[utils] string_is_lower/string_is_upper method

src/string_utils.c

@@ -76,10 +76,24 @@ void string_upper(char *s) {
     for (; *s; ++s) *s = toupper(*s);
 }
 
+bool string_is_upper(char *s) {
+    for (; *s; ++s) {
+        if (*s != toupper(*s)) return false;
+    }
+    return true;
+}
+
 void string_lower(char *s) {
     for (; *s; ++s) *s = tolower(*s);
 }
 
+bool string_is_lower(char *s) {
+    for (; *s; ++s) {
+        if (*s != tolower(*s)) return false;
+    }
+    return true;
+}
+
 uint string_translate(char *str, size_t len, char *word_chars, char *word_repls, size_t trans_len) {
     uint num_replacements = 0;