stat

(PHP 4, PHP 5, PHP 7, PHP 8)

stat — Proporciona información sobre un fichero

Descripción

stat(string $filename): array|false

Proporciona información sobre el fichero filename. Si filename es un enlace simbólico, la información proviene del fichero en sí, y no del enlace simbólico. Antes de PHP 7.4.0, en Windows NTS compila los valores estáticos size, atime, mtime y ctime desde los enlaces simbólicos, en este caso.

lstat() es idéntico a stat() excepto que la información se basa en el enlace simbólico.

Parámetros

filename: La ruta al fichero.

Valores devueltos

**Formato del resultado de **stat()** y fstat()**
Número	Nombre	Descripción
0	dev	volumen (***)
1	ino	Número de inodo (****)
2	mode	derechos de acceso al inodo *****
3	nlink	número de enlaces
4	uid	userid del propietario (*)
5	gid	groupid del propietario (*)
6	rdev	tipo de volumen, si el volumen es un inodo
7	size	tamaño en bytes
8	atime	fecha del último acceso (timestamp Unix)
9	mtime	fecha de la última modificación (timestamp Unix)
10	ctime	fecha del último cambio de inodo (timestamp Unix)
11	blksize	tamaño de bloque (**)
12	blocks	número de bloques de 512 bytes asignados (**)

* - En Windows, esto siempre será 0.

** - Solo en sistemas que soportan el tipo st_blksize. Los otros sistemas (ej. Windows) devuelven -1.

*** - En Windows, desde PHP 7.4.0, será el número de serie del volumen que contiene el fichero, que será un entero 64-bit sin signo que puede desbordarse. Anteriormente, era la representación numérica de la letra del volumen (ej. 2 para C:) para la función stat(), y 0 para la función lstat().

**** - En Windows, desde PHP 7.4.0, es el identificador asociado con el fichero, que será un entero 64-bit sin signo que puede desbordarse. Anteriormente, siempre era 0.

***** En Windows, el bit de permiso de escritura se define en función del atributo de solo lectura del fichero, y el mismo valor se reporta para todos los usuarios, grupo y propietario. El ACL no se tiene en cuenta, a diferencia de is_writable().

El valor de mode contiene información leída por varias funciones. Cuando se escribe en octal, comenzando por la derecha, los tres primeros dígitos son devueltos por chmod(). El siguiente dígito es ignorado por PHP. Los dos siguientes dígitos indican el tipo de fichero:

**Los tipos de ficheros `mode`**
`mode` en octal	Significado
`0140000`	socket
`0120000`	enlace simbólico
`0100000`	fichero regular
`0060000`	dispositivo de bloque
`0040000`	directorio
`0020000`	dispositivo de carácter
`0010000`	FIFO (un tubo nombrado)

Por ejemplo, un fichero regular podría ser 0100644 y un directorio podría 0040755.

En caso de error, stat() devuelve false.

Nota: Como el tipo entero de PHP es firmado y que muchas plataformas utilizan enteros de 32 bits, algunas funciones relacionadas con el sistema de archivos pueden retornar resultados extraños para archivos de tamaño superior a 2 Go.

Errores/Excepciones

Si ocurre un error, se emite una advertencia de tipo E_WARNING.

Historial de cambios

Versión	Descripción
7.4.0	En Windows, el número del volumen es ahora el número de serie que contiene el fichero, y el número de inodo es el identificador asociado con el fichero.
7.4.0	Los valores estáticos `size`, `atime`, `mtime` y `ctime` de los enlaces simbólicos son siempre los de la meta. Esto no era así previamente para los builds NTS en Windows.

Ejemplos

Ejemplo #1 Ejemplo con stat()

<?php
/* Obtención de la información */
$stat = stat('C:\php\php.exe');

/*
 * Mostrar la fecha y hora del acceso a este fichero,
 * idéntico a la llamada a la función fileatime()
 */
echo 'Fecha y hora de acceso : ' . $stat['atime'];

/*
 * Mostrar la fecha y hora de modificación del fichero,
 * idéntico a la llamada a la función filemtime()
 */
echo 'Fecha y hora de modificación : ' . $stat['mtime'];

/* Mostrar el número del dispositivo */
echo 'Número del dispositivo : ' . $stat['dev'];
?>

Ejemplo #2 Uso de la información obtenida de stat() junto con la función touch()

<?php
/* Obtención de la información de la función stat */
$stat = stat('C:\php\php.exe');

/* ¿Ha fallado el acceso a la información? */
if (!$stat) {
    echo 'La llamada a stat() ha fallado...';
} else {
    /*
     * Queremos que la fecha y hora de acceso sea una
     * semana después de la fecha actual.
     */
    $atime = $stat['atime'] + 604800;

    /* Modificamos el fichero */
    if(!touch('some_file.txt', time(), $atime)) {
        echo 'Fallo al llamar a la función touch()...';
    } else {
        echo 'La llamada a touch() ha tenido éxito...';
    }
}
?>

Notas

Nota:
Tenga en cuenta que la precisión temporal puede variar según el sistema de archivos utilizado.

Nota: Los resultados de esta función están en caché. Véase la función clearstatcache() para más detalles.

Sugerencia

A partir de PHP 5.0.0, esta función también puede ser utilizada con algunos protocolos url. Lea Protocolos y Envolturas soportados para conocer los protocolos que soportan la familia de funcionalidades de stat().

Ver también

lstat() - Devuelve información sobre un fichero o un enlace simbólico
fstat() - Lee las informaciones sobre un fichero a partir de un puntero de fichero
filemtime() - Lee la fecha de última modificación del fichero
filegroup() - Leer el nombre del grupo
SplFileInfo

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User Contributed Notes 18 notes

down

webmaster at askapache dot com ¶

16 years ago

down

webmaster at askapache dot com ¶

11 years ago

On GNU/Linux you can retrieve the number of currently running processes on the machine by doing a stat for hard links on the '/proc' directory like so:

$ stat -c '%h' /proc
118

You can do the same thing in php by doing a stat on /proc and grabbing the [3] 'nlink' - number of links in the returned array.

Here is the function I'm using, it does a clearstatcache() when called more than once.

<?php

/**
 * Returns the number of running processes
 *
 * @link http://php.net/clearstatcache
 * @link http://php.net/stat  Description of stat syntax.
 * @author http://www.askapache.com/php/get-number-running-proccesses.html
 * @return int
 */
function get_process_count() {
  static $ver, $runs = 0;
  
  // check if php version supports clearstatcache params, but only check once
  if ( is_null( $ver ) )
    $ver = version_compare( PHP_VERSION, '5.3.0', '>=' );
 
  // Only call clearstatcache() if function called more than once */
  if ( $runs++ > 0 ) { // checks if $runs > 0, then increments $runs by one.
    
    // if php version is >= 5.3.0
    if ( $ver ) {
      clearstatcache( true, '/proc' );
    } else {
      // if php version is < 5.3.0
      clearstatcache();
    }
  }
  
  $stat = stat( '/proc' );
 
  // if stat succeeds and nlink value is present return it, otherwise return 0
  return ( ( false !== $stat && isset( $stat[3] ) ) ? $stat[3] : 0 );
}

?>

Example #1 get_process_count() example

<?php
$num_procs = get_process_count();
var_dump( $num_procs );
?>

The above example will output:

int(118)

Which is the number of processes that were running.

down

admin at smitelli dot com ¶

19 years ago

There's an important (yet little-known) problem with file dates on Windows and Daylight Savings. This affects the 'atime' and 'mtime' elements returned by stat(), and it also affects other filesystem-related functions such as fileatime() and filemtime().

During the winter months (when Daylight Savings isn't in effect), Windows will report a certain timestamp for a given file. However, when summer comes and Daylight Savings starts, Windows will report a DIFFERENT timestamp! Even if the file hasn't been altered at all, Windows will shift every timestamp it reads forward one full hour during Daylight Savings.

This all stems from the fact that M$ decided to use a hackneyed method of tracking file dates to make sure there are no ambiguous times during the "repeated hour" when DST ends in October, maintain compatibility with older FAT partitions, etc. An excellent description of what/why this is can be found at http://www.codeproject.com/datetime/dstbugs.asp

This is noteworthy because *nix platforms don't have this problem. This could introduce some hard-to-track bugs if you're trying to move scripts that track file timestamps between platforms.

I spent a fair amount of time trying to debug one of my own scripts that was suffering from this problem. I was storing file modification times in a MySQL table, then using that information to see which files had been altered since the last run of the script. After each Daylight Savings change, every single file the script saw was considered "changed" since the last run, since all the timestamps were off by +/- 3600 seconds.

This one-liner is probably one of the most incorrect fixes that could ever be devised, but it's worked flawlessly in production-grade environments... Assuming $file_date is a Unix timestamp you've just read from a file:

<?php
    if (date('I') == 1) $file_date -= 3600;
?>

That will ensure that the timestamp you're working with is always consistently reported, regardless of whether the machine is in Daylight Savings or not.

down

mail4rico at gmail dot com ¶

17 years ago

In response to the note whose first line is:
Re note posted by "admin at smitelli dot com"

I believe you have the conversion backwards. You should add an hour to filemtime if the system is in DST and the file is not. Conversely, you should subtract an hour if the file time is DST and the current OS time is not.

Here's a simplified, corrected version:
<?php
    function getmodtime($file) { //returns the time a file was modified.
        $mtime = filemtime($file);
        //date('I') returns 1 if DST is on and 0 if off.
        $diff = date('I')-date('I', $mtime);
        //diff =  0 if file-time and os-time are both in the same DST setting
        //diff =  1 if os is DST and file is not
        //diff = -1 if file is DST and os is not
        return $mtime + $diff*3600;
    }
?>
Here's a test:
<?php
    //create two dummy files:
    $file0 = 'file1.txt';
    $file1 = 'file2.txt';
    file_put_contents($file0, '');
    file_put_contents($file1, '');
    
    $time0=strtotime('Jan 1 2008 10:00'); echo 'Date0 (ST): ' . date(DATE_COOKIE, $time0)."\n";
    $time1=strtotime('Aug 1 2008 10:00'); echo 'Date1 (DT): ' . date(DATE_COOKIE, $time1)."\n";
    touch($file0, $time0); //set file0 to Winter (Non-DST)
    touch($file1, $time1); //set file1 to Summer (DST)
    
    $ftime0 = filemtime($file0);
    $ftime1 = filemtime($file1);
    echo "\nUncorrected: \n";
    echo 'File 0: ' . ($ftime0-$time0) ."\n";
    echo 'File 1: ' . ($ftime1-$time1) ."\n";
    //if your system adjusts for DST, then _one_ of the above should be 3600 or -3600, depending on the time of year
    
    $ftime0 = getmodtime($file0); //use filemtime correction
    $ftime1 = getmodtime($file1); //use filemtime correction
    echo "\nCorrected: \n";
    echo 'File 0: ' . ($ftime0-$time0) ."\n";
    echo 'File 1: ' . ($ftime1-$time1) ."\n";
    //both of the corrected values output should be 0.
?>

Output:
------------------------------
(when run in summer)
------------------------------
Date0 (ST): Tuesday, 01-Jan-08 10:00:00 EST
Date1 (DT): Friday, 01-Aug-08 10:00:00 EDT

Uncorrected: 
File 0: -3600
File 1: 0

Corrected: 
File 0: 0
File 1: 0
------------------------------
(when run in winter--dates omitted)
------------------------------
Uncorrected: 
File 0: 0
File 1: 3600

Corrected: 
File 0: 0
File 1: 0

In response to Re note posted by "admin at smitelli dot com",  your version below gives the following output when substituted into my test:
------------------------------
(when run in summer--dates omitted)
------------------------------
Uncorrected: 
File 0: -3600
File 1: 0

Corrected: 
File 0: -7200
File 1: 0
------------------------------
You can see that the operation is the opposite of what it should be.

down

com dot gmail at algofoogle ¶

19 years ago

Re note posted by "salisbm at hotmail dot com":

S_IFDIR is not a single-bit flag. It is a constant that relies on the "S_IFMT" bitmask. This bitmask should be applied to the "mode" parameter before comparing with any of the other "S_IF..." constants, as indicated by stat.h:

#define S_ISDIR(m)  (((m) & S_IFMT) == S_IFDIR)

That is, this approach is incorrect:

<?php
define('S_IFDIR',040000);
if ($mode & S_IFDIR)
{
  /*
    incorrect!
    format could be S_IFDIR, but also
    S_IFBLK, S_IFSOCK, or S_IFWHT.
  */
}
?>

...and should instead be:

<?php
define('S_IFMT',0170000);
define('S_IFDIR',040000);
if (S_IFDIR == ($mode & S_IFMT)) {  /* ... */  }
?>

As pointed out by "svend at svendtofte dot com", however, there is also the "is_dir" function for this purpose, along with "is_file" and "is_link" to cover the most common format types...

down

ian at eiloart dot com ¶

25 years ago

Here's what the UNIX man page on stat has to say about the difference between a file change and  a file modification:



st_mtime  Time when data was last modified.  Changed by  the following  functions:   creat(),  mknod(), pipe(), utime(), and write(2).



st_ctime  Time when file status was last  changed.   Changed by  the  following  functions: chmod(), chown(), creat(), link(2), mknod(), pipe(), unlink(2), utime(), and write().



So a modification is a change in the data, whereas a change also happens if you modify file permissions and so on.

down

salisbm at hotmail dot com ¶

21 years ago

I was curious how I could tell if a file was a directory... so I found on http://www.hmug.org/man/2/stat.html the following information about the mode bits:
#define S_IFMT 0170000           /* type of file */
#define        S_IFIFO  0010000  /* named pipe (fifo) */
#define        S_IFCHR  0020000  /* character special */
#define        S_IFDIR  0040000  /* directory */
#define        S_IFBLK  0060000  /* block special */
#define        S_IFREG  0100000  /* regular */
#define        S_IFLNK  0120000  /* symbolic link */
#define        S_IFSOCK 0140000  /* socket */
#define        S_IFWHT  0160000  /* whiteout */
#define S_ISUID 0004000  /* set user id on execution */
#define S_ISGID 0002000  /* set group id on execution */
#define S_ISVTX 0001000  /* save swapped text even after use */
#define S_IRUSR 0000400  /* read permission, owner */
#define S_IWUSR 0000200  /* write permission, owner */
#define S_IXUSR 0000100  /* execute/search permission, owner */

Note that these numbers are in octal format.  Then, to check to see if the file is a directory, after calling fstat, I do:

if ($fstats[mode] & 040000)
  ... this must be a directory

down

JulieC ¶

18 years ago

The dir_size function provided by "marting.dc AT gmail.com" works great, except the $mas variable is not initialized.  Add:

   $mas = 0;

before the while() loop.

down

marting.dc AT gmail.com ¶

19 years ago

If you want to know a directory size, this function will help you:



<?php

function dir_size($dir)

{

    $handle = opendir($dir);

    

    while ($file = readdir($handle)) {

        if ($file != '..' && $file != '.' && !is_dir($dir.'/'.$file)) {

            $mas += filesize($dir.'/'.$file);

            } else if (is_dir($dir.'/'.$file) && $file != '..' && $file != '.') {

            $mas += dir_size($dir.'/'.$file);

        }

    }

    return $mas;

}

echo dir_size('DIRECTORIO').' Bytes';

?>

down

mao at nospam dot com ¶

20 years ago

If you have ftp (and the related sftp) protocols disabled on your remote server, it can be hard figuring out how to 'stat' a remote file. The following works for me:

<?php  

$conn = ssh2_connect($host, 22);
ssh2_auth_password($conn, $user, $password);
$stream = ssh2_exec($conn, "stat $fileName > $remotedest");
ssh2_scp_recv($conn, $remotedest, $localdest);
$farray = file($localdest);
print_r($farray);
?>

down

carlos [at] encore-lab [dot] com ¶

10 years ago

stat() may not work on mounted CIFS' in 32 bit systems if you do not specify the option noserverino when mounting. E.g:

mount -t cifs -o user="user",password="password",noserverino //example.local/share /mnt/mount-point

Other functions based on stat() data such as file time functions and is_dir() are affected the same way.

This happens because if you do not specify the option noserverino the remote inode may be 64 bit-based and thus the local system cannot handle it.

down

digitalaudiorock at hotmail dot com ¶

16 years ago

Regarding the stat() on files larger than 2GB on 32 bit systems not working, note that the behavior appears to differ between Linux and Windows.  Under Windows there's so way to know whether or not this failed.

It's been my experience that under Linux, performing a stat() on files that are too large for the integer size generates a warning and returns false.  However under Windows it silently truncates the high order bits of the size resulting in an incorrect number.  The only way you'd ever know it failed is in the event that the truncation happened to leave the sign bit on resulting in a negative size.  That is, there is _no_ reliable way to know it failed.

This is true of filesize() as well.

Tom

down

svend at svendtofte dot com ¶

20 years ago

To the note of how you can figure out if a file is a folder or not, there is also the handy "is_dir" function.

down

Ray.Paseur sometimes uses Gmail ¶

4 years ago

A good explanation of the "mode" bits is given here:
https://www.php.net/manual/en/function.fileperms.php

down

Hellhound ¶

17 years ago

To ignore index number or name specifics.. use:

list($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size, $atime, $mtime, $ctime, $blksize, $blocks)
         = lstat($directory_element);

down

Anonymous ¶

19 years ago

Re note posted by "admin at smitelli dot com"

I'm not sure how that can work all year round since you have to modify both opposing inside and outside DST based on the actual files themselves, as well as the current DST setting for the system.

e.g. using filemtime, same thing for stat.

<?php

$mtime = filemtime($file);

if (date('I') == 1) {
    // Win DST is enabled, adjust standard time 
    // files back to 'real' file UTC.
    if (date('I', $mtime) == 0) {
        $mtime -= 3600;
    }
} else {
    // Win DST is disabled, adjust daylight time 
    // files forward to 'real' file UTC.
    if (date('I', $mtime) == 1) {
        $mtime += 3600;
    }
}

echo gmdate('Y-m-d H:i:s', $mtime);

?>

Just another example of why 'not' to use windows in a server room.

down

-2

antonixyz at gmx dot net ¶

16 years ago

<?php

$stat = stat($filepath);

$mode = $stat[2];

?>

is identical to:

<?php $mode = fileperms($filepath); ?>



at least on my linux box.

down

-4

Anonymous ¶

20 years ago

If the 2GB limit is driving you crazy, you can use this complete hack.  use in place of filesize()

function file_size($file) {
  $size = filesize($file);
  if ( $size == 0)
    $size = exec("ls -l $file | awk '{print $5}'");
  return $size;
}

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