Logging for C program

Question

I need some clever logging library for a daemon-like C (not C++) program on Linux. It needs to be open-source. It should support logging to files, maybe sockets etc.

Or at least some good tips or tricks or best practices.

Answer 1

the following is something that you could do .

I am assuming your C application runs as a deamon and hence you cannot frintf the logging messages . syslog() is certainly an option for routing you messages . syslog() is very option the location where deamons write their messages and the adminstrators parse the contents of the syslog file to reach meaningful conclusions . Also syslog has a particual logging format . However i wish the propose that you write your own logging scheme . It is often what is desireable in enterprise software and not logging into syslog . Do this

1 . in you main configuration file define a logging macro

 #define LOG_ERR log_err 

having a definition like log_err(int errno,char *logger , char *text) the api should log details to a log file .

1. any c file which includes the main configuration file can just use the macro

   LOG_ERR(errno,"handle_submission()","Submission of job failed ")

You should also include time stamps in the logger file .

Answer 2

Use syslog() . This decouples your in program logging from how the logs are handled. rsyslog is used on most Linux distributions nowadays, and allows great flexibility on how the logs are processed.