(PHP 4, PHP 5, PHP 7, PHP 8)
touch — Establece el momento de acceso y modificación de un archivo
Intenta establecer los momentos de acceso y modificación del archivo nombrado por el
parámetro filename al valor dado en
time.
Observe que el momento de acceso se modifica siempre, sin importar el número
de parámetros.
Si el archivo no existe, será creado.
filenameEl nombre del archivo que va a ser afectado.
time
El momento de afectación. Si time no es proporcionado,
se usa la hora actual del sistema.
atime
Si está presente, el momento de acceso del nombre de archivo dado se establece
al valor de atime. De otro modo, se establece al
valor pasado al parámetro time.
Si ninguno está presente, se usa el momento actual del sistema.
| Versión | Descripción |
|---|---|
| 5.3.0 | Se hizo posible cambiar el momento de modificación de un directorio bajo Windows. |
Ejemplo #1 Ejemplo de touch()
<?php
if (touch($nombre_archivo)) {
echo 'El momento de modificación de ' . $nombre_archivo . ' ha sido cambiada a la hora actual';
} else {
echo 'Lo siento, no se pudo cambiar el momento de modificación de ' . $nombre_archivo;
}
?>
Ejemplo #2 touch() usando el parámetro time
<?php
// Este es el momento afectado, lo estableceremos a una hora antes
$momento = time() - 3600;
// Afectar el archivo
if(!touch('archivo.txt', $momento)) {
echo 'Lo sieno, algo fue mal...';
} else {
echo 'Archivo afectado con éxito';
}
?>Nota:
Observe que el tiempo de resolución quizá varia según el sistema de ficheros.
Antes de PHP 5.3.0 no era posible cambiar el momento de modificación de un directorio con esta función bajo Windows.
Note that when PHP is called by f.e. apache or nginx instead of directly from the command line, touch() will not prefix the location of the invoking script, so the supplied filename must contain an absolute path.
With script started from /home/user/www, this will not touch "/home/user/www/somefile":
<?php
touch( 'somefile' );
?>
But this will:
<?php
touch( __DIR__ . '/somefile' );
?>Update the access time without updating the modified time:
Unix command: touch -a filename
PHP: touch(filename, date('U', filemtime(filename)), time())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,$time);At least on Linux, touch will not change the time on a symlink itself, but on the file/directory it points to. The only way to work around this is to unlink the symlink, then recreate it.
It took a bit of searching to discover this. The OS itself provides no way to do it. Many people wondered why anyone would want to do this. I use symlinks inside a web tree to point to files outside the web tree. After a certain length of time has passed, I want the symlinks to die, so the files cannot be successfully hotlinked.To touch a file without being owner, it is much easier:
<?php
function touchFile($file) {
fclose(fopen($file, 'a'));
}
?>I needed to use this to touch the /etc/cron.d directory when I updated some files in there. I know the docs say this isn't necessary, but I'm finding that i need to do it in order form my changes to be picked up quickly.
I ran into the permissions error as well and I found that using chmod 777 /etc/cron.d does the trick.
So, you should be able to use the PHP touch function on a directory that has open write access.
Of course, this isn't the most secure approach, but in our application it's not a big deal for that folder to not be super secure.Actually, Glen is right, PHP won't touch if it is not the current owner of the file, even if the directory and files are writeable by the PHP user.Only way to change modification date in catalogue is to create file in via touch() and dalete it with unlink():
<?php
$dir = 'temp';
$files1 = scandir($dir);
$files1 = array_slice($files1, 2);
foreach ($files1 as $key => $val)
{
if (!is_dir($val)) continue;
if (!touch($val))
{
touch($val . "/plik.txt");
unlink($val . "/plik.txt");
}
}
?>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 itNeat 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;
}I have found out that setting a negative *mtime* deletes the file. The following code always deletes the file at $path while $touch returns true.
<?php
$path = '/folder/file';
$timestamp = -1;
$touch = touch($path, $timestamp);
?>
Running PHP 7.4.5A better explanation:
For file $file and UNIX time stored in vars $access and $modified
- change only access time
\touch($file, \filemtime($file), $access);
- change only modified time
\touch($file, $modified, \fileatime($file));
- change both access and modified time
\touch($file, $modified, $access);
Seeing the results:
//use a session cookie stored in a custom folder
$file = '/var/www/test_com/session/sess_qfn587cudfpgsijm1bs4d81s75';
echo 'stats for sess_qfn587cudfpgsijm1bs4d81s75<br/>';
\clearstatcache();
echo 'access: '.\date("Y-m-d H:i:s", \fileatime($file)).'<br/>';
echo 'modified: '.\date("Y-m-d H:i:s", \filemtime($file)).'<br/>';
echo 'change access to now, modified +1 hour<br/>';
\touch($x, \filemtime($file)+3600, time());
\clearstatcache();
echo 'access: '.\date("Y-m-d H:i:s", \fileatime($file)).'<br/>';
echo 'modified: '.\date("Y-m-d H:i:s", \filemtime($file)).'<br/>';
Notice the double call to clearstatcache()!