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Last updated: Fri, 01 Aug 2008

touch

(PHP 4, PHP 5)

touch — Sets access and modification time of file

Descrierea

bool touch ( string $filename [, int $time [, int $atime ]] )

Attempts to set the access and modification times of the file named in the filename parameter to the value given in time . Note that the access time is always modified, regardless of the number of parameters.

If the file does not exist, it will be created.

Parametri

filename: The name of the file being touched.
time: The touch time. If time is not supplied, the current system time is used.
atime: If present, the access time of the given filename is set to the value of atime

Valorile întroarse

Întoarce valoarea TRUE în cazul succesului sau FALSE în cazul eşecului.

Exemple

Example #1 touch() example


<?php
if (touch($FileName)) {
    echo "$FileName modification time has been changed to present time";
} else {
    echo "Sorry, could not change modification time of $FileName";
}
?>

Note

Avertizare

It is not currently possible to change the modification time of a directory with this function under Windows.

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tmpfile

Last updated: Fri, 01 Aug 2008

add a note User Contributed Notes
touch

Bess E. R. Wisser
26-Aug-2008 04:20


"Glen: In unix on the command-line, you can touch files you don't own - but like other comments on this page state - PHP's built in touch won't work."



No, you can not modify files you don't have write access to in a multi-user environment, ever, under any circumstances. The reason why you fail to do this "in PHP" is because your httpd is most likely running as a "shared" setup, running as nobody/nobody, and your user's files aren't world-writable, and they are not owned by nobody/nobody. Change your required files to be world-writable and you can touch() them, and more.

Radon8472
08-Aug-2008 08:07


Important info:



touch() used on a directory always returns FALSE and prints "Permission denied" on NTFS and FAT Filesystem (tested on winXP).

Jeff
27-Jun-2008 03:29


I've been trying to set a filemtime into the future with touch() on PHP5.



It seems touch $time has a future limit around 1000000 seconds (11 days or so). Beyond this point it reverts to a previous $time.



It doesn't make much sense but I could save you hours of time.



$time = time()+1500000;

touch($cachedfile,$time);

Glen
19-Oct-2007 04:01


In unix on the command-line, you can touch files you don't own - but like other comments on this page state - PHP's built in touch won't work.



I simple alternative (on unix):



<?php



    function touch_it_good($filename)

    {

        exec("touch {$filename}");

    }

?>

ilrazziatore85 AT yahoo DOT it
21-May-2007 11:10


Feathern wrote a little script for fetching files from a directory after a certain date.

However the if statement (line 8) should be:



if(($test[2] > 2002) || (($test[2] = 2002) && ($test[0] > 6)) || (($test[2] = 2002) && ($test[0] = 6) && ($test[1] > 17))){

        echo $filelist[$i]."\r\n";

}



Otherwise the script won't fetch lots of files it should.



(In the example given, it should fetch all the files created after 06/17/2002, but the original script would miss files created 03/18/2003 or 11/01/2004)

seocab at rit dot edu
01-Apr-2007 12:09


The script for modifying the access time without modifying the modified time is overly complicated:



<? touch($filename, date('U', filemtime($filename)), time()); ?>



Since filemtime returns a UNIX timestamp, there is no need to call date('U') so the script could be simplified to:



<? touch($filename,filemtime($filename),time()); ?>

Charles Belov
19-Jul-2006 09:10


Update the access time without updating the modified time:



Unix command: touch -a filename



PHP: touch(filename, date('U', filemtime(filename)), time())

spam at webmastersguide dot com
01-Sep-2005 08:09


If you're going to go around deleting (unlinking) files

that you don't own just in order to change the modification

time on the file, you darn well better chown() the file 

back to it's original ownership after you are done and

chmod() it back to it's correct permissions.  Otherwise 

you will almost certainly break things.  Additionally the

code listed for touch()ing a file you don't own should 

set the file creation time back to it's original time if 

what is wanted is to just change the modification time.

Also, the code listed will break things if there is an i/o 

error such as disk full or too many files in the directory.

Here's how the code SHOULD be written:



Create the new file FIRST, rather than last, with a different

name such as $file.tmp.

Read the ownership, permissions, and creation time of the old file.

Set permissions and creation time of the new file the same as the old.

Rename the new file to the name of the old.

chown() the new file to the user that owned the file it's replacing.



Please be careful adding to the documentation if you've 

never taken programming 101.

rf_public at yahoo dot co dot uk
26-Jul-2005 03:19


Note: the script to touch a file you don't own will change it's owner so ensure permissions are correct or you could lose access to it

guy at forster design dot com
12-May-2005 06:42


Here's a little workaround that allows the PHP user to touch a file it doesn't own:



<?php



    $target_file = "/path/to/file/filename.txt"; //system filepath to your file

    $file_content = implode("",file($target_file));

    @unlink($target_file);

    if($savetofile = fopen($target_file, "w")) {

        fputs($savetofile, $file_content);

        fclose($savetofile);

    }

    $new_date = strtotime("23 April 2005"); // set the required date timestamp here

    touch($target_file,$new_date);

 

?>



Of course, PHP needs to have write access to the folder containing the file you want to touch, but that should be easy to arrange.

feathern at yahoo dot com
14-Aug-2002 06:31


Neat little script that will give you a list of all modified files in a certain folder after a certain date:



$filelist = Array();

$filelist = list_dir("d:\\my_folder");

for($i=0;$i<count($filelist);$i++){

    $test = Array();

    $test = explode("/",date("m/d/Y",filemtime($filelist[$i])));

//example of files that are later then

//06/17/2002

    if(($test[2] > 2001) && ($test[1] > 16) && ($test[0] > 5)){

        echo $filelist[$i]."\r\n";

    }

    clearstatcache();

}

function list_dir($dn){

    if($dn[strlen($dn)-1] != '\\') $dn.='\\';

    static $ra = array();

    $handle = opendir($dn);

    while($fn = readdir($handle)){

        if($fn == '.' || $fn == '..') continue;

        if(is_dir($dn.$fn)) list_dir($dn.$fn.'\\');

        else $ra[] = $dn.$fn;

    }

    closedir($handle);

    return $ra;

}

emilebosch at hotmail dot com
07-Oct-2001 06:41


To spare you ppl couple of hours of valuable time, you can only TOUCH a file that you own! Usually PHP is *nobody* 


Warm regards,


Emile Bosch

master at dreamphp dot com
16-May-2001 02:23


$filename = "test.dat";


if (!file_exists($filename)) {


  touch($filename); // Create blank file


  chmod($filename,0666);


}

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tmpfile

Last updated: Fri, 01 Aug 2008