chdir

(PHP 4, PHP 5)

chdir — Change directory

Description

bool chdir ( string $directory )

Changes PHP's current directory to directory.

Parameters

directory: The new current directory

Return Values

Returns TRUE on success or FALSE on failure.

Errors/Exceptions

Throws an error of level E_WARNING on failure.

Examples

Example #1 chdir() example


<?php

// current directory
echo getcwd() . "\n";

chdir('public_html');

// current directory
echo getcwd() . "\n";

?>

The above example will output something similar to:

/home/vincent
/home/vincent/public_html

Notes

Note: When safe mode is enabled, PHP checks whether the directory in which the script is operating has the same UID (owner) as the script that is being executed.


When changing dir's under windows environments:





<?php


$path="c:\temp"';


chdir($path);


/* getcwd() gives you back "c:\temp" */





$path="c:\temp\"';


chdir($path);


/* getcwd() gives you back "c:\temp\" */


?>





to work around this inconsistency


doing a chdir('.') after the chdir always gives back "c:\temp"

andy dot clark at dial dot pipex dot com 21-Aug-2006 08:10


This only changes the directory for PHP, the output directory stays the same. If you are trying to access images from a relative path and you use the following then it will fail to render the image:



chdir ('images');

if (file_exists('php.gif')) 

{

echo '<html>';

echo '<body>';

echo '<img src="php.gif">';

echo '</body></html>';

}



//However, it is possible to use the <base> tag in the header to change the directory for the resulting HTML, as you can see however this requires you to put the full path in place.



chdir ('images');

if (file_exists('php.gif')) 

{

echo '<html>';

echo '<head><base href = "http://uk.php.net/images/"></head>';

echo '<body>';

echo '<img src="php.gif">';

echo '</body></html>';

}

herwin at snt dot utwente dot nl 17-Aug-2006 11:58


When using PHP safe mode and trying to change to a dir that is not accessible due to the safe mode restrictions, the function simply fails without generating any kind of error message.



(Tested in PHP 4.3.10-16, Debian Sarge default)

jeprubio _At_ gmail dot com 27-May-2005 12:25


If you run this script when $sym_dir is a symbolic link to a directory:

  echo getcwd()."\n";

  chdir ($sym_dir);

  chdir ('../');

  echo getcwd()."\n";



It returns for example:

  /dades/loc/real/mapes/navteq/anloc

  /mapes/anloc



It will not return to the previous directory, it returns to the parent of the real directory where it links the symbolic link.



It's not necessary a bug but I think it's important to have present this.



It could be solved saving the current directory and then returning to it. For example:

  $cwd = getcwd();

  echo getcwd()."\n";

  chdir ($sym_dir);

  chdir ($cwd);

  echo getcwd()."\n";



It returns:

  /dades/loc/real/mapes/navteq/anloc

  /dades/loc/real/mapes/navteq/anloc



Have fun :)

-------

   Josep Rubio (Anloc S.L. www.anloc.net)

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