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authorDenys Vlasenko <vda.linux@googlemail.com>2009-11-16 04:49:36 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2009-11-16 04:49:36 (GMT)
commit5b2db97703630885b8f4c1ce0371415d1d2501a9 (patch)
tree59bf827229f0f52b63f7f10ffd3e105a09de41de
parentd8389ad76028a536d1869ec163c15fd817dc7b65 (diff)
downloadbusybox-5b2db97703630885b8f4c1ce0371415d1d2501a9.tar.gz
busybox-5b2db97703630885b8f4c1ce0371415d1d2501a9.tar.bz2
hush: initial stab at brace expansion support
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--shell/hush.c137
1 files changed, 133 insertions, 4 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 235cee9..171b739 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2003,6 +2003,130 @@ static int o_get_last_ptr(o_string *o, int n)
return ((int)(ptrdiff_t)list[n-1]) + string_start;
}
+#undef HUSH_BRACE_EXP
+/* There in a GNU extension, GLOB_BRACE, but it is not usable:
+ * first, it processes even {a} (no commas), second,
+ * I didn't manage to make it return strings when they don't match
+ # existing files. Need to re-implement it.
+ *
+ * This code needs corresponding quoting on variable expansion side.
+ * Currently, "a='{q,w}'; echo $a" erroneously expands braces in $a
+ */
+#ifdef HUSH_BRACE_EXP
+/* Return pointer to next closing brace or to comma */
+static const char *next_brace_sub(const char *cp)
+{
+ unsigned depth = 0;
+ cp++;
+ while (*cp != '\0') {
+ if (*cp == '\\') {
+ if (*++cp == '\0')
+ break;
+ cp++;
+ continue;
+ }
+ /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
+ break;
+ if (*cp++ == '{') /*}*/
+ depth++;
+ }
+
+ return *cp != '\0' ? cp : NULL;
+}
+static int glob_brace(const char *pattern, int flags, glob_t *pglob)
+{
+ const char *begin;
+ char *alt_start;
+ const char *p;
+ const char *next;
+ const char *rest;
+ size_t rest_len;
+ char *onealt;
+
+ debug_printf_glob("glob_brace('%s')\n", pattern);
+
+ begin = pattern;
+ while (1) {
+ if (*begin == '\0')
+ goto do_glob;
+ if (*begin == '{') /*}*/ {
+ /* Find the first sub-pattern and at the same time
+ * find the rest after the closing brace */
+ next = next_brace_sub(begin);
+ if (next == NULL) {
+ /* An illegal expression */
+ goto do_glob;
+ }
+ /*{*/ if (*next == '}') {
+ /* "{abc}" with no commas - illegal
+ * brace expr, disregard and skip it */
+ begin = next + 1;
+ continue;
+ }
+ break;
+ }
+ if (*begin == '\\' && begin[1] != '\0')
+ begin++;
+ begin++;
+ }
+ debug_printf_glob("begin:%s\n", begin);
+ debug_printf_glob("next:%s\n", next);
+
+ /* Now find the end of the whole brace expression */
+ rest = next;
+ /*{*/ while (*rest != '}') {
+ rest = next_brace_sub(rest);
+ if (rest == NULL) {
+ /* An illegal expression */
+ goto do_glob;
+ }
+ debug_printf_glob("rest:%s\n", rest);
+ }
+ rest_len = strlen(++rest) + 1;
+
+ /* We are sure the brace expression is well-formed */
+
+ /* Allocate working buffer large enough for our work */
+ onealt = alloca(strlen(pattern));
+ /* We know the prefix for all sub-patterns */
+ alt_start = mempcpy(onealt, pattern, begin - pattern);
+
+ /* We have a brace expression. BEGIN points to the opening {,
+ * NEXT points past the terminator of the first element, and REST
+ * points past the final }. We will accumulate result names from
+ * recursive runs for each brace alternative in the buffer using
+ * GLOB_APPEND. */
+
+ p = begin + 1;
+ while (1) {
+ int result;
+
+ /* Construct the new glob expression */
+ memcpy(mempcpy(alt_start, p, next - p), rest, rest_len);
+
+ result = glob_brace(onealt, flags, pglob);
+ /* If we got an error, return it */
+ if (result && result != GLOB_NOMATCH)
+ return result;
+
+ flags |= GLOB_APPEND;
+
+ /*{*/ if (*next == '}') {
+ /* We saw the last entry */
+ break;
+ }
+ p = next + 1;
+ next = next_brace_sub(next);
+ }
+
+ /* We found some entries */
+ return 0;
+
+ do_glob:
+ return glob(pattern, flags, NULL, pglob);
+}
+#endif
+
/* o_glob performs globbing on last list[], saving each result
* as a new list[]. */
static int o_glob(o_string *o, int n)
@@ -2024,17 +2148,22 @@ static int o_glob(o_string *o, int n)
}
memset(&globdata, 0, sizeof(globdata));
-//TODO: can use GLOB_BRACE | GLOB_TILDE here:
+#ifdef HUSH_BRACE_EXP
+ gr = glob_brace(pattern, GLOB_NOCHECK, &globdata);
+ debug_printf_glob("glob_brace('%s'):%d\n", pattern, gr);
+#else
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
+#endif
if (gr == GLOB_NOSPACE)
- bb_error_msg_and_die("out of memory during glob");
+ bb_error_msg_and_die(bb_msg_memory_exhausted);
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
- if (gr != 0) { /* GLOB_ABORTED ? */
- /* TODO: testcase for bad glob pattern behavior */
+ if (gr != 0) {
+ /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
+ * but we didn't specify it. Paranoia again. */
bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {