How to configure syslog so that an applications log goes to a specific file

Question

I have an application myapp which should send log files only to /var/log/myapp.log. myapp is written in C++. The following sample code, sends the logs to /var/log/syslog only. My os is Linux - Ubuntu 12.04 - to be specific. I also found that my machine has rsyslog than syslog installed.

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

int main(void) {
    openlog("myapp", LOG_PID|LOG_CONS, LOG_USER);
    syslog(LOG_INFO, "abc 10");
    closelog();
    return 0;
}

Answer 1

According to the syslog(3) manpage, the first parameter for openlog() sets a prefix for log messages, not a filename. You can use a facility like LOG_LOCAL0 to flag your output and then configure syslogd using /etc/syslog.conf to send those logs to the file of your desire.