[linux-yocto] [PATCH 6/8] lib/string: introduce match_string() helper

[wan.ahmad.zainie.wan.mohamad at intel.com]

From: Andy Shevchenko <andriy.shevchenko at linux.intel.com>

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 at linux.intel.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Cc: David Airlie <airlied at linux.ie>
Cc: David Woodhouse <dwmw2 at infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus at linux.intel.com>
Cc: Linus Walleij <linus.walleij at linaro.org>
Cc: Mika Westerberg <mika.westerberg at linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Cc: Sebastian Reichel <sre at kernel.org>
Cc: Tejun Heo <tj at kernel.org>
Cc: Rasmus Villemoes <linux at rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
(cherry picked from commit 56b060814e2d87d6646a85a2f4609c73587399ca)
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad at intel.com>
---
 include/linux/string.h |  2 ++
 lib/string.c           | 26 ++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h
index e40099e..dbbdb65 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -125,6 +125,8 @@ extern void argv_free(char **argv);
 extern bool sysfs_streq(const char *s1, const char *s2);
 extern int strtobool(const char *s, bool *res);
 
+int match_string(const char * const *array, size_t n, const char *string);
+
 #ifdef CONFIG_BINARY_PRINTF
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
diff --git a/lib/string.c b/lib/string.c
index bb3d4b6..f056a51 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -542,6 +542,32 @@ bool sysfs_streq(const char *s1, const char *s2)
 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
-- 
1.9.1