setlogmask(3) - Linux man page
Name
setlogmask - set log priority maskSynopsis
#include <syslog.h> int setlogmask(int mask);
Description
The setlogmask() function sets this logmask for the calling process, and returns the previous mask. If the mask argument is 0, the current logmask is not modified.
The eight priorities are LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, and LOG_DEBUG. The bit corresponding to a priority p is LOG_MASK(p). Some systems also provide a macro LOG_UPTO(p) for the mask of all priorities in the above list up to and including p.