Transform relative path into absolute URL using PHP

Question

How to, using php, transform relative path to absolute URL?

Answer 1

function rel2abs($rel, $base) {     /* return if already absolute URL */     if (parse_url($rel, PHP_URL_SCHEME) != '') return $rel;      /* queries and anchors */     if ($rel[0]=='#' || $rel[0]=='?') return $base.$rel;      /* parse base URL and convert to local variables:        $scheme, $host, $path */     extract(parse_url($base));      /* remove non-directory element from path */     $path = preg_replace('#/[^/]*$#', '', $path);      /* destroy path if relative url points to root */     if ($rel[0] == '/') $path = '';      /* dirty absolute URL */     $abs = "$host$path/$rel";      /* replace '//' or '/./' or '/foo/../' with '/' */     $re = array('#(/\.?/)#', '#/(?!\.\.)[^/]+/\.\./#');     for($n=1; $n>0; $abs=preg_replace($re, '/', $abs, -1, $n)) {}      /* absolute URL is ready! */     return $scheme.'://'.$abs; } 

Answer 2

I love the code that jordanstephens provided from the link! I voted it up. l0oky inspired me to make sure that the function is port, username, and password URL compatible. I needed it for my project.

function rel2abs( $rel, $base ) {     /* return if already absolute URL */     if( parse_url($rel, PHP_URL_SCHEME) != '' )         return( $rel );      /* queries and anchors */     if( $rel[0]=='#' || $rel[0]=='?' )         return( $base.$rel );      /* parse base URL and convert to local variables:        $scheme, $host, $path */     extract( parse_url($base) );      /* remove non-directory element from path */     $path = preg_replace( '#/[^/]*$#', '', $path );      /* destroy path if relative url points to root */     if( $rel[0] == '/' )         $path = '';      /* dirty absolute URL */     $abs = '';      /* do we have a user in our URL? */     if( isset($user) )     {         $abs.= $user;          /* password too? */         if( isset($pass) )             $abs.= ':'.$pass;          $abs.= '@';     }      $abs.= $host;      /* did somebody sneak in a port? */     if( isset($port) )         $abs.= ':'.$port;      $abs.=$path.'/'.$rel;      /* replace '//' or '/./' or '/foo/../' with '/' */     $re = array('#(/\.?/)#', '#/(?!\.\.)[^/]+/\.\./#');     for( $n=1; $n>0; $abs=preg_replace( $re, '/', $abs, -1, $n ) ) {}      /* absolute URL is ready! */     return( $scheme.'://'.$abs ); }