Checking for http:// in urls ?

[jeddi]

Hi

I have used the this code to ensure that I get a vaild
url ( or I use "none" value )

PHP Code:

if(!filter_var($Db_return, FILTER_VALIDATE_URL)) {
  $Db_return = "none";
  } // end if 


Now I just want to make sure that there is an http://
in place so that the re-direct will work.

PHP Code:

if( $return == "none"){
  $return_path="thankyou.php";
  }  // endif
else {    
  if( substr($return, 0, 7) != "http://" || substr($return, 0, 8) != "https://") {
    $return = "http://".$return;
    }  // endif
  else {    
    $return_path = $return;
    }  // end else
}  // end else

header("Location: $return_path"); 


Is this a good way to deal with checking for the re-direct ?
Or is there another built-in function I should use ?


Thanks


.

[Fou-Lu]

You can use parse_url. If http[s] is omitted there will be no value for the returned array's 'scheme' index. So then you can just check

PHP Code:

$sURL = $return;
if (false !== ($aURL = parse_url($return))
{
    if (!isset($aURL['scheme']))
    {
        $sURL = 'http://' . $sURL;
    }
} 


If you have pecl installed, there is also an http_build_url, so you can just append the 'scheme' to the $aURL and then build it.

[kbluhm]

Some more solutions:

PHP Code:

// recommended
if ( 0 !== stripos( $return, 'http://' ) )
{
    $return = 'http://' . $return; 
}

// will also work
if ( 'http://' != substr( $return, 0, 7 ) )
{
    $return = 'http://' . $return; 
} 


The use of stripos() ensures case-insensitivity... should the URL begin with HTTP://, etc.

[jeddi]

That certainly looks neater than my effort


Just thinking ...

Because of the "not equal" should ...

PHP Code:

if( substr($return, 0, 7) != "http://" || substr($return, 0, 8) != "https://") { 


really be ...

PHP Code:

 if( substr($return, 0, 7) != "http://"  && substr($return, 0, 8) != "https://") { 


I get confused with negatives


.

[kbluhm]

You could use a regular expression to match both http:// and https:// without having to use multiple conditions:

PHP Code:

if ( ! preg_match( '~^https?\://~i', $return ) )
{
    $return = 'http://' . $return;
} 


~ are delimiters
^ binds the match to the beginning of the string
? makes he previous character optional (matchs both http and https)
\ escapes the colon because it is a special character in PCRE
i makes the match case-insensitive

[jmj001]

Originally Posted by jeddi

That certainly looks neater than my effort


Just thinking ...

Because of the "not equal" should ...

PHP Code:

if( substr($return, 0, 7) != "http://" || substr($return, 0, 8) != "https://") { 


really be ...

PHP Code:

 if( substr($return, 0, 7) != "http://"  && substr($return, 0, 8) != "https://") { 


I get confused with negatives


.

it should && because || will always be true