PHP: error_log

Parameters

message

The error message that should be logged.

message_type

Says where the error should go. The possible message types are as follows:

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.
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. This option is only available in PHP 3.
3	`message` is appended to the file `destination`. A newline is not automatically added to the end of the `message` string.

destination

The destination. Its meaning depends on the message parameter as described above.

extra_headers

The extra headers. It's used when the message parameter is set to 1. This message type uses the same internal function as mail() does.

Examples

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"); } // other ways of calling error_log(): error_log("You messed up!", 2, "127.0.0.1:7000"); error_log("You messed up!", 2, "loghost"); error_log("You messed up!", 3, "/var/tmp/my-errors.log"); ?>

User Contributed Notes
error_log

franz at fholzinger dot com
20-Apr-2005 11:21


In the case of missing your entries in the error_log file:

When you use error_log in a script that does not produce any output, which means that you cannot see anything during the execution of the script, and when you wonder why there are no error_log entries produced in your error_log file, the reasons can be:

- you did not configure error_log output in php.ini

- the script has a syntax error and did therefore not execute

28-Mar-2003 04:14


when using error_log to send email, not all elements of an extra_headers string are handled the same way.  "From: " and "Reply-To: " header values will replace the default header values. "Subject: " header values won't: they are *added* to the mail header but don't replace the default, leading to mail messages with two Subject fields.



<?php



error_log("sometext", 1, "zigzag@my.domain", 

  "Subject: Foo\nFrom: Rizzlas@my.domain\n");



?>



---------------%<-----------------------

To: zigzag@my.domain

Envelope-to: zigzag@my.domain

Date: Fri, 28 Mar 2003 13:29:02 -0500

From: Rizzlas@my.domain

Subject: PHP error_log message

Subject: Foo

Delivery-date: Fri, 28 Mar 2003 13:29:03 -0500



sometext

---------------%<---------------------



quoth the docs: "This message type uses the same internal function as mail() does."  



mail() will also fail to set a Subject field based on extra_header data - instead it takes a seperate argument to specify a "Subject: " string.



php v.4.2.3, SunOS 5.8

dan at mojavelinux dot com
01-Feb-2003 01:46


I find it very suprising that there are no PHP constants (or references to them if they exist) for the log types.  I would expect



SYSTEM_LOG = 0

TCP_LOG = 1

FILE_LOG = 2

MAIL_LOG = 3



or something to that nature.  Are we going to see this in any future versions?  Seems very silly to use integers here when they could easily be changed or confused.

error_log

Description

Parameters

Examples