PHP supports one error control operator: the at sign (@). When
prepended to an expression in PHP, any error messages that might
be generated by that expression will be ignored.
If the track_errors
feature is enabled, any error message generated by the expression
will be saved in the global variable $php_errormsg. This variable
will be overwritten on each error, so check early if you want to
use it.
<?php
/* Intentional file error */
$my_file = @file ('non_existent_file') or
die ("Failed opening file: error was '$php_errormsg'");
// this works for any expression, not just functions:
$value = @$cache[$key];
// will not issue a notice if the index $key doesn't exist.
?>
Note:
The @-operator works only on expressions. A simple rule of thumb
is: if you can take the value of something, you can prepend the @
operator to it. For instance, you can prepend it to variables,
function and include() calls, constants, and
so forth. You cannot prepend it to function or class definitions,
or conditional structures such as if and
foreach, and so forth.
Currently the "@" error-control operator prefix will even disable
error reporting for critical errors that will terminate script
execution. Among other things, this means that if you use "@" to
suppress errors from a certain function and either it isn't
available or has been mistyped, the script will die right there
with no indication as to why.
