openlog

(PHP 4, PHP 5, PHP 7, PHP 8)

openlog — Open connection to system logger

说明

openlog(string $prefix, int $flags, int $facility): true

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 prefix will default to the empty string.

参数

prefix

The string prefix is added to each message.

flags

Bitmask of the following constants:

LOG_CONS
LOG_NDELAY
LOG_ODELAY
LOG_NOWAIT
LOG_PERROR
LOG_PID

facility

The facility argument is used to specify what type of program is logging the message. This lets the configuration file specify that messages from different facilities will be handled differently. Must be one of the following constants:

LOG_AUTH
LOG_AUTHPRIV
LOG_CRON
LOG_DAEMON
LOG_KERN
LOG_LOCAL[0-7]
LOG_LPR
LOG_MAIL
LOG_NEWS
LOG_SYSLOG
LOG_USER
LOG_UUCP

注意: This parameter is ignored on Windows.

返回值

总是返回 true。

更新日志

版本	说明
8.2.0	The function now always returns `true`. Previously it returned `false` on failure.

参见

syslog() - Generate a system log message
closelog() - 关闭系统日志链接

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Nimja ¶

11 years ago

To those curious; switching between different facilities is NOT an issue. There is no apparent memory overhead (nor slowdown) by calling openlog multiple(12 * 10000) times.

Shown by this example:

<?php
$facilities = array(
LOG_AUTH,
LOG_AUTHPRIV,
LOG_CRON,
LOG_DAEMON,
LOG_KERN,
LOG_LOCAL0,
LOG_LPR,
LOG_MAIL,
LOG_NEWS,
LOG_SYSLOG,
LOG_USER,
LOG_UUCP,
);

for ($i = 0; $i < 10000; $i++) {
    foreach ($facilities as $facility) {
openlog('test', LOG_PID, $facility);
syslog(LOG_ERR, "This is a test: " . memory_get_usage(true));
    }
}
?>