Log with custom prefix function added

README.md

@@ -17,6 +17,7 @@ int main() {
     log_info("Some information: %d %s", 123, "fr");
     log_error("%s", "error message");
     log_debug("Debug won't be printed because the flag was not set");
+    log_with_prefix("[Custom prefix] ", "5+(4*90)==%d", 5+(4*90));
 
     // Creates file with fopen's mode and sets log output to it
     create_log_file("logs.log", "w");

src/slog.c

@@ -52,6 +52,19 @@ void close_log_file() {
     }
 }
 
+// Log a message with custom prefix. Counts as INFO log message
+void log_with_prefix(const char* prefix, const char* message, ...) {
+    if (LOG_OUTPUT && ((LOGGING_LEVEL & INFO) == INFO) && prefix && message) {
+        va_list arg;
+
+        fprintf(LOG_OUTPUT, "%s", prefix);
+        va_start(arg, message);
+        vfprintf(LOG_OUTPUT, message, arg);
+        va_end(arg);
+        fprintf(LOG_OUTPUT, "\n");
+    }
+}
+
 // Log information
 void log_info(const char* message, ...) {
     if (LOG_OUTPUT && ((LOGGING_LEVEL & INFO) == INFO) && message) {

src/slog.h

@@ -40,6 +40,9 @@ int create_log_file(const char* path, const char* mode);
 // Does nothing if log output is std(out|error|input)
 void close_log_file();
 
+// Log a message with custom prefix. Counts as INFO log message
+void log_with_prefix(const char* prefix, const char* message, ...);
+
 // Log information
 void log_info(const char* message, ...);
 

testing/test.c

@@ -13,4 +13,6 @@ int main() {
     close_log_file();
 
     log_warning("And to %s again", "stdout");
+
+    log_with_prefix("[Custom prefix] ", "5+(4*90)==%d", 5+(4*90));
 }