feat: add str trim

include/tstd/string.h

@@ -72,4 +72,12 @@ void str_to_lower(char* str);
  */
 char* str_concat(const char* str1, const char* str2);
 
+/**
+ * @brief Trim leading and trailing whitespace characters from a string.
+ * @param str Null-terminated input string (must not be NULL).
+ * @return A newly allocated string with leading and trailing whitespace removed.
+ *         The caller is responsible for freeing the allocated memory.
+ */
+char* str_trim(const char* str);
+
 #endif //TSTD_STRING_H

string.c

@@ -109,4 +109,25 @@ char* str_concat(const char* str1, const char* str2) {
     memcpy(&result[len1], str2, len2);
     result[len1 + len2] = '\0';
     return result;
+}
+
+bool p_str_char_is_rubbish(char c) {
+    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+
+char* str_trim(const char* str) {
+    size_t start = 0;
+    size_t end = strlen(str) - 1;
+    while (p_str_char_is_rubbish(str[start])) {
+        start++;
+    }
+    while (p_str_char_is_rubbish(str[end])) {
+        end--;
+    }
+
+    char* new_str = malloc(sizeof(char) * (end - start + 2));
+    memcpy(new_str, &str[start], end - start + 1);
+    new_str[end-start+1] = '\0';
+
+    return new_str;
 }

test/test_main.c

@@ -102,6 +102,16 @@ int test_string_concat() {
     return 0;
 }
 
+int test_trim() {
+    char* test_str = "   Hello, test. test   ";
+    char* trimmed_str = str_trim(test_str);
+
+    assert(strcmp(trimmed_str, "Hello, test. test") == 0);
+    free(trimmed_str);
+
+    return 0;
+}
+
 int test_string_functions() {
     int result = 0;
 
@@ -112,6 +122,7 @@ int test_string_functions() {
     result += test_string_to_upper();
     result += test_string_to_lower();
     result += test_string_concat();
+    result += test_trim();
 
     return result;
 }