Hostgre


HomeReferencePHPPHP 5 Error Functions

PHP 5 Error Functions

PHP Error Introduction

The error functions are used to deal with error handling and logging. The error functions permit us to define own error handling rules, and modify the manner the errors is logged. The logging functions permit us to send messages on to different machines, emails, or system logs. The error reporting functions permit us to customize what level and type of error feedback is given.

Installation

The PHP error functions are part of the PHP core. No installation is needed to use these functions.

Runtime Configuration

The error functions is affected by the settings in php.ini. Errors and logging configuration options:
NameDefaultDescriptionChangeable
error_reportingNULLSet the error reporting level (either an integer or  named constants)PHP_INI_ALL
display_errors"1"Specify whether errors should be printed to the screen, or if they should be hidden from the user. Note: This feature should never be used on production systems (only to support your development)PHP_INI_ALL
display_startup_errors"0"Even when display_errors is on, errors that occur during PHP's startup sequence are not displayed Note: It is strongly recommended to keep display_startup_errors off, except for debuggingPHP_INI_ALL
log_errors"0"Define whether script error messages should be logged to the server's error log or error_log. Note: It is strongly advised to use error logging instead of error displaying on production web sitesPHP_INI_ALL
log_errors_max_len"1024"Set the maximum length of log_errors in bytes. The value "0" can be used to not apply any maximum length at all. This length is applied to logged errors, displayed errors, and also to $php_errormsg (available since PHP 4.3)PHP_INI_ALL
ignore_repeated_errors"0"Specify whether to log repeated error messages. When set to "1" it will not log errors with repeated errors from the same file on the same line (available since PHP 4.3)PHP_INI_ALL
ignore_repeated_source"0"Specify whether to log repeated error messages. When set to "1" it will not log errors with repeated errors from different files or source lines (available since PHP 4.3)PHP_INI_ALL
report_memleaks"1"If set to "1" (the default), this parameter will show a report of memory leaks detected by the Zend memory manager (available since PHP 4.3)PHP_INI_ALL
track_errors"0"If set to "1", the last error message will always be present in the variable $php_errormsgPHP_INI_ALL
html_errors"1"Turn off HTML tags in error messagesPHP_INI_ALL PHP_INI_SYSTEM in PHP <= 4.2.3.
xmlrpc_errors"0"Turn off normal error reporting and formats errors as XML-RPC error message (available since PHP 4.1)PHP_INI_SYSTEM
xmlrpc_error_number"0"Used as the value of the XML-RPC faultCode element (available since PHP 4.1)PHP_INI_ALL
docref_root""(available since PHP 4.3)PHP_INI_ALL
docref_ext""(available since PHP 4.3.2)PHP_INI_ALL
error_prepend_stringNULLSpecify a string to output before an error messagePHP_INI_ALL
error_append_stringNULLSpecify a string to output after an error messagePHP_INI_ALL
error_logNULLSpecify the name of the file where script errors should be logged. The file should be writable by the web server's user. If the special value syslog is used, the errors are sent to the system logger insteadPHP_INI_ALL

PHP Error and Logging Functions

FunctionDescription
debug_backtrace()Generate a backtrace
debug_print_backtrace()Print a backtrace
error_get_last()ReTurn the last error that occurred
error_log()Send an error message to a log, to a file, or to a mail account
error_reporting()Specify which errors are reported
restore_error_handler()Restore the previous error handler
restore_exception_handler()Restore the previous exception handler
set_error_handler()Set a user-defined error handler function
set_exception_handler()Set a user-defined exception handler function
trigger_error()Create a user-level error message
user_error()Alias of trigger_error()

PHP 5 Predefined Error and Logging Constants

ValueConstantDescription
1E_ERRORFatal run-time errors. Errors that cannot be recovered from. Execution of the script is halted
2E_WARNINGRun-time warnings (non-fatal errors). Execution of the script is not halted
4E_PARSECompile-time parse errors. Parse errors should only be generated by the parser
8E_NOTICERun-time notices. The script found something that might be an error, but could also happen when running a script normally
16E_CORE_ERRORFatal errors at PHP startup. This is like E_ERROR, except it is generated by the core of PHP
32E_CORE_WARNINGNon-fatal errors at PHP startup. This is like E_WARNING, except it is generated by the core of PHP
64E_COMPILE_ERRORFatal compile-time errors. This is like E_ERROR, except it is generated by the Zend Scripting Engine
128E_COMPILE_WARNINGNon-fatal compile-time errors. This is like E_WARNING, except it is generated by the Zend Scripting Engine
256E_USER_ERRORFatal user-generated error. This is like E_ERROR, except it is generated in PHP code by using the PHP function trigger_error()
512E_USER_WARNINGNon-fatal user-generated warning. This is like E_WARNING, except it is generated in PHP code by using the PHP function trigger_error()
1024E_USER_NOTICEUser-generated notice. This is like E_NOTICE, except it is generated in PHP code by using the PHP function trigger_error()
2048E_STRICTEnable to have PHP suggest changes to your code which will ensure the best interoperability and forward compatibility of your code (Since PHP 5 but not included in E_ALL until PHP 5.4)
4096E_RECOVERABLE_ERRORCatchable fatal error. Indicates that a probably dangerous error occurred, but did not leave the Engine in an unstable state. If the error is not caught by a user defined handle, the application aborts as it was an E_ERROR (Since PHP 5.2)
8192E_DEPRECATEDRun-time notices. Enable this to receive warnings about code that will not work in future versions (Since PHP 5.3)
16384E_USER_DEPRECATEDUser-generated warning message. This is like E_DEPRECATED, except it is generated in PHP code by using the PHP function trigger_error() (Since PHP 5.3)
32767E_ALLEnable all PHP errors and warnings (except E_STRICT in versions < 5.4)