smart case search in file search

backend.c

@@ -1,3 +1,6 @@
+#include <stdlib.h>
+#include <string.h>
+
 char* concat(const char *s1, const char *s2){
     const size_t len1 = strlen(s1);
     const size_t len2 = strlen(s2);
@@ -6,5 +9,46 @@ char* concat(const char *s1, const char *s2){
     memcpy(result + len1, s2, len2 + 1);
     return result;
 }
+char* smartstrcasestr(char *haystack, const char *needle){
+	char smart = 0;
+	char *ret;
+	char passes = 0;
+	while (*needle) {
+		if (*needle >= 'A' && *needle <= 'Z') {
+			smart = 1;
+			break;
+		}
+		passes++;
+		needle++;
+	}
+	needle -= passes;
+	if (smart == 0) {
+		char *needle_case = malloc(strlen(needle)+1);
+		strcpy(needle_case, needle);
+		passes = 0;
+		while (*needle_case) {
+			*needle_case = *needle_case | ' ';
+			needle_case++;
+			passes++;
+		}
+		needle_case -= passes;
 
+		char *haystack_case = malloc(strlen(haystack)+1);
+		strcpy(haystack_case, haystack);
+		passes = 0;
+		while (*haystack_case) {
+			*haystack_case = *haystack_case | ' ';
+			haystack_case++;
+			passes++;
+		}
+		haystack_case -= passes;
+
+		ret = strstr(haystack_case, needle_case);
+		free(needle_case);
+		free(haystack_case);
+	} else {
+		ret = strstr(haystack, needle);
+	}
+	return ret;
+}