);
326 report_error (format, arg1, arg2)
327 char *format, *arg1, *arg2;
329 fprintf (stderr, format, arg1, arg2);
330 fprintf (stderr, "\n");
342 fprintf (stderr, "brace_expand> ");
344 if ((!fgets (example, 256, stdin)) ||
345 (strncmp (example, "quit", 4) == 0))
348 if (strlen (example))
349 example[strlen (example) - 1] = '\0';
351 result = brace_expand (example);
353 for (i = 0; result[i]; i++)
354 printf ("%s\n", result[i]);
362 * compile-command: "gcc -g -Bstatic -DTEST -o brace_expand braces.c general.o"
367 #endif /* BRACE_EXPANSION */