(PHP 4, PHP 5)
openlog — Open connection to system logger
openlog() opens a connection to the system logger for a program.
The use of openlog() is optional. It will automatically be called by syslog() if necessary, in which case ident will default to FALSE.
The string ident is added to each message.
The option argument is used to indicate what logging options will be used when generating a log message.
| Constant | Description |
|---|---|
| LOG_CONS | if there is an error while sending data to the system logger, write directly to the system console |
| LOG_NDELAY | open the connection to the logger immediately |
| LOG_ODELAY | (default) delay opening the connection until the first message is logged |
| LOG_PERROR | print log message also to standard error |
| LOG_PID | include PID with each message |
You can use one or more of this options. When using multiple options you need to OR them, i.e. to open the connection immediately, write to the console and include the PID in each message, you will use: LOG_CONS | LOG_NDELAY | LOG_PID
The facility argument is used to specify what type of program is logging the message. This allows you to specify (in your machine's syslog configuration) how messages coming from different facilities will be handled.
| Constant | Description |
|---|---|
| LOG_AUTH | security/authorization messages (use LOG_AUTHPRIV instead in systems where that constant is defined) |
| LOG_AUTHPRIV | security/authorization messages (private) |
| LOG_CRON | clock daemon (cron and at) |
| LOG_DAEMON | other system daemons |
| LOG_KERN | kernel messages |
| LOG_LOCAL0 ... LOG_LOCAL7 | reserved for local use, these are not available in Windows |
| LOG_LPR | line printer subsystem |
| LOG_MAIL | mail subsystem |
| LOG_NEWS | USENET news subsystem |
| LOG_SYSLOG | messages generated internally by syslogd |
| LOG_USER | generic user-level messages |
| LOG_UUCP | UUCP subsystem |
Note: LOG_USER is the only valid log type under Windows operating systems
如果成功则返回 TRUE，失败则返回 FALSE。