<?php
namespace ExecWithFallback;
/**
* Emulate exec() with system()
*
* @package ExecWithFallback
* @author Bjørn Rosell <it@rosell.dk>
*/
class ShellExec
{
/**
* Emulate exec() with shell_exec()
*
* @param string $command The command to execute
* @param string &$output (optional)
* @param int &$result_code (optional)
*
* @return string | false The last line of output or false in case of failure
*/
public static function exec($command, &$output = null, &$result_code = null)
{
$resultCodeSupplied = (func_num_args() >= 3);
if ($resultCodeSupplied) {
throw new \Exception('ShellExec::exec() does not support $result_code argument');
}
$result = shell_exec($command);
// result:
// - A string containing the output from the executed command,
// - false if the pipe cannot be established
// - or null if an error occurs or the command produces no output.
if ($result === false) {
return false;
}
if (is_null($result)) {
// hm, "null if an error occurs or the command produces no output."
// What were they thinking?
// And yes, it does return null, when no output, which is confirmed in the test "echo hi 1>/dev/null"
// What should we do? Throw or accept?
// Perhaps shell_exec throws in newer versions of PHP instead of returning null.
// We are counting on it until proved wrong.
return '';
}
$theOutput = preg_split('/\s*\r\n|\s*\n\r|\s*\n|\s*\r/', $result);
// remove the last element if it is blank
if ((count($theOutput) > 0) && ($theOutput[count($theOutput) -1] == '')) {
array_pop($theOutput);
}
if (count($theOutput) == 0) {
return '';
}
if (gettype($output) == 'array') {
foreach ($theOutput as $line) {
$output[] = $line;
}
} else {
$output = $theOutput;
}
return $theOutput[count($theOutput) -1];
}
}