lib/string: introduce match_string() helper
Occasionally we have to search for an occurrence of a string in an array
of strings. Make a simple helper for that purpose.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/string.c b/lib/string.c
index 0323c0d..e9c9db1 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -631,6 +631,32 @@
EXPORT_SYMBOL(sysfs_streq);
/**
+ * match_string - matches given string in an array
+ * @array: array of strings
+ * @n: number of strings in the array or -1 for NULL terminated arrays
+ * @string: string to match with
+ *
+ * Return:
+ * index of a @string in the @array if matches, or %-EINVAL otherwise.
+ */
+int match_string(const char * const *array, size_t n, const char *string)
+{
+ int index;
+ const char *item;
+
+ for (index = 0; index < n; index++) {
+ item = array[index];
+ if (!item)
+ break;
+ if (!strcmp(item, string))
+ return index;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(match_string);
+
+/**
* strtobool - convert common user inputs into boolean values
* @s: input string
* @res: result