The behaviour of these functions is affected by settings in php.ini.
Prior to PHP 8.0.0, the default value was
|track_errors||"0"||PHP_INI_ALL||Deprecated as of PHP 7.2.0, removed as of PHP 8.0.0.|
|syslog.facility||"LOG_USER"||PHP_INI_SYSTEM||Available as of PHP 7.3.0.|
|syslog.filter||"no-ctrl"||PHP_INI_ALL||Available as of PHP 7.3.0.|
|syslog.ident||"php"||PHP_INI_SYSTEM||Available as of PHP 7.3.0.|
Here's a short explanation of the configuration directives.
Set the error reporting level. The parameter is either an integer representing a bit field, or named constants. The error_reporting levels and constants are described in Predefined Constants, and in php.ini. To set at runtime, use the error_reporting() function. See also the display_errors directive.
The default value is
Prior to PHP 8.0.0, the default value was:
This means diagnostics of level
were not shown.
Note: PHP Constants outside of PHP
Using PHP Constants outside of PHP, like in httpd.conf, will have no useful meaning so in such cases the int values are required. And since error levels will be added over time, the maximum value (for
E_ALL) will likely change. So in place of
E_ALLconsider using a larger value to cover all bit fields from now and well into the future, a numeric value like
2147483647(includes all errors, not just
This determines whether errors should be printed to the screen as part of the output or if they should be hidden from the user.
"stderr" sends the errors to
This is a feature to support your development and should never be used on production systems (e.g. systems connected to the internet).
Although display_errors may be set at runtime (with ini_set()), it won't have any effect if the script has fatal errors. This is because the desired runtime action does not get executed.
Even when display_errors is on, errors that occur during PHP's startup sequence are not displayed. It's strongly recommended to keep display_startup_errors off, except for debugging.
Tells whether script error messages should be logged to the server's error log or error_log. This option is thus server-specific.
You're strongly advised to use error logging in place of error displaying on production web sites.
Set the maximum length of log_errors in bytes. In error_log information about the source is added. The default is 1024 and 0 allows to not apply any maximum length at all. This length is applied to logged errors, displayed errors and also to $php_errormsg, but not to explicitly called functions such as error_log().When an int is used, the value is measured in bytes. Shorthand notation, as described in this FAQ, may also be used.
Do not log repeated messages. Repeated errors must occur in the same file on the same line unless ignore_repeated_source is set true.
Ignore source of message when ignoring repeated messages. When this setting is On you will not log errors with repeated messages from different files or sourcelines.
If this parameter is set to On (the default), this parameter will show a
report of memory leaks detected by the Zend memory manager. This report
will be sent to stderr on Posix platforms. On Windows, it will be sent
to the debugger using OutputDebugString() and can be viewed with tools
like » DbgView.
This parameter only has effect in a debug build and if
E_WARNING in the allowed
If enabled, the last error message will always be present in the variable $php_errormsg.
If enabled, error messages will include HTML tags. The format for HTML errors produces clickable messages that direct the user to a page describing the error or function in causing the error. These references are affected by docref_root and docref_ext.
If disabled, error message will be solely plain text.
If enabled, turns off normal error reporting and formats errors as XML-RPC error message.
Used as the value of the XML-RPC faultCode element.
The new error format contains a reference to a page describing the error or
function causing the error. In case of manual pages you can download the
manual in your language and set this ini directive to the URL of your local
copy. If your local copy of the manual can be reached by
you can simply use
docref_root=/manual/. Additional you have
to set docref_ext to match the fileextensions of your copy
docref_ext=.html. It is possible to use external
references. For example you can use
Most of the time you want the docref_root value to end with a slash
But see the second example above which does not have nor need it.
This is a feature to support your development since it makes it easy to lookup a function description. However it should never be used on production systems (e.g. systems connected to the internet).
The value of docref_ext must begin with a dot
String to output before an error message. Only used when the error message is displayed on screen. The main purpose is to be able to prepend additional HTML markup to the error message.
String to output after an error message. Only used when the error message is displayed on screen. The main purpose is to be able to append additional HTML markup to the error message.
Name of the file where script errors should be logged. The file should
be writable by the web server's user. If the
syslog is used, the errors
are sent to the system logger instead. On Unix, this means
syslog(3) and on Windows it means the event log. See also:
If this directive is not set, errors are sent to the SAPI error logger.
For example, it is an error log in Apache or
See also error_log().
Specifies what type of program is logging the message. Only effective if error_log is set to "syslog".
Specifies the filter type to filter the logged messages. Allowed
characters are passed unmodified; all others are written in their
hexadecimal representation prefixed with
all– the logged string will be split at newline characters, and all characters are passed unaltered
ascii– the logged string will be split at newline characters, and any non-printable 7-bit ASCII characters will be escaped
no-ctrl– the logged string will be split at newline characters, and any non-printable characters will be escaped
raw– all characters are passed to the system logger unaltered, without splitting at newlines (identical to PHP before 7.3)
This directive is not supported on Windows.
rawfilter type is available as of PHP 7.3.8 and PHP 7.4.0.
Specifies the ident string which is prepended to every message. Only effective if error_log is set to "syslog".