$php_errormsg — 前一个错误信息
This feature has been DEPRECATED as of PHP 7.2.0. Relying on this feature is highly discouraged.
$php_errormsg 变量包含由 PHP 生成的最新错误信息。这个变量只在错误发生的作用域内可用，并且要求 track_errors 配置项是开启的（默认是关闭的）。
如果用户定义了错误处理句柄（set_error_handler()）并且返回 FALSE 的时候，$php_errormsg 就会被设置。
Example #1 $php_errormsg 范例
<?php
@strpos();
echo $php_errormsg;
?>
以上例程的输出类似于：
Wrong parameter count for strpos()
$php_errormsg does not contain the error message generated inside a function. See the example below:
<?php
@strpos();
function checkErrormsg()
{
global $php_errormsg;
echo "First Error is: $php_errormsg <br />";
@ini_set();
echo "Error is: $php_errormsg";
}
checkErrormsg();
?>
This will output:
First Error is: strpos() expects at least 2 parameters, 0 given
Error is: strpos() expects at least 2 parameters, 0 given
While $php_errormsg is a global, it is not a superglobal.
You'll have to qualify it with a global keyword inside a function.
<?php
function checkErrormsg()
{
global $php_errormsg;
@strpos();
return $php_errormsg;
}
?>
The track_errors parameter is PHP_INI_ALL, so you can use code like this:
<?php
ini_set('track_errors', 1);
$result = @do_risky_thing();
if (! $result) {
echo '<p>Error' . htmlspecialchars($php_errormsg) . '</p>';
}
ini_set('track_errors', 0);
?>
Note: This variable doesn't seem to get populated if you're running Xdebug.