Linux Executing bash scripts from a webpage

I've seen on a couple of utility distros (ipcop, geexbox) on their webgui they have a button to shutdown the system or perform specific operations ie in geex play a file in mplayer. Basicaly i think they are executing bash scripts but i might be wrong. Could some one help me understand how this is done it could be handy for my juke box and if it just a bash script how would one call it from a web page.

 

You'll likely find they're using customised versions of Apache's httpd, or perhaps Apache Tomcat. However, you can do something similar if you have apache and php installed on your machine. You can write a php script to execute commands on the server (which would be your PC) and optionally output the result to the page. The command is either "shell_exec()" or enclosing the command in backticks. Check the PHP page for more info: http://uk2.php.net/manual/en/function.shell-exec.php

As a for-instance:

<?php
// execute 'ls -l', save the results in $comout, echo it out to the page
$comout = shell_exec('ls -l');
echo "<pre>$comout </pre>";
?>

This will execute a directory list, and output that list to your web page. The link I gave also has links to similar commands that might be useful, depending on what you wanted to do.

 

yup.
shellexec() is the right way to do shell commands on a 'nix box through PHP.
HOWEVER, there's a HUGE security risk involved with the whole thing (potentially). But i assume you want to use this for your table-based PC mod?

 

Its for a different project but yeah its on my internal network no where near the internet.

 

While it's not using bash, it's sometimes more powerful to use PHP itself. Here's the recursive function I use on my intranet.

PHP:

function scanFilesystem($dir) {
  $itemArray = scandir($dir);

  for($i=2; $i<count($itemArray); $i++) {
    $item = $itemArray[$i];
    $newDir = $dir . "/" . $item;

    if(is_dir($newDir)) {
      $tempArray[$item] = scanFilesystem($newDir);
      asort($tempArray);
    }
    else {
      $tempArray[] = $item;
    }

  }

  return $tempArray;
}


Assuming the following directory structure:

Code:

root/html
root/html/index.php
root/html/about.php
root/html/archives.php
root/html/images/logo.png
root/html/images/photo.png
root/html/images/icons/arrow.png
root/html/images/icons/pencil.png
root/html/images/icons/paper.png
root/html/style/style.css

Then calling scanFilesystem() as follows:

PHP:

$dir = "root/html";
$dirStructure = scanFilesystem($dir);
print_r($dirStructure);


Will give the output:

PHP:

Array
(
    [0] => about.php
    [1] => archives.php
    [2] => index.php
    [images] => Array
        (
            [0] => logo.png
            [1] => photo.png
            [icons] => Array
                (
                    [0] => arrow.png
                    [1] => pencil.png
                    [2] => paper.png
                )
        )

    [style] => Array
        (
            [0] => style.css
        )
)

Now just print the array using a foreach/for loop et volia.

Good for displaying mp3 etc..

 

Perl/CGI is able to execute command-line/bash commands to a certain degree. For example:

Code:

open(TAR, "/bin/tar -zxvf some-file.tar.gz |") || die "Could not extract files ($!)\n";

[b]or call system commands like so:[/b]

system("/bin/rm -rf some/path/somefolder/");

 

Why are you recursively removing a single file? -r is for deleting directories.

 

My bad, didn't check what I wrote. Shouldn't be .tar.gz -- should just be a folder.