PHP Checking if URL/File Exists... Return True/False

[Voodoo]

<?php if(file_exists("http://www.site.com/images/$id/misc6.jpg")){ DO THIS }?>

For some reason this doesn't seem to work. When I remove this check, the image shows up under { DO THIS }, however, the check doesn't seem to be returning a TRUE on this statement. What's the best way to return TRUE/FALSE for a remote image if it exists?

EDIT: Note... $id is assigned above this statement.

[Voodoo]

Bumpity Bump

[Varius]

file_exists doesn't support checks on remote files.

why not just try with fopen ?

[Dirty D]

also make sure

allow_url_fopen is enabled

(Dirty D has chicks in the pool on Labor Day, why am I commenting on someone else's code?)

[mikeyddddd]

(Dirty D has chicks in the pool on Labor Day, why am I commenting on someone else's code?)

Shrinkage

[calmlikeabomb]

The most secure way to accomplish what you need is using cURL.

Many will argue that enabling URL wrappers is a potential security risk within PHP. Just google and you'll find many articles. This is why that option is turned off by default in the configuration file.

[nation-x]

if the file is an image every time... you can use getimagesize >> http://us2.php.net/getimagesize

[b]Example #3 getimagesize (URL)[/b]
<?php
$size = getimagesize("http://www.example.com/gifs/logo.gif");

// if the file name has space in it, encode it properly
$size = getimagesize("http://www.example.com/gifs/lo%20go.gif");

?>

[nation-x]

The most secure way to accomplish what you need is using cURL.

Many will argue that enabling URL wrappers is a potential security risk within PHP. Just google and you'll find many articles. This is why that option is turned off by default in the configuration file.

allow_url_fopen isn't really a big risk... allow_url_include is.

[calmlikeabomb]

allow_url_include doesn't work unless allow_url_fopen is enabled, buddy.

[nation-x]

allow_url_include doesn't work unless allow_url_fopen is enabled, buddy.

They have separate flags... so it is possible to enable allow_url_fopen and turn off allow_url_include.

[Davy]

[GrouchyAdmin]

This is incredibly basic shit. The following is a top-down-no-classes-used example, using cURL, as suggested above. Note the lack of RETURNTRANSFER as we're only checking the status code.

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,"http://www.site.com/blah/");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 0);
curl_setopt($ch,CURLOPT_VERBOSE, FALSE);
curl_setopt($ch, CURLOPT_TIMEOUT, 5);
$pageData=curl_exec($ch);
$statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

switch ($statusCode) {
  case 404:
    filemissing()...
    break;
  case 401:
    authreq();
    break;
  default:
   whatev();
}

if the file is an image every time... you can use getimagesize >> http://us2.php.net/getimagesize

Do not use getimagesize() as a boolean for validation - that is VERY unsafe.

[nation-x]

Do not use getimagesize() as a boolean for validation - that is VERY unsafe.

Please provide an example to prove your assertion... how exactly is this unsafe?

This is how I would use it.

$file_url = "http://www.site.com/images/{$id}/misc6.jpg";
$file_exists = is_array($file_url);

[GrouchyAdmin]

Please provide an example to prove your assertion... how exactly is this unsafe?[/code]

Generally, lazily coded image hosting scripts. The easiest way to abuse this I've actually seen in the wild. It starts with a valid GIF header, and has a PHP script as the payload. WIthout giving away too many details, file naming conventions and autonegotiation can cause you bigtime issues.

[nation-x]

should have been:

$file_url = "http://www.site.com/images/{$id}/misc6.jpg";
$file_exists = is_array(getimagesize($file_url));

[MichaelP]

$yourfile = "full/path/to/your/file.php-jpg-gif-whatever" ;
IF (file_exists($yourfile)) {
print "Your File Does Existst" ; // TRUE
} ELSE {
print "Your file Doesn't exists" ; // FALSE
}

[Tom_PM]

I ran into this issue long ago, but I think I solved it by realising that both domains I was working with were on the same server, doh!

Good luck.

[Killswitch - BANNED FOR LIFE]

$yourfile = "full/path/to/your/file.php-jpg-gif-whatever" ;
IF (file_exists($yourfile)) {
print "Your File Does Existst" ; // TRUE
} ELSE {
print "Your file Doesn't exists" ; // FALSE
}

Not gonna work captain.

[ProG]

Not gonna work captain.

I don't even think he read the thread.

[GrouchyAdmin]

Jeeesus peoples. This is a hack of a slightly-better-than-my-above for just checking for the files' existence, based upon code at PHP.net; I figured this thread should die a horrible death, so here ya go.

function http_file_exists($url=FALSE) {
  // Bad URL, bail.
  if (!(@parse_url($url))) return FALSE;
  // No cURL, bail.
  if (!(function_exists('curl_init'))) return FALSE;
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL,$url);
  curl_setopt($ch, CURLOPT_NOBODY, 1);
  curl_setopt($ch, CURLOPT_FAILONERROR, 1);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  return (curl_exec($ch) !== FALSE) ? TRUE : FALSE;
}

Here's even a (shitty) working example:

$urltest = array ("http://www.google.com/logo.gif", "http://www.google.com/intl/en_ALL/images/logo.gif");

foreach ($urltest as $url) {
  echo http_file_exists($url) ? "$url exists.\n" : "$url is a 404.\n";
}
exit;

http://www.google.com/logo.gif is a 404.
http://www.google.com/intl/en_ALL/images/logo.gif exists.

Can this go away now pls?

[nation-x]

Jeeesus peoples. Can this go away now pls?

buttsecks???!!! :D

[GrouchyAdmin]

buttsecks???!!! :D

I gave at the office.

[Killswitch - BANNED FOR LIFE]

Jeeesus peoples. This is a hack of a slightly-better-than-my-above for just checking for the files' existence, based upon code at PHP.net; I figured this thread should die a horrible death, so here ya go.

function http_file_exists($url=FALSE) {
  // Bad URL, bail.
  if (!(@parse_url($url))) return FALSE;
  // No cURL, bail.
  if (!(function_exists('curl_init'))) return FALSE;
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL,$url);
  curl_setopt($ch, CURLOPT_NOBODY, 1);
  curl_setopt($ch, CURLOPT_FAILONERROR, 1);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  return (curl_exec($ch) !== FALSE) ? TRUE : FALSE;
}

Here's even a (shitty) working example:

$urltest = array ("http://www.google.com/logo.gif", "http://www.google.com/intl/en_ALL/images/logo.gif");

foreach ($urltest as $url) {
  echo http_file_exists($url) ? "$url exists.\n" : "$url is a 404.\n";
}
exit;

http://www.google.com/logo.gif is a 404.
http://www.google.com/intl/en_ALL/images/logo.gif exists.

Can this go away now pls?

No, I refuse to let it! BUMMMPPP!!

[GrouchyAdmin]

No, I refuse to let it! BUMMMPPP!!

I cutchoo mang. I cutchoo so bad you wish I no cutchoo.


...and I'm gonna keep using a banned imagehost until this damn thing goes away. S'there!

[Killswitch - BANNED FOR LIFE]

I cutchoo mang. I cutchoo so bad you wish I no cutchoo.


...and I'm gonna keep using a banned imagehost until this damn thing goes away. S'there!

I cut you back... I cut you deep, I cut you so deep, yo momma be like "WTF IS THAT!?!?".

Imageshack works on gfy.com, fail.

[GrouchyAdmin]

Imageshack works on gfy.com, fail.

LOS GROUCHY KICK YOUR ASS
LOS GROUCHY KICK YOUR FACE
LOS GROUCHY http_file_exists() IN TO OUTER SPACE

Dammit. It used to be banned as far back as.. two weeks ago.

[munki]

[Killswitch - BANNED FOR LIFE]

LOS GROUCHY KICK YOUR ASS
LOS GROUCHY KICK YOUR FACE
LOS GROUCHY http_file_exists() IN TO OUTER SPACE

Dammit. It used to be banned as far back as.. two weeks ago.

LOS GROUCHY KICK ROCKS
LOS GROUCHY NO HURT
LOS GROUCHY http_file_exists() RETURN ERROR FOR SUCKAGE

Hmm, weird, that little smiley you posted from imageshack showed for me on gfy.com

[GrouchyAdmin]

LOS GROUCHY KICK ROCKS
LOS GROUCHY NO HURT
LOS GROUCHY http_file_exists() RETURN ERROR FOR SUCKAGE

Hmm, weird, that little smiley you posted from imageshack showed for me on gfy.com

Yeah, well, you're Retox_Josh.

Feel that burn, motherbitch. Feel it!? Mmmyeah. That's the stuff.

[quantum-x]

return (!file_get_contents('URL')?false:true);
Do I win ?

[Killswitch - BANNED FOR LIFE]

Yeah, well, you're Retox_Josh.

Feel that burn, motherbitch. Feel it!? Mmmyeah. That's the stuff.

Touché

You win this time my little pretty, but I will get you and your dog too!

[GrouchyAdmin]

return (!file_get_contents('URL')?false:true);
Do I win ?

No. Michael P wins for 'not reading the fucking thread at all', but nice try.

Touché

You win this time my little pretty, but I will get you and your dog too!

Surrender Grouchy, my ass.

[quantum-x]

No. Michael P wins for 'not reading the fucking thread at all', but nice try.



Surrender Grouchy, my ass.

Damnit .

[munki]

[GrouchyAdmin]

Damnit .

You do get a few points for ternary abuse, though.

[quantum-x]

You do get a few points for ternary abuse, though.

If you cram it aaaalllll onto one line, if the script ever breaks, at least you know the line to debug