Check String and User Agent

I am trying to setup a PHP snippet that checks if 2 conditions are met and if they are, it echoes some text. The conditions are:

  1. That the query string equals a certain value.
  2. That the browser is Firefox.

It’s checking the query string properly but, it doesnt seem to be working for the browser (user agent). See below:

<?php

function get_user_browser()
{
    $u_agent = $_SERVER['HTTP_USER_AGENT'];
    $ub = '';
    if(preg_match('/Firefox/i',$u_agent))
    {
        $ub = "firefox";
    }
    else
    {
        $ub = "other";
    }

} 

if (isset($_GET['print']) && $_GET['print'] != "" && $ub = 'firefox') 
{
    $pg = $_GET['print'];
    if (!file_exists('1')) 
    {
        echo '<b>It worked!</b>';
    }
}
else 
{
    echo '';
}

?> 

Any help would be appreciated.

Here is Solutions:

We have many solutions to this problem, But we recommend you to use the first solution because it is tested & true solution that will 100% work for you.

Solution 1

This is what i do to check out that stuff:

if(strlen(strstr($_SERVER['HTTP_USER_AGENT'],"Firefox")) <= 0 ){ // if not firefox

  //do something

}

And added into your code:

function get_user_browser()
{
    $u_agent = $_SERVER['HTTP_USER_AGENT'];
    $ub = '';
    if(strlen(strstr($u_agent,"Firefox")) > 0 ){ 

      $ub = 'firefox';

    }
    else {
      $ub = 'other';
    }

    return $ub;
} 

if (isset($_GET['print']) && $_GET['print'] != "" 
                          && get_user_browser() == 'firefox') 
{
    $pg = $_GET['print'];
    if (!file_exists('1')) 
    {
        echo '<b>It worked!</b>';
    }
}
else 
{
    echo '';
}

Solution 2

Here is what i use;

function getBrowser() 
{ 
    $u_agent = $_SERVER['HTTP_USER_AGENT']; 
    $bname = 'Unknown';
    $platform = 'Unknown';
    $version= "";

//First get the platform?
if (preg_match('/linux/i', $u_agent)) {
    $platform = 'linux';
}
elseif (preg_match('/macintosh|mac os x/i', $u_agent)) {
    $platform = 'mac';
}
elseif (preg_match('/windows|win32/i', $u_agent)) {
    $platform = 'windows';
}

// Next get the name of the useragent yes seperately and for good reason
if(preg_match('/MSIE/i',$u_agent) && !preg_match('/Opera/i',$u_agent)) 
{ 
    $bname = 'Internet Explorer'; 
    $ub = "MSIE"; 
} 
elseif(preg_match('/Firefox/i',$u_agent)) 
{ 
    $bname = 'Mozilla Firefox'; 
    $ub = "Firefox"; 
} 
elseif(preg_match('/Chrome/i',$u_agent)) 
{ 
    $bname = 'Google Chrome'; 
    $ub = "Chrome"; 
} 
elseif(preg_match('/Safari/i',$u_agent)) 
{ 
    $bname = 'Apple Safari'; 
    $ub = "Safari"; 
} 
elseif(preg_match('/Opera/i',$u_agent)) 
{ 
    $bname = 'Opera'; 
    $ub = "Opera"; 
} 
elseif(preg_match('/Netscape/i',$u_agent)) 
{ 
    $bname = 'Netscape'; 
    $ub = "Netscape"; 
} 

// finally get the correct version number
$known = array('Version', $ub, 'other');
$pattern = '#(?<browser>' . join('|', $known) .
')[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';
if (!preg_match_all($pattern, $u_agent, $matches)) {
    // we have no matching number just continue
}

// see how many we have
$i = count($matches['browser']);
if ($i != 1) {
    //we will have two since we are not using 'other' argument yet
    //see if version is before or after the name
    if (strripos($u_agent,"Version") < strripos($u_agent,$ub)){
        $version= $matches['version'][0];
    }
    else {
        $version= $matches['version'][1];
    }
}
else {
    $version= $matches['version'][0];
}

// check if we have a number
if ($version==null || $version=="") {$version="?";}

return array(
    'userAgent' => $u_agent,
    'name'      => $bname,
    'version'   => $version,
    'platform'  => $platform,
    'pattern'    => $pattern
);

} 

you can also have a look at;

https://github.com/donatj/PhpUserAgent

Solution 3

I can’t see your code calling the function, and thus $ub doesn’t work in your condition.

<?php

$u_agent = $_SERVER['HTTP_USER_AGENT'];
$ub = 'other';
if(preg_match('/Firefox/i',$u_agent))
{
    $ub = "firefox";
}

if (isset($_GET['print']) && $_GET['print'] != "" && $ub == 'firefox') {
$pg = $_GET['print'];
if (!file_exists('1')) {
echo '<b>It worked!</b>';
}
} 
else {
echo '';
}
?> 

Note: Use and implement solution 1 because this method fully tested our system.
Thank you 🙂

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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