PHP: Why isn't exec() returning output?
I'm writing a PHP script to be used to check for network connections with Linux shell command ping calling it with PHP's exec() :
<?php
// Bad IP domain for testing.
$domain_bad = "lksjdflksjdf.com";
$ip_address = $domain_bad;
exec("ping -c 1 $domain_bad", $output, $return_var);
var_dump($return_var);
echo "return_var is: $return_var" . "n";
var_dump($output);
exit;
?>
I'm not getting the output for the error message from ping in $output which is what I'm expecting:
$ php try.php
ping: unknown host lksjdflksjdf.com
int(2)
return_var is: 2
array(0) {
}
If the domain is a good domain, such as yahoo.com, then $output has the output from ping in an array. But if it's an error such as 'ping: unknown host lksjdflksjdf.com' it doesn't get returned to the $output array.
Why is this happening and is there a better method to do this?
You should redirect stderr to stdout.
To do that, change your exec() call like this:
exec("ping -c 1 $domain_bad 2>&1", $output, $return_var);
More info about 2>&1 meaning here.
如果有人来到这里并且无法解决您的问题，请尝试在disabled_functions行检查php.ini文件。
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