php 调用系统命令

system 与 exec 

两者区别与联系：都会返回最后一行，命令执行成功的return返回值， 区别：system直接将输出内容echo出来，而exec将每一行输出内容保存到数组$output里。

echo "system:<br>";
$last_line = system('ls', $retval);
echo "<br>".$last_line;
echo "<br>".$retval;
             
$last_line = exec("ls",$output,$retval);
echo "<br><br>exec:";
echo "<br>".$last_line."<br>";
print_r($output);
echo "<br>".$retval;

结果：

system:
compress compressV2.rar phpinfo.php test.php ziparchive 
ziparchive
0

exec:
ziparchive
Array ( [0] => compress [1] => compressV2.rar [2] => phpinfo.php [3] => test.php [4] => ziparchive ) 
0