int error_log ( string message [, int message_type [, string destination [, string extra_headers]]])
Sends an error message to the web server's error log, a
TCP port or to a file. The first parameter,
message, is the error message that should be
logged. The second parameter, message_type says
where the message should go:
Table 1. error_log() log types
0
message is sent to PHP's system logger, using
the Operating System's system logging mechanism or a file, depending
on what the error_log
configuration directive is set to. This is the default option.
1
message is sent by email to the address in
the destination parameter. This is the only
message type where the fourth parameter,
extra_headers is used. This message type
uses the same internal function as mail() does.
2
message is sent through the PHP debugging
connection. This option is only available if remote debugging has
been enabled. In this case, the
destination parameter specifies the host name
or IP address and optionally, port number, of the socket receiving
the debug information.
3
message is appended to the file
destination.
Note:
When explicitly specifying the message_type as
3, a newline is not automatically added to the end of
the message string.
Warning
Remote debugging via TCP/IP is a PHP 3 feature that is
not available in PHP 4.
Example 1. error_log() examples
<?php // Send notification through the server log if we can not
// connect to the database. if (!Ora_Logon($username, $password)) { error_log("Oracle database not available!", 0);
}
// Notify administrator by email if we run out of FOO if (!($foo = allocate_new_foo())) { error_log("Big trouble, we're all out of FOOs!", 1, "operator@example.com");
}
