Using PHP Execution Functions: exec, system, passthru, popen, proc_open, and shell_exec

1. exec function

<?php
  $test = "ls /tmp/test";   // ls is the Linux command to list directory contents
  exec($test,$array);       // execute command
  print_r($array);
?>

2. system function

<?php
  $test = "ls /tmp/test";
  $last = system($test);
  print "last: $last\n";
?>

3. passthru function

<?php
  $test = "ls /tmp/test";
  passthru($test);
?>

4. popen function

<?php
  $test = "ls /tmp/test";
  $fp = popen($test, "r");  // open a process pipe
  while (!feof($fp)) {      // read from the pipe
    $out = fgets($fp, 4096);
    echo $out;         // output the data
  }
  pclose($fp);
?>

5. proc_open function

<?php
  $test = "ls /tmp/test";
  $descriptors = array(
    array("pipe", "r"),   // stdin
    array("pipe", "w"),   // stdout
    array("pipe", "w")    // stderr
  );
  $fp = proc_open($test, $descriptors, $pipes);   // open a process with pipes
  echo stream_get_contents($pipes[1]);    // read stdout (index 1)
  proc_close($fp);
?>

6. proc_open function (duplicate example)

<?php
  $test = "ls /tmp/test";
  $descriptors = array(
    array("pipe", "r"),   // stdin
    array("pipe", "w"),   // stdout
    array("pipe", "w")    // stderr
  );
  $fp = proc_open($test, $descriptors, $pipes);   // open a process with pipes
  echo stream_get_contents($pipes[1]);    // read stdout (index 1)
  proc_close($fp);
?>

7. shell_exec function

<?php
  $test = "ls /tmp/test";
  $out = shell_exec($test);
  echo $out;
?>