Sets a user function (error_handler) to handle errors in a
script. Returns the previously defined error handler (if
any), or FALSE on error.
This function can be used for defining your own way of
handling errors during runtime, for example in applications
in which you need to do cleanup of data/files when a critical
error happens, or when you need to trigger an error under
certain conditions (using
trigger_error())
The user function needs to accept 2 parameters: the
error code, and a string describing the error. From PHP
4.0.2, an additional 3 optional parameters are supplied: the
filename in which the error occurred, the line number in
which the error occurred, and the context in which the error
occurred (an array that points to the active symbol table at
the point the error occurred).
注: Instead of a function name, an array containing an object reference and a method name can also be supplied. (Since PHP 4.3.0)
注: The following error types cannot be handled with a user defined function: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR and E_COMPILE_WARNING.
The example below shows the handling of internal
exceptions by triggering errors and handling them with a user
defined function:
|
vector a Array ( [0] = 2 [1] = 3 [2] = foo [3] = 5.5 [4] = 43.3 [5] = 21.11 ) ---- vector b - a warning (b = log(PI) * a) b WARNING /b [1024] Value at position 2 is not a number, using 0 (zero) br Array ( [0] = 2.2894597716988 [1] = 3.4341896575482 [2] = 0 [3] = 6.2960143721717 [4] = 49.566804057279 [5] = 24.165247890281 ) ---- vector c - an error b ERROR /b [512] Incorrect input vector, array of values expected br NULL ---- vector d - fatal error b FATAL /b [256] log(x) for x = 0 is undefined, you used: scale = -2.5 br Fatal error in line 36 of file trigger_error.php, PHP 4.0.2 (Linux) br Aborting... br |
It is important to remember that the standard PHP error
handler is completely bypassed.
error_reporting() settings will have no effect and
your error handler will be called regardless - however you
are still able to read the current value of error_reporting
and act appropriately. Of particular note is that this value
will be 0 if the statement that caused the error was
prepended by the @ error-control
operator.
Also note that it is your responsibility to die() if
necessary. If the error-handler function returns, script
execution will continue with the next statement after the one
that caused an error.
注: If errors occur before the script is executed (e.g. on file uploads) the custom error handler cannot be called since it is not registered at that time.
See also error_reporting(),
restore_error_handler(),
trigger_error(),
user_error()