PHP exec - check if enabled or disabled
Is there a way to check in a php 开发者_如何学编程script if exec()
is enabled or disabled on a server?
This will check if the function actually works (permissions, rights, etc):
if(@exec('echo EXEC') == 'EXEC'){
echo 'exec works';
}
if(function_exists('exec')) {
echo "exec is enabled";
}
ini_get('disable_functions')
What you actually want to do is use ini_get('disable_functions')
to find out if it is available to you:
<?php
function exec_enabled() {
$disabled = explode(',', ini_get('disable_functions'));
return !in_array('exec', $disabled);
}
?>
Answered on stackoverflow here: Check if "exec" is disabled, Which actually seems to come from the PHP Man page: http://php.net/manual/en/function.exec.php#97187
Path
If the above returns true (you can use exec()), but PHP can still not trigger the script there is a good chance that you have a path issue for that script, test this by doing:
print exec('which bash');
and then try
print exec('which ogr2ogr');
This will check that exec is available and enabled BEFORE trying to run it. If you run exec() and the function does not exist or is disabled a warning will be generated. Depending on the server settings that may render to the browser and will almost-always write a line to a log file = performance hit.
// Exec function exists.
// Exec is not disabled.
// Safe Mode is not on.
$exec_enabled =
function_exists('exec') &&
!in_array('exec', array_map('trim', explode(', ', ini_get('disable_functions')))) &&
strtolower(ini_get('safe_mode')) != 1
;
if($exec_enabled) { exec('blah'); }
It's a bit tricky to find exec
function available until unless checking all possibilities
1.function_exist('exec')
2.Scanning through ini_get('disabled_functions)
3.Checking safe_mode
enabled
function is_shell_exec_available() {
if (in_array(strtolower(ini_get('safe_mode')), array('on', '1'), true) || (!function_exists('exec'))) {
return false;
}
$disabled_functions = explode(',', ini_get('disable_functions'));
$exec_enabled = !in_array('exec', $disabled_functions);
return ($exec_enabled) ? true : false;
}
This function never throws warnings unless ini_get
function not disabled.
I am assuming that you are running this on a linux server.
You could test the exec function by running the following php script:
exec("whoami", $ret);
echo $ret[0];
This will return the command whoami.
If it errors out, it is because the exec function could not run.
Example:
if(strpos(ini_get('disable_functions'),'ini_set')===false)
@ini_set('display_errors',0);
This is some ugly code I made to detect if a function is enabled or not.
function is_enabled($f)
{
if($f=='ini_get')return@ini_get('a')===false;
return(($l=@ini_get('disable_functions'))===null||!is_callable($f)||!function_exists($f)||!in_array($f,array_map('trim',explode(',',$l)));
}
//Usage example:
print_r(is_enabled('str_split'));//true or null if ini_get() is disabled
(Based on other responses) To check if exec exists and services are running:
function isRunning($serviceName)
{
return exec('pgrep '.$serviceName);
}
if (@exec('echo EXEC') == 'EXEC') {
$services = [
'mysql',
'nginx',
'redis',
'supervisord',
];
foreach ($services as $service) {
if (isRunning($service)) {
echo $service.' service is running.<br>';
} else {
echo $service.' service is down.<br>';
}
}
}
// mysql service is running.
// nginx service is running.
// redis service is running.
// supervisord service is down.
I would use this:
if (in_array('exec', preg_split('/\s*,\s*/', ini_get('disable_functions')) {
echo "exec is disabled";
}
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