/c-minimal-logger

Primary LanguageCMIT LicenseMIT

minimal logger for c

Usage

// example.c
#include "logger.h"

int main(void) {
  LOG_DEBUG("debug");
  LOG_INFO("hello %s!", "John");
  LOG_ERROR("failed %d tests", 100);
  return 0;
}
$ ./example
2015-11-08 18:22:53 [INFO] hello John! at example.c line 5
2015-11-08 18:22:53 [ERROR] failed 100 tests at example.c line 6

$ LOG_DEBUG=1 ./example
2015-11-08 18:23:36 [DEBUG] debug at example.c line 4
2015-11-08 18:23:36 [INFO] hello John! at example.c line 5
2015-11-08 18:23:36 [ERROR] failed 100 tests at example.c line 6

Available macros

  • LOG_DEBUG(const char* fmt, ...) (prints only if LOG_DEBUG=1)
  • LOG_INFO(const char* fmt, ...)
  • LOG_WARN(const char* fmt, ...)
  • LOG_ERROR(const char* fmt, ...)

Customize

change LOG_DEBUG environment variable

$ gcc -DLOG_DEBUG_ENV_NAME=\"MY_DEBUG\" -o example example.c
$ MY_DEBUG=1 ./example

prints pid

$ gcc -DLOG_PRINT_PID -o example example.c
$ ./example
2015-11-08 18:58:28 [INFO][pid 62242] hello John! at example.c line 5

Author

Shoichi Kaji