syslog blah

test.c

 /*
    A quick demo program to show Syslog facilities
 
    Send "typical" log messages to facility local0.
    Send "special" log messages to facility local3.
 
    Sample syslog-ng config extract to go with this:

# This is not a complete syslog-ng config, just additions
# needed for a quick test. If your system has a different
# syslog daemon check docs, syslog-ng syntax is special.

### Temp for syslog example

# setup log file destinations
destination d_regular { file("/var/log/local0.log"); };
destination d_special { file("/var/log/local3.log"); };

# filters so we can route facilities we care about
filter f_regular { facility(local0); };
filter f_special { facility(local3); };

# based on filters route log messages to destinations we care about
log { source(src); filter(f_regular); destination(d_regular); };
log { source(src); filter(f_special); destination(d_special); };

### End Temp for syslog example


   Running test:
    - update syslog-ng config with above
    - restart syslog-ng 
    - test syslog-ng config
      $ logger -p local0.info "Hello world! regular info ..." 
      $ logger -p local3.info "Hello world! special info ..." 
      $ tail /var/log/local0.log /var/log/local3.log
      ==> /var/log/local0.log <==
      Nov  1 22:54:26 neckbeard michael: Hello world! regular info ...
      
      ==> /var/log/local3.log <==
      Nov  1 22:54:28 neckbeard michael: Hello world! special info ...
    - build and run this short sample
      $ make test
      $ ./test
    - check logs
      $ tail /var/log/local0.log /var/log/local3.log
      ==> /var/log/local0.log <==
      Nov  1 22:54:26 neckbeard michael: Hello world! regular info ...
      Nov  1 22:55:54 neckbeard ./test[32647]: log at info to local0
      Nov  1 22:55:54 neckbeard ./test[32647]: log at warn to local0
      Nov  1 22:55:54 neckbeard ./test[32647]: log at error to local0
      
      ==> /var/log/local3.log <==
      Nov  1 22:54:28 neckbeard michael: Hello world! special info ...
      Nov  1 22:55:54 neckbeard ./test[32647]: special log message to local3
    - celebrate!
    
    References, see:
       man 3 syslog - syslog functions in linux programmers manual
       man 5 syslog-ng.conf - man page for syslog-ng
       http://tools.ietf.org/html/rfc5424 - latest syslog rfc
       
 */

#include <syslog.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
    // open "regular" log
    openlog(argv[0], LOG_PID | LOG_NDELAY, LOG_LOCAL0);
    puts("logging to 'regular' facility LOCAL0");
    syslog(LOG_INFO, "log at info to local0");
    syslog(LOG_WARNING, "log at warn to local0");
    syslog(LOG_ERR,  "log at error to local0");

    puts("logging to 'special' facility LOCAL3");
    syslog(LOG_INFO|LOG_LOCAL3, "special log message to local3");

    // close "regular" log
    closelog();
}