Added strstr

include/sv.h

@@ -26,6 +26,7 @@ extern struct String_View sv_before_delim(const struct String_View sv,
         const char *delims);
 extern struct String_View sv_after_delim(const struct String_View sv,
         const char *delims);
-
+extern struct String_View sv_str_str(const struct String_View haystack, 
+        const struct String_View needle);
 
 #endif

src/sv.c

@@ -80,7 +80,6 @@ struct String_View sv_before_delim(const struct String_View sv,const char *delim
     return result;
 
 }
-
 struct String_View sv_after_delim(const struct String_View sv, const char *delims){
     // Handle NULL pointer or empty string view
     if (sv.buf == NULL || delims == NULL) {
@@ -103,3 +102,16 @@ struct String_View sv_after_delim(const struct String_View sv, const char *delim
     struct String_View result = sv_strn(sv.buf, i);
     return result;
 }
+
+struct String_View sv_str_str(const struct String_View haystack, const struct String_View needle){
+    size_t i;
+    if (needle.len > haystack.len) return sv_strn(NULL,0);
+    if (needle.len == 0) return haystack;
+    for (i = 0; i <= haystack.len - needle.len; i++) {
+        if (memcmp(haystack.buf + i, needle.buf, needle.len) == 0) {
+            return sv_strn(haystack.buf + i, haystack.len -i);
+        }
+    }
+    return sv_strn(NULL,0);
+}
+

tests/10_strstr.c

@@ -0,0 +1,20 @@
+#define DEBUG
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include "../include/sv.h"
+
+int main(void){
+    const char *s = "Hello World!,Goodbye World!";
+    const char *n = "Goodbye";
+    const char *test = "Goodbye World!";   
+    struct String_View sv = sv_strn(s, strlen(s));
+    struct String_View sv2 = sv_strn(n, strlen(n));
+
+    struct String_View found = sv_str_str(sv, sv2);
+    assert(found.len == strlen(test));
+    assert( memcmp(found.buf, test, found.len) == 0);
+
+    return EXIT_SUCCESS;
+}