Bump to version 1.22.1

[platform/upstream/busybox.git] / shell / match.c

diff --git a/shell/match.c b/shell/match.c
index 8b1ddac..fee3cf2 100644 (file)
--- a/shell/match.c
+++ b/shell/match.c
@@ -18,65 +18,78 @@
 # include <stdlib.h>
 # include <string.h>
 # include <unistd.h>
+# define FAST_FUNC /* nothing */
+# define PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN /* nothing */
+# define POP_SAVED_FUNCTION_VISIBILITY /* nothing */
 #else
 # include "libbb.h"
 #endif
 #include <fnmatch.h>
 #include "match.h"
 
-#define pmatch(a, b) !fnmatch((a), (b), 0)
-
-char *scanleft(char *string, char *pattern, bool match_at_left)
+char* FAST_FUNC scan_and_match(char *string, const char *pattern, unsigned flags)
 {
-       char c;
-       char *loc = string;
-
-       do {
-               int match;
-               const char *s;
-
-               c = *loc;
-               if (match_at_left) {
-                       *loc = '\0';
-                       s = string;
-               } else
-                       s = loc;
-               match = pmatch(pattern, s);
-               *loc = c;
-
-               if (match)
-                       return loc;
-
-               loc++;
-       } while (c);
-
-       return NULL;
-}
-
-char *scanright(char *string, char *pattern, bool match_at_left)
-{
-       char c;
-       char *loc = string + strlen(string);
+       char *loc;
+       char *end;
+       unsigned len = strlen(string);
+       int early_exit;
+
+       /* We can stop the scan early only if the string part
+        * we are matching against is shrinking, and the pattern has
+        * an unquoted "star" at the corresponding end. There are two cases.
+        * Case 1:
+        * "qwerty" does not match against pattern "*zy",
+        * no point in trying to match "werty", "erty" etc:
+        */
+       early_exit = (flags == (SCAN_MOVE_FROM_LEFT + SCAN_MATCH_RIGHT_HALF) && pattern[0] == '*');
+
+       if (flags & SCAN_MOVE_FROM_LEFT) {
+               loc = string;
+               end = string + len + 1;
+       } else {
+               loc = string + len;
+               end = string - 1;
+               if (flags == (SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF)) {
+                       /* Case 2:
+                        * "qwerty" does not match against pattern "qz*",
+                        * no point in trying to match "qwert", "qwer" etc:
+                        */
+                       const char *p = pattern + strlen(pattern);
+                       if (--p >= pattern && *p == '*') {
+                               early_exit = 1;
+                               while (--p >= pattern && *p == '\\')
+                                       early_exit ^= 1;
+                       }
+               }
+       }
 
-       while (loc >= string) {
-               int match;
-               const char *s;
+       while (loc != end) {
+               char c;
+               int r;
 
                c = *loc;
-               if (match_at_left) {
+               if (flags & SCAN_MATCH_LEFT_HALF) {
                        *loc = '\0';
-                       s = string;
-               } else
-                       s = loc;
-               match = pmatch(pattern, s);
-               *loc = c;
-
-               if (match)
+                       r = fnmatch(pattern, string, 0);
+                       *loc = c;
+               } else {
+                       r = fnmatch(pattern, loc, 0);
+               }
+               if (r == 0) /* match found */
                        return loc;
+               if (early_exit) {
+#ifdef STANDALONE
+                       printf("(early exit) ");
+#endif
+                       break;
+               }
 
-               loc--;
+               if (flags & SCAN_MOVE_FROM_LEFT) {
+                       loc++;
+               } else {
+                       loc--;
+               }
        }
-
        return NULL;
 }
 
@@ -86,12 +99,11 @@ int main(int argc, char *argv[])
        char *string;
        char *op;
        char *pattern;
-       bool match_at_left;
        char *loc;
 
-       int i;
+       setvbuf(stdout, NULL, _IONBF, 0);
 
-       if (argc == 1) {
+       if (!argv[1]) {
                puts(
                        "Usage: match <test> [test...]\n\n"
                        "Where a <test> is the form: <string><op><match>\n"
@@ -101,36 +113,34 @@ int main(int argc, char *argv[])
                return 1;
        }
 
-       for (i = 1; i < argc; ++i) {
+       while (*++argv) {
                size_t off;
-               scan_t scan;
-
-               printf("'%s': ", argv[i]);
+               unsigned scan_flags;
 
-               string = strdup(argv[i]);
+               string = *argv;
                off = strcspn(string, "#%");
                if (!off) {
                        printf("invalid format\n");
-                       free(string);
                        continue;
                }
                op = string + off;
-               scan = pick_scan(op[0], op[1], &match_at_left);
+               scan_flags = pick_scan(op[0], op[1]);
+
+               printf("'%s': flags:%x, ", string, scan_flags);
                pattern = op + 1;
                if (op[0] == op[1])
-                       op[1] = '\0', ++pattern;
+                       pattern++;
                op[0] = '\0';
 
-               loc = scan(string, pattern, match_at_left);
+               loc = scan_and_match(string, pattern, scan_flags);
 
-               if (match_at_left) {
+               if (scan_flags & SCAN_MATCH_LEFT_HALF) {
                        printf("'%s'\n", loc);
                } else {
-                       *loc = '\0';
+                       if (loc)
+                               *loc = '\0';
                        printf("'%s'\n", string);
                }
-
-               free(string);
        }
 
        return 0;