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-rw-r--r--lib/string.c61
1 files changed, 41 insertions, 20 deletions
diff --git a/lib/string.c b/lib/string.c
index 9f75b4ec50b8..f71bead1be3e 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -36,25 +36,21 @@ int strnicmp(const char *s1, const char *s2, size_t len)
/* Yes, Virginia, it had better be unsigned */
unsigned char c1, c2;
- c1 = c2 = 0;
- if (len) {
- do {
- c1 = *s1;
- c2 = *s2;
- s1++;
- s2++;
- if (!c1)
- break;
- if (!c2)
- break;
- if (c1 == c2)
- continue;
- c1 = tolower(c1);
- c2 = tolower(c2);
- if (c1 != c2)
- break;
- } while (--len);
- }
+ if (!len)
+ return 0;
+
+ do {
+ c1 = *s1++;
+ c2 = *s2++;
+ if (!c1 || !c2)
+ break;
+ if (c1 == c2)
+ continue;
+ c1 = tolower(c1);
+ c2 = tolower(c2);
+ if (c1 != c2)
+ break;
+ } while (--len);
return (int)c1 - (int)c2;
}
EXPORT_SYMBOL(strnicmp);
@@ -667,7 +663,7 @@ EXPORT_SYMBOL(memscan);
*/
char *strstr(const char *s1, const char *s2)
{
- int l1, l2;
+ size_t l1, l2;
l2 = strlen(s2);
if (!l2)
@@ -684,6 +680,31 @@ char *strstr(const char *s1, const char *s2)
EXPORT_SYMBOL(strstr);
#endif
+#ifndef __HAVE_ARCH_STRNSTR
+/**
+ * strnstr - Find the first substring in a length-limited string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ * @len: the maximum number of characters to search
+ */
+char *strnstr(const char *s1, const char *s2, size_t len)
+{
+ size_t l2;
+
+ l2 = strlen(s2);
+ if (!l2)
+ return (char *)s1;
+ while (len >= l2) {
+ len--;
+ if (!memcmp(s1, s2, l2))
+ return (char *)s1;
+ s1++;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(strnstr);
+#endif
+
#ifndef __HAVE_ARCH_MEMCHR
/**
* memchr - Find a character in an area of memory.