优化

2026-07-09 09:57:00 +08:00
parent 241096d805
commit e27272c36d
3 changed files with 62 additions and 2 deletions
@@ -0,0 +1,33 @@
+#include <str_util.h>
+
+
+const char* str_util_strnstr(const char* haystack, const char* needle, os_size_t needle_len) {
+    if (needle_len == 0) return (char*)haystack;
+    if (!haystack || !needle || haystack[0]=='\0') return NULL;
+
+    os_size_t haystack_len = strlen(haystack);
+    if (haystack_len < needle_len) return NULL;
+
+    for (os_size_t i = 0; i <= haystack_len - needle_len; i++) {
+        if (memcmp(haystack + i, needle, needle_len) == 0) {
+            return haystack + i;
+        }
+    }
+    return NULL;
+}
+
+const char* str_util_strstr(const char* haystack, const char* needle) {
+    if (!haystack || !needle || haystack[0]=='\0' || needle[0]=='\0') return NULL;
+
+    os_size_t needle_len = strlen(needle);
+    os_size_t haystack_len = strlen(haystack);
+    if (haystack_len < needle_len) return NULL;
+
+    for (os_size_t i = 0; i <= haystack_len - needle_len; i++) {
+        if (memcmp(haystack + i, needle, needle_len) == 0) {
+            return haystack + i;
+        }
+    }
+    return NULL;
+}
+