syslog(3) Library Functions Manual syslog(3) closelog, openlog, syslog, vsyslog - LIBRARY Standard C library (libc, -lc) #include void openlog(const char *ident, int option, int facility); void syslog(int priority, const char *format, ...); void closelog(void); void vsyslog(int priority, const char *format, va_list ap); glibc (. feature_test_macros(7)): vsyslog(): glibc 2.19: _DEFAULT_SOURCE glibc 2.19 : _BSD_SOURCE openlog() openlog() . , ident, , . ident NULL, ( POSIX.1-2008 , , ident NULL). option , openlog() syslog(). facility , syslog(). option facility . openlog() ; syslog() ( ident NULL). syslog() vsyslog() syslog() , syslogd(8). priority facility level ( ). facility priority, , openlog(), , openlog() , LOG_USER. -- format, printf(3) ( , format) %m, strerror(errno). . vsyslog() , syslog() , , stdarg(3). closelog() closelog() , . closelog() . option option openlog() : LOG_CONS , . LOG_NDELAY ( ). , , chroot(2) , . LOG_NOWAIT , ( GNU C , Linux ). LOG_ODELAY LOG_NDELAY; , syslog() ( , ). LOG_PERROR ( POSIX.1-2001 POSIX.1-2008) stderr. LOG_PID PID . facility facility , . - . LOG_AUTH / LOG_AUTHPRIV / (private) LOG_CRON (cron at) LOG_DAEMON LOG_FTP FTP LOG_KERN ( ) LOG_LOCAL0 LOG_LOCAL7 LOG_LPR LOG_MAIL LOG_NEWS USENET LOG_SYSLOG , syslogd(8) LOG_USER ( ) LOG_UUCP UUCP level . : LOG_EMERG LOG_ALERT LOG_CRIT LOG_ERR LOG_WARNING LOG_NOTICE , LOG_INFO LOG_DEBUG setlogmask(3). attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |openlog(), closelog() | | MT-Safe | +----------------------------+----------------------------------------------------------+--------------------------+ |syslog(), vsyslog() | | MT-Safe env locale | +----------------------------+----------------------------------------------------------+--------------------------+ syslog() openlog() closelog() POSIX.1-2008. vsyslog() None. syslog() 4.2BSD, SUSv2, POSIX.1-2001. openlog() closelog() 4.3BSD, SUSv2, POSIX.1-2001. vsyslog() 4.3BSD-Reno. POSIX.1-2001 facility LOG_USER LOG_LOCAL*. , LOG_AUTHPRIV LOG_FTP, facility UNIX. LOG_PERROR option POSIX.1-2001 POSIX.1-2008, UNIX. ident openlog() . , , syslog() . , . -- . , : syslog(priority, "%s", string); . journalctl(1), logger(1), setlogmask(3), syslog.conf(5), syslogd(8) Alexander Golubev , Azamat Hackimov , Hotellook, Nikita , Spiros Georgaras , Vladislav , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . syslog(3)