php exec/shelll_exec

[map200uk]

hi,

 

bit confused at present,

 

if i do

 

$output = shell_exec('ln');

echo "<pre>$output</pre>";

 

i get no result

 

but yet for df-h / uptime/whoami/ ls -art etc a result is shown

 

ive checked the user 'nobody' and it has permission to run the ln command? so surely i should get some kind of response

 

 

[DaveEverFade]

I don't know much about shell_exec but you might wanna try my favourite bit of code (before the command) to help diaganose the problem 

 

error_reporting(E_ALL);
ini_set('display_errors', '1');

[map200uk]

tried it-got nothing

 

bit confused as to why most commands work but for ln i get nothing, not even the

root@clark xmltest]# ln

ln: missing file argument

Try `ln --help' for more information.

 

[map200uk]

anyone have any ideas?:|

[map200uk]

bump any ideas? didnt wanna repost-but im still no wiser as to what could be causing this

[neel_basu]

Cause you havn't given any arguments with that command but that needs arguments

See thsi page http://linux.about.com/od/commands/l/blcmdl1_ln.htm for help on this command

[utexas_pjm]

As the previous poster suggested ln cannot be run without arguments.  If you type ln into the console you'll get

 

 

ln: missing file argument

Try `ln --help' for more information.

 

 

However this is sent to std error not std out.  I believe exec only returns output piped through std out.

 

Best,

 

Patrick

[map200uk]

ahhh ok i get it, i thought id get the error message too

 

thanks mate

[map200uk]

see thing is it works- you were correct thank you!

 

is there no way to check the command has been executed like with say whoami i could do

 

if(exec('whoami')

{ echo "bla"

} else {

echo "blaa";

}

 

thankls guys

[effigy]

I recommend always:

 

1. Redirecting STDERR to STDOUT (2>&1).

2. Checking the return value of the command.

[map200uk]

surely tho if the command executes perfectly there is no return? nothing passed to stdout?

[effigy]

A command always has a return value. Success is typically 0, with errors and warnings being non-zero.

[map200uk]

ahh right ok a boolean value yea, no output tho i meant

 

could someone help with a problem with exec-when i use exec to create sym links the script NEVER finished

 

function findMusic($dir) {

    $musicList = array();

    $dirHandle = opendir($dir);

    $dir2 = "/opt/lampp/htdocs//mp3";

 

  //  echo "<br> DIRECTOR IS \n $dir";

    while (($file = readdir($dirHandle)) !== FALSE) {

          if ($file == "." || $file == "..") continue;

          if (is_dir($dir . "/" . $file)) $musicList = array_merge($musicList, findMusic($dir . "/" . $file));

          else {

              $extension = end(explode(chr(46), $file));

                          // print $extension;

              if (strtolower($extension) == "mp3") { $musicList[] = $dir . "/" . $file; }

 

        echo "<br>mp3 found in \n $dir";

        echo "<br>commnd is \n $command";

        echo "attempting to create some sym links";

//      shell_exec("ln -s $dir $dir2");

 

}

 

 

}

 

        closedir($dirHandle);

    return $musicList;

}

[trq]

You would be best off using php's symlink function.

[map200uk]

i did look at that, so it would work same way?

 

if dir found pass the dir to symlink along with htdocs/mp3 and i now have a symlink in htdocs/mp3?

 

thanks bud

[trq]

Read the manual entry. You need to provide a name for the symlink, not just the directory you want it to appear in.

 

symlink("filebeinglinkedto","nameoflink");