5b2db9770
Denys Vlasenko
2009-11-16
Subject
hush: initial stab at brace expansion support
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shell/hush.c+133 -4
| @@ -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]) { | |