How to replace exec () through system command in php?

My Coding is so far:

How to replace exec() through system command in php?

if($str!="success")
{
   开发者_如何学JAVA $cmd = "rm -rf /portal/data/config/certificate/tmp/";
    $error_text="Command : ".$cmd;
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH);
    $output = exec($cmd,$array1,$error_code);
    $error_text="Error code : ".$error_code;
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH);
    seterror('0:|:  :|: Could not apply certificate.');
    $error_text="Could not apply certificate";
    AddLog("sslconfig.php",$error_text,ERR_INFO);
    header("Location: ssl.php");
    exit;
}

if($certName==$cert_auth)
{
    //copy the applied certificate to fireballbundle.crt
    //$output = copysslfb("/portal/data/config/certificate/".$newfile.".crt");
    $error_text="Selfsigned Certicate";
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH); 
    $output="success";
} 
else 
{
    $error_text="Not Selfsigned Certicate";
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH);
    $output="success";
}

if($output!="success")
{
    $cmd = "rm -rf /portal/data/config/certificate/tmp/";
    $error_text="Command : ".$cmd;
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH);
    $output = exec($cmd,$array1,$error_code);
    $error_text="Error code : ".$error_code;
    AddLog("sslconfig.php",$error_text,ERR_DEBUG_HIGH);
    $error_text="Could not add certificate to fireballbundle.crt : ".$output;
    AddLog("sslconfig.php",$error_text,ERR_ERROR);
    seterror('0:|: :|: Error in applying certificate.');
    header("Location: ssl.php");
    exit;
}

Now I want to replace exec command with system command ?

I am using three times exec() here as shown as above code now i want to replace with system () command in php

exec("hostname",$retval);
$output = exec($cmd,$array1,$error_code);
exec($cmd,$array1,$error_code);

To remove a single file, you should use unlink and to remove a directory you should use rmdir. In the comments on those pages, you will find many different ways to emulate rm -rf through these functions.

You should avoid using system or exec as much as is possible. Always look on php.net and google to see if you can find a way to do whatever you're trying to do with a built-in function or library. You have no need to use these facilities here.

What hostname returns you should probably use $_SERVER['SERVER_NAME'] for instead.