lib/parser.c: add match_wildcard() function
match_wildcard function is a simple implementation of wildcard
matching algorithm. It only supports two usual wildcardes:
'*' - matches zero or more characters
'?' - matches one character
This algorithm is safe since it is non-recursive.
Signed-off-by: Du, Changbin <changbin.du@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/parser.c b/lib/parser.c
index 807b2aa..ee52955 100644
--- a/lib/parser.c
+++ b/lib/parser.c
@@ -193,6 +193,56 @@
}
/**
+ * match_wildcard: - parse if a string matches given wildcard pattern
+ * @pattern: wildcard pattern
+ * @str: the string to be parsed
+ *
+ * Description: Parse the string @str to check if matches wildcard
+ * pattern @pattern. The pattern may contain two type wildcardes:
+ * '*' - matches zero or more characters
+ * '?' - matches one character
+ * If it's matched, return true, else return false.
+ */
+bool match_wildcard(const char *pattern, const char *str)
+{
+ const char *s = str;
+ const char *p = pattern;
+ bool star = false;
+
+ while (*s) {
+ switch (*p) {
+ case '?':
+ s++;
+ p++;
+ break;
+ case '*':
+ star = true;
+ str = s;
+ if (!*++p)
+ return true;
+ pattern = p;
+ break;
+ default:
+ if (*s == *p) {
+ s++;
+ p++;
+ } else {
+ if (!star)
+ return false;
+ str++;
+ s = str;
+ p = pattern;
+ }
+ break;
+ }
+ }
+
+ if (*p == '*')
+ ++p;
+ return !*p;
+}
+
+/**
* match_strlcpy: - Copy the characters from a substring_t to a sized buffer
* @dest: where to copy to
* @src: &substring_t to copy
@@ -235,5 +285,6 @@
EXPORT_SYMBOL(match_int);
EXPORT_SYMBOL(match_octal);
EXPORT_SYMBOL(match_hex);
+EXPORT_SYMBOL(match_wildcard);
EXPORT_SYMBOL(match_strlcpy);
EXPORT_SYMBOL(match_strdup);