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 after variable and command
22 substitution, but before filename globbing.
24 (Actually, this should be true for the sake of efficiency, but it
25 isn't because of quoting hacks. Once I rebuild quoting it will be
28 #if defined (HAVE_STRING_H)
30 #else /* !HAVE_STRING_H */
32 #endif /* !HAVE_STRING_H */
39 #define brace_whitespace(c) (!(c) || (c) == ' ' || (c) == '\t' || (c) == '\n')
43 Segregate the text into 3 sections: preamble (stuff before an open brace),
44 postamble (stuff after the matching close brace) and amble (stuff after
45 preamble, and before postamble). Expand amble, and then tack on the
46 expansions to preamble. Expand postamble, and tack on the expansions to
50 /* The character which is used to separate arguments. */
51 int brace_arg_separator = ',';
53 static int brace_gobbler ();
54 static char **expand_amble (), **array_concat ();
56 /* Return an array of strings; the brace expansion of TEXT. */
62 char *preamble, *postamble, *amble;
63 char **tack, **result;
66 /* Find the text of the preamble. */
68 c = brace_gobbler (text, &i, '{');
70 preamble = (char *)xmalloc (i + 1);
71 strncpy (preamble, text, i);
74 result = (char **)xmalloc (2 * sizeof (char *));
76 result[1] = (char *)NULL;
78 /* Special case. If we never found an exciting character, then
79 the preamble is all of the text, so just return that. */
83 /* Find the amble. This is the stuff inside this set of braces. */
85 c = brace_gobbler (text, &i, '}');
87 /* What if there isn't a matching close brace? */
93 /* Well, if we found an unquoted BRACE_ARG_SEPARATOR between START
94 and I, then this should be an error. Otherwise, it isn't. */
95 for (j = start; j < i; j++)
103 if (text[j] == brace_arg_separator)
106 report_error ("Missing `}'");
107 throw_to_top_level ();
111 free (preamble); /* Same as result[0]; see initialization. */
112 result[0] = savestring (text);
116 amble = (char *)xmalloc (1 + (i - start));
117 strncpy (amble, &text[start], (i - start));
118 amble[i - start] = '\0';
121 /* If the amble does not contain an unquoted BRACE_ARG_SEPARATOR, then
122 just return without doing any expansion. */
126 for (j = 0; amble[j]; j++)
128 if (amble[j] == '\\')
133 if (amble[j] == brace_arg_separator)
141 result[0] = savestring (text);
147 postamble = &text[i + 1];
149 tack = expand_amble (amble);
150 result = array_concat (result, tack);
154 tack = brace_expand (postamble);
155 result = array_concat (result, tack);
161 /* Expand the text found inside of braces. We simply try to split the
162 text at BRACE_ARG_SEPARATORs into separate strings. We then brace
163 expand each slot which needs it, until there are no more slots which
169 char **result, **partial;
173 result = (char **)NULL;
175 for (start = 0, i = 0, c = 1; c; start = ++i)
177 c = brace_gobbler (text, &i, brace_arg_separator);
178 tem = (char *)xmalloc (1 + (i - start));
179 strncpy (tem, &text[start], (i - start));
180 tem[i- start] = '\0';
182 partial = brace_expand (tem);
188 register int lr = array_len (result);
189 register int lp = array_len (partial);
192 result = (char **)xrealloc (result, (1 + lp + lr) * sizeof (char *));
194 for (j = 0; j < lp; j++)
195 result[lr + j] = partial[j];
197 result[lr + j] = (char *)NULL;
205 /* Start at INDEX, and skip characters in TEXT. Set INDEX to the
206 index of the character matching SATISFY. This understands about
207 quoting. Return the character that caused us to stop searching;
208 this is either the same as SATISFY, or 0. */
210 brace_gobbler (text, indx, satisfy)
215 register int i, c, quoted, level, pass_next;
217 level = quoted = pass_next = 0;
219 for (i = *indx; c = text[i]; i++)
227 /* A backslash escapes the next character. This allows backslash to
228 escape the quote character in a double-quoted string. */
229 if (c == '\\' && (quoted == 0 || quoted == '"' || quoted == '`'))
242 if (c == '"' || c == '\'' || c == '`')
248 if (c == satisfy && !level && !quoted)
250 /* We ignore an open brace surrounded by whitespace, and also
251 an open brace followed immediately by a close brace, that
252 was preceded with whitespace. */
254 ((!i || brace_whitespace (text[i - 1])) &&
255 (brace_whitespace (text[i + 1]) || text[i + 1] == '}')))
258 /* If this is being compiled as part of bash, ignore the `{'
259 in a `${}' construct */
260 if ((c != '{') || !i || (text[i - 1] != '$'))
262 if ((c != '{') || !i)
269 else if (c == '}' && level)
277 /* Return a new array of strings which is the result of appending each
278 string in ARR2 to each string in ARR1. The resultant array is
279 len (arr1) * len (arr2) long. For convenience, ARR1 (and its contents)
280 are free ()'ed. ARR1 can be NULL, in that case, a new version of ARR2
283 array_concat (arr1, arr2)
286 register int i, j, len, len1, len2;
287 register char **result;
290 return (copy_array (arr2));
293 return (copy_array (arr1));
295 len1 = array_len (arr1);
296 len2 = array_len (arr2);
298 result = (char **)xmalloc ((1 + (len1 * len2)) * sizeof (char *));
301 for (i = 0; i < len1; i++)
303 int strlen_1 = strlen (arr1[i]);
305 for (j = 0; j < len2; j++)
308 (char *)xmalloc (1 + strlen_1 + strlen (arr2[j]));
309 strcpy (result[len], arr1[i]);
310 strcpy (result[len] + strlen_1, arr2[j]);
317 result[len] = (char *)NULL;
324 fatal_error (format, arg1, arg2)
325 char *format, *arg1, *arg2;
327 report_error (format, arg1, arg2);
331 report_error (format, arg1, arg2)
332 char *format, *arg1, *arg2;
334 fprintf (stderr, format, arg1, arg2);
335 fprintf (stderr, "\n");
347 fprintf (stderr, "brace_expand> ");
349 if ((!fgets (example, 256, stdin)) ||
350 (strncmp (example, "quit", 4) == 0))
353 if (strlen (example))
354 example[strlen (example) - 1] = '\0';
356 result = brace_expand (example);
358 for (i = 0; result[i]; i++)
359 printf ("%s\n", result[i]);
367 * compile-command: "gcc -g -Bstatic -DTEST -o brace_expand braces.c general.o"