homework-00: Free buffer

homework-00-warmup/main.c

@@ -29,16 +29,24 @@ int main() {
 
 	printf("%s\n", PROMPT);
 
+	// Use getline for dynamic allocation
 	ssize_t chars_read = getline(&buf, &len, stdin);
 
 	errno = 0;
 	long input = strtol(buf, &end, 10);
 
-	if(errno == ERANGE || chars_read == -1 || end == &buf[0]) {
+	// Check whether a range error occured or
+	// No characters were read by getline
+	// or check that strtol didnt move a single char
+	if(errno == ERANGE || chars_read == -1 || end == buf) {
 		printf("%s\n", NOT_A_NUMBER);
 		return EXIT_FAILURE;
 	}
 
+	// getline always adds the \n to the result string
+	// If the ending char by strtol is not that newline
+	// It means the string is not a whole number
+	// (e.g. 12abc, 1.23)
 	if(*end != '\n') {
 		printf("%s\n", INVALID_NUMBER);
 		return EXIT_FAILURE;
@@ -52,5 +60,6 @@ int main() {
 	printf("%s\n", INPUT_OKAY);
 	printf("%s\n", QUOTES[input]);
 
+	free(buf);
 	return EXIT_SUCCESS;
 }