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Php if file exists include path

Содержание
  1. file_exists
  2. Return Values
  3. Errors/Exceptions
  4. Examples
  5. Notes
  6. See Also
  7. User Contributed Notes 31 notes
  8. stream_resolve_include_path
  9. Parameters
  10. Return Values
  11. Examples
  12. User Contributed Notes 5 notes

file_exists

On windows, use //computername/share/filename or \\computername\share\filename to check files on network shares.

Return Values

Returns true if the file or directory specified by filename exists; false otherwise.

Note:

This function will return false for symlinks pointing to non-existing files.

Note:

The check is done using the real UID/GID instead of the effective one.

Note: Because PHP’s integer type is signed and many platforms use 32bit integers, some filesystem functions may return unexpected results for files which are larger than 2GB.

Errors/Exceptions

Upon failure, an E_WARNING is emitted.

Examples

Example #1 Testing whether a file exists

if ( file_exists ( $filename )) echo «The file $filename exists» ;
> else echo «The file $filename does not exist» ;
>
?>

Notes

Note: The results of this function are cached. See clearstatcache() for more details.

As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to Supported Protocols and Wrappers to determine which wrappers support stat() family of functionality.

See Also

  • is_readable() — Tells whether a file exists and is readable
  • is_writable() — Tells whether the filename is writable
  • is_file() — Tells whether the filename is a regular file
  • file() — Reads entire file into an array
  • SplFileInfo

User Contributed Notes 31 notes

Note: The results of this function are cached. See clearstatcache() for more details.

That’s a pretty big note. Don’t forget this one, since it can make your file_exists() behave unexpectedly — probably at production time 😉

Note that realpath() will return false if the file doesn’t exist. So if you’re going to absolutize the path and resolve symlinks anyway, you can just check the return value from realpath() instead of calling file_exists() first

I needed to measure performance for a project, so I did a simple test with one million file_exists() and is_file() checks. In one scenario, only seven of the files existed. In the second, all files existed. is_file() needed 3.0 for scenario one and 3.3 seconds for scenario two. file_exists() needed 2.8 and 2.9 seconds, respectively. The absolute numbers are off course system-dependant, but it clearly indicates that file_exists() is faster.

file_exists() does NOT search the php include_path for your file, so don’t use it before trying to include or require.

Yes, include does return false when the file can’t be found, but it does also generate a warning. That’s why you need the @. Don’t try to get around the warning issue by using file_exists(). That will leave you scratching your head until you figure out or stumble across the fact that file_exists() DOESN’T SEARCH THE PHP INCLUDE_PATH.

file_exists() is vulnerable to race conditions and clearstatcache() is not adequate to avoid it.

The following function is a good solution:

function file_exists_safe ( $file ) if (! $fd = fopen ( $file , ‘xb’ )) return true ; // the file already exists
>
fclose ( $fd ); // the file is now created, we don’t need the file handler
return false ;
>
?>

The function will create a file if non-existent, following calls will fail because the file exists (in effect being a lock).

IMPORTANT: The file will remain on the disk if it was successfully created and you must clean up after you, f.ex. remove it or overwrite it. This step is purposely omitted from the function as to let scripts do calculations all the while being sure the file won’t be «seized» by another process.

NOTE: This method fails if the above function is not used for checking in all other scripts/processes as it doesn’t actually lock the file.
FIX: You could flock() the file to prevent that (although all other scripts similarly must check it with flock() then, see https://www.php.net/manual/en/function.flock.php). Be sure to unlock and fclose() the file AFTER you’re done with it, and not within the above function:

function create_and_lock ( $file ) if (! $fd = fopen ( $file , ‘xb’ )) return false ;
>
if (! flock ( $fd , LOCK_EX | LOCK_NB )) < // may fail for other reasons, LOCK_NB will prevent blocking
fclose ( $fd );
unlink ( $file ); // clean up
return false ;
>
return $fd ;
>

if ( $lock = create_and_lock ( «foo.txt» )) // do stuff
flock ( $fd , LOCK_UN ); // unlock
fclose ( $fd ); // close
>
?>

SEE ALSO: https://linux.die.net/man/2/open about O_CREAT|O_EXCL (which is used with the ‘x’ modifier for fopen()) and problems with NFS

In response to seejohnrun’s version to check if a URL exists. Even if the file doesn’t exist you’re still going to get 404 headers. You can still use get_headers if you don’t have the option of using CURL..

$file = ‘http://www.domain.com/somefile.jpg’;
$file_headers = @get_headers($file);
if($file_headers[0] == ‘HTTP/1.1 404 Not Found’) $exists = false;
>
else $exists = true;
>

I was having problems with the file_exists when using urls, so I made this function:

function file_exists_2 ( $filePath )
return ( $ch = curl_init ( $filePath )) ? @ curl_close ( $ch ) || true : false ;
>
?>

Cheers!

If you are trying to access a Windows Network Share you have to configure your WebServer with enough permissions for example:

You will get an error telling you that the pathname doesnt exist this will be because Apache or IIS run as LocalSystem so you will have to enter to Services and configure Apache on «Open a session as» Create a new user that has enough permissions and also be sure that target share has the proper permissions.

Hope this save some hours of research to anyone.

With PHP 7.0 on Ubuntu 17.04 and with the option allow_url_fopen=On, file_exists() returns always false when trying to check a remote file via HTTP.

returns always «missing», even for an existing URL.

I found that in the same situation the file() function can read the remote file, so I changed my routine in

This is clearly a bit slower, especially if the remote file is big, but it solves this little problem.

here a function to check if a certain URL exist:
function url_exists ( $url ) $a_url = parse_url ( $url );
if (!isset( $a_url [ ‘port’ ])) $a_url [ ‘port’ ] = 80 ;
$errno = 0 ;
$errstr = » ;
$timeout = 30 ;
if(isset( $a_url [ ‘host’ ]) && $a_url [ ‘host’ ]!= gethostbyname ( $a_url [ ‘host’ ])) $fid = fsockopen ( $a_url [ ‘host’ ], $a_url [ ‘port’ ], $errno , $errstr , $timeout );
if (! $fid ) return false ;
$page = isset( $a_url [ ‘path’ ]) ? $a_url [ ‘path’ ]: » ;
$page .= isset( $a_url [ ‘query’ ])? ‘?’ . $a_url [ ‘query’ ]: » ;
fputs ( $fid , ‘HEAD ‘ . $page . ‘ HTTP/1.0’ . «\r\n» . ‘Host: ‘ . $a_url [ ‘host’ ]. «\r\n\r\n» );
$head = fread ( $fid , 4096 );
fclose ( $fid );
return preg_match ( ‘#^HTTP/.*\s+[200|302]+\s#i’ , $head );
> else return false ;
>
>
?>

in my CMS, I am using it with those lines:
if(!isset( $this -> f_exist [ $image ][ ‘exist’ ]))
if( strtolower ( substr ( $fimage , 0 , 4 )) == ‘http’ || strtolower ( substr ( $fimage , 0 , 4 )) == ‘www.’ ) if( strtolower ( substr ( $image , 0 , 4 )) == ‘www.’ ) $fimage = ‘http://’ . $fimage ;
$image = ‘http://’ . $image ;
>
$this -> f_exist [ $image ][ ‘exist’ ] = $this -> url_exists ( $fimage ); //for now
> else $this -> f_exist [ $image ][ ‘exist’ ] = ( $fimage != » && file_exists ( $fimage ) && is_file ( $fimage ) && is_readable ( $fimage ) && filesize ( $fimage )> 0 );
>
>
?>

I wrote this little handy function to check if an image exists in a directory, and if so, return a filename which doesnt exists e.g. if you try ‘flower.jpg’ and it exists, then it tries ‘flower[1].jpg’ and if that one exists it tries ‘flower[2].jpg’ and so on. It works fine at my place. Ofcourse you can use it also for other filetypes than images.

function imageExists ( $image , $dir )

Источник

stream_resolve_include_path

Resolve filename against the include path according to the same rules as fopen() / include .

Parameters

Return Values

Returns a string containing the resolved absolute filename, or false on failure.

Examples

Example #1 stream_resolve_include_path() example

The above example will output something similar to:

string(22) "/var/www/html/test.php"

User Contributed Notes 5 notes

In case you’re running a version of PHP that doesn’t have this function.

if (!function_exists(‘stream_resolve_include_path’)) /**
* Resolve filename against the include path.
*
* stream_resolve_include_path was introduced in PHP 5.3.2. This is kinda a PHP_Compat layer for those not using that version.
*
* @param Integer $length
* @return String
* @access public
*/
function stream_resolve_include_path($filename)
$paths = PATH_SEPARATOR == ‘:’ ?
preg_split(‘#(? explode(PATH_SEPARATOR, get_include_path());
foreach ($paths as $prefix) $ds = substr($prefix, -1) == DIRECTORY_SEPARATOR ? » : DIRECTORY_SEPARATOR;
$file = $prefix . $ds . $filename;

if (file_exists($file)) return $file;
>
>

stream_resolve_include_path() seems to cache it’s output. After I renamed a file, I had to restart Apache for stream_resolve_include_path() to not return non-existing file name. This was on Windows.

In some case like this, you can’t use `realpath()` or `file_exists()` without resolve its path.

file.php
subfolder/
..|- included.php
..|- subfolder/
. |- another-included.php

file.php contents:
«`
var_dump ( file_exists ( ‘subfolder/included.php’ )); // true
include ‘subfolder/included.php’ ;
?>
«`

subfolder/included.php contents:
«`
var_dump ( file_exists ( ‘subfolder/another-included.php’ )); // false but the file is really exists.
var_dump ( file_exists ( stream_resolve_include_path ( ‘subfolder/another-included.php’ ))); // with `stream_resolve_include_path()` function, it returns true now.
include ‘subfolder/another-included.php’ ; // working fine, no errors.
?>
«`

subfolder/subfolder/another-included.php contents:
«`
echo ‘Hello world’ ;
?>
«`

It really behaves like `include` and will only resolve the filename against the include-path, if the path is relative. It makes not much sense to resolve already absolute pathnames anyway.

This seems to be a great alternative to file_exists.

if( stream_resolve_inlcude_path(__DIR__.’/som-file.php’) !== false)

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