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authorDu, Changbin <changbin.du@gmail.com>2014-01-23 15:54:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:55 -0800
commitaace05097a0fd467230e39acb148be0fdaa90068 (patch)
treeca2e61621bcb24ad83f3f145987c8ffd5c28c65b
parent0d9dfc23f4d8c17365c84eb48ecca28b963ba192 (diff)
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>
-rw-r--r--include/linux/parser.h1
-rw-r--r--lib/parser.c51
2 files changed, 52 insertions, 0 deletions
diff --git a/include/linux/parser.h b/include/linux/parser.h
index ea2281e726f6..39d5b7955b23 100644
--- a/include/linux/parser.h
+++ b/include/linux/parser.h
@@ -29,5 +29,6 @@ int match_token(char *, const match_table_t table, substring_t args[]);
int match_int(substring_t *, int *result);
int match_octal(substring_t *, int *result);
int match_hex(substring_t *, int *result);
+bool match_wildcard(const char *pattern, const char *str);
size_t match_strlcpy(char *, const substring_t *, size_t);
char *match_strdup(const substring_t *);
diff --git a/lib/parser.c b/lib/parser.c
index 807b2aaa33fa..ee5295541cea 100644
--- a/lib/parser.c
+++ b/lib/parser.c
@@ -193,6 +193,56 @@ int match_hex(substring_t *s, int *result)
}
/**
+ * 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_token);
EXPORT_SYMBOL(match_int);
EXPORT_SYMBOL(match_octal);
EXPORT_SYMBOL(match_hex);
+EXPORT_SYMBOL(match_wildcard);
EXPORT_SYMBOL(match_strlcpy);
EXPORT_SYMBOL(match_strdup);