stat
(PHP 4, PHP 5)
stat — Возвращает информацию о файле
Описание
$filename
)
Собирает статистическую информацию о файле
filename. Если filename
является символической ссылкой, информация собирается о самом файле,
а не ссылке.
Функция lstat() индентична функции stat() за исключением того, что в данном случае она вернёт информацию о самой символической ссылке.
Список параметров
-
filename -
Путь к файлу.
Возвращаемые значения
| Числовой | Ассоциативный (начиная с PHP 4.0.6) | Описание |
|---|---|---|
| 0 | dev | номер устройства |
| 1 | ino | номер inode * |
| 2 | mode | режим защиты inode |
| 3 | nlink | количество ссылок |
| 4 | uid | userid владельца * |
| 5 | gid | groupid владельца * |
| 6 | rdev | тип устройства, если устройство inode |
| 7 | size | размер в байтах |
| 8 | atime | время последнего доступа (временная метка Unix) |
| 9 | mtime | время последней модификации (временная метка Unix) |
| 10 | ctime | время последнего изменения inode (временная метка Unix) |
| 11 | blksize | размер блока ввода-вывода файловой системы ** |
| 12 | blocks | количество используемых 512-байтных блоков ** |
** Доступен только на системах, поддерживающих тип st_blksize - другие системы (например, Windows) вернут -1.
В случае ошибки stat() возвращает FALSE.
Замечание: Так как тип integer в PHP является целым числом со знаком и многие платформы используют 32-х битные целые числа, то некоторые функции файловых систем могут возвращать неожиданные результаты для файлов размером больше 2ГБ.
Ошибки
В случае ошибки будет сгенерирована ошибка уровня E_WARNING.
Список изменений
| Версия | Описание |
|---|---|
| 4.0.6 | Кроме возможности получения доступа к любому атрибуту в числовом массиве, его можно также получить по ассоциативному ключу, который указан напротив каждого параметра. |
Примеры
Пример #1 Пример использования stat()
<?php
/* Получаем статистику файла */
$stat = stat('C:\php\php.exe');
/*
* Выводим последнее время доступа к файлу, это тоже самое, что и
* вызов fileatime()
*/
echo 'Последнее время доступа: ' . $stat['atime'];
/*
* Выводим время изменения файла, это тоже самое, что и
* вызов filemtime()
*/
echo 'Время изменения: ' . $stat['mtime'];
/* Выводим номер устройства */
echo 'Номер устройства: ' . $stat['dev'];
?>
Пример #2 Использование информации из stat() вместе с touch()
<?php
/* Получаем статистику файла */
$stat = stat('C:\php\php.exe');
/* Удалось получить эту статистику? */
if (!$stat) {
echo 'вызов stat() не удался...';
} else {
/*
* Мы хотим увеличить время последнего доступа к файлу
* на 1 неделю вперед.
*/
$atime = $stat['atime'] + 604800;
/* Касаемся файла */
if (!touch('some_file.txt', time(), $atime)) {
echo 'Не удалось коснуться файла...';
} else {
echo 'touch() выполнился успешно...';
}
}
?>
Примечания
Замечание:
Учтите, что обработка времени может отличаться в различных файловых системах.
Замечание: Результаты этой функции кэшируются. Более подробную информацию смотрите в разделе clearstatcache().
Начиная с PHP 5.0.0, эта функция также может быть использована с некоторыми обертками url. Список оберток, поддерживаемых семейством функций stat(), смотрите в Поддерживаемые протоколы и обработчики (wrappers).
Смотрите также
- lstat() - Возвращает информацию о файле или символической ссылке
- fstat() - Получает информацию о файле используя открытый файловый указатель
- filemtime() - Возвращает время последнего изменения файла
- filegroup() - Получает идентификатор группы файла
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с файловой системой
- Функции для работы с файловой системой
- basename
- chgrp
- chmod
- chown
- clearstatcache
- copy
- delete
- dirname
- disk_free_space
- disk_total_space
- diskfreespace
- fclose
- feof
- fflush
- fgetc
- fgetcsv
- fgets
- fgetss
- file_exists
- file_get_contents
- file_put_contents
- file
- fileatime
- filectime
- filegroup
- fileinode
- filemtime
- fileowner
- fileperms
- filesize
- filetype
- flock
- fnmatch
- fopen
- fpassthru
- fputcsv
- fputs
- fread
- fscanf
- fseek
- fstat
- ftell
- ftruncate
- fwrite
- glob
- is_dir
- is_executable
- is_file
- is_link
- is_readable
- is_uploaded_file
- is_writable
- is_writeable
- lchgrp
- lchown
- link
- linkinfo
- lstat
- mkdir
- move_uploaded_file
- parse_ini_file
- parse_ini_string
- pathinfo
- pclose
- popen
- readfile
- readlink
- realpath_cache_get
- realpath_cache_size
- realpath
- rename
- rewind
- rmdir
- set_file_buffer
- stat
- symlink
- tempnam
- tmpfile
- touch
- umask
- unlink
Коментарии
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.
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
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.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;
}
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($farray);
?>
Re note posted by "salisbm at hotmail dot com":
S_IFDIR is not a single-bit flag. It is a constant that relies on the "S_IFMT" bitmask. This bitmask should be applied to the "mode" parameter before comparing with any of the other "S_IF..." constants, as indicated by stat.h:
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
That is, this approach is incorrect:
<?php
define('S_IFDIR',040000);
if ($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 == ($mode & S_IFMT)) { /* ... */ }
?>
As pointed out by "svend at svendtofte dot com", however, there is also the "is_dir" function for this purpose, along with "is_file" and "is_link" to cover the most common format types...
There's an important (yet little-known) problem with file dates on Windows and Daylight Savings. This affects the 'atime' and 'mtime' elements returned by stat(), and it also affects other filesystem-related functions such as fileatime() and filemtime().
During the winter months (when Daylight Savings isn't in effect), Windows will report a certain timestamp for a given file. However, when summer comes and Daylight Savings starts, Windows will report a DIFFERENT timestamp! Even if the file hasn't been altered at all, Windows will shift every timestamp it reads forward one full hour during Daylight Savings.
This all stems from the fact that M$ 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) $file_date -= 3600;
?>
That will ensure that the timestamp you're working with is always consistently reported, regardless of whether the machine is in Daylight Savings or not.
If you want to know a directory size, this function will help you:
<?php
function dir_size($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';
?>
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.
The dir_size function provided by "marting.dc AT gmail.com" works great, except the $mas variable is not initialized. Add:
$mas = 0;
before the while() loop.
To ignore index number or name specifics.. use:
list($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size, $atime, $mtime, $ctime, $blksize, $blocks)
= lstat($directory_element);
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.
<?php
$stat = stat($filepath);
$mode = $stat[2];
?>
is identical to:
<?php $mode = fileperms($filepath); ?>
at least on my linux box.
This is a souped up 'stat' function based on
many user-submitted code snippets and
@ http://www.askapache.com/security/chmod-stat.html
Give it a filename, and it returns an array like stat.
<?php
function alt_stat($file) {
clearstatcache();
$ss=@stat($file);
if(!$ss) return false; //Couldnt stat file
$ts=array(
0140000=>'ssocket',
0120000=>'llink',
0100000=>'-file',
0060000=>'bblock',
0040000=>'ddir',
0020000=>'cchar',
0010000=>'pfifo'
);
$p=$ss['mode'];
$t=decoct($ss['mode'] & 0170000); // File Encoding Bit
$str =(array_key_exists(octdec($t),$ts))?$ts[octdec($t)]{0}:'u';
$str.=(($p&0x0100)?'r':'-').(($p&0x0080)?'w':'-');
$str.=(($p&0x0040)?(($p&0x0800)?'s':'x'):(($p&0x0800)?'S':'-'));
$str.=(($p&0x0020)?'r':'-').(($p&0x0010)?'w':'-');
$str.=(($p&0x0008)?(($p&0x0400)?'s':'x'):(($p&0x0400)?'S':'-'));
$str.=(($p&0x0004)?'r':'-').(($p&0x0002)?'w':'-');
$str.=(($p&0x0001)?(($p&0x0200)?'t':'x'):(($p&0x0200)?'T':'-'));
$s=array(
'perms'=>array(
'umask'=>sprintf("%04o",@umask()),
'human'=>$str,
'octal1'=>sprintf("%o", ($ss['mode'] & 000777)),
'octal2'=>sprintf("0%o", 0777 & $p),
'decimal'=>sprintf("%04o", $p),
'fileperms'=>@fileperms($file),
'mode1'=>$p,
'mode2'=>$ss['mode']),
'owner'=>array(
'fileowner'=>$ss['uid'],
'filegroup'=>$ss['gid'],
'owner'=>
(function_exists('posix_getpwuid'))?
@posix_getpwuid($ss['uid']):'',
'group'=>
(function_exists('posix_getgrgid'))?
@posix_getgrgid($ss['gid']):''
),
'file'=>array(
'filename'=>$file,
'realpath'=>(@realpath($file) != $file) ? @realpath($file) : '',
'dirname'=>@dirname($file),
'basename'=>@basename($file)
),
'filetype'=>array(
'type'=>substr($ts[octdec($t)],1),
'type_octal'=>sprintf("%07o", octdec($t)),
'is_file'=>@is_file($file),
'is_dir'=>@is_dir($file),
'is_link'=>@is_link($file),
'is_readable'=> @is_readable($file),
'is_writable'=> @is_writable($file)
),
'device'=>array(
'device'=>$ss['dev'], //Device
'device_number'=>$ss['rdev'], //Device number, if device.
'inode'=>$ss['ino'], //File serial number
'link_count'=>$ss['nlink'], //link count
'link_to'=>($s['type']=='link') ? @readlink($file) : ''
),
'size'=>array(
'size'=>$ss['size'], //Size of file, in bytes.
'blocks'=>$ss['blocks'], //Number 512-byte blocks allocated
'block_size'=> $ss['blksize'] //Optimal block size for I/O.
),
'time'=>array(
'mtime'=>$ss['mtime'], //Time of last modification
'atime'=>$ss['atime'], //Time of last access.
'ctime'=>$ss['ctime'], //Time of last status change
'accessed'=>@date('Y M D H:i:s',$ss['atime']),
'modified'=>@date('Y M D H:i:s',$ss['mtime']),
'created'=>@date('Y M D H:i:s',$ss['ctime'])
),
);
clearstatcache();
return $s;
}
?>
|=---------[ Example Output ]
Array(
[perms] => Array
(
[umask] => 0022
[human] => -rw-r--r--
[octal1] => 644
[octal2] => 0644
[decimal] => 100644
[fileperms] => 33188
[mode1] => 33188
[mode2] => 33188
)
[filetype] => Array
(
[type] => file
[type_octal] => 0100000
[is_file] => 1
[is_dir] =>
[is_link] =>
[is_readable] => 1
[is_writable] => 1
)
[owner] => Array
(
[fileowner] => 035483
[filegroup] => 23472
[owner_name] => askapache
[group_name] => grp22558
)
[file] => Array
(
[filename] => /home/askapache/askapache-stat/htdocs/ok/g.php
[realpath] =>
[dirname] => /home/askapache/askapache-stat/htdocs/ok
[basename] => g.php
)
[device] => Array
(
[device] => 25
[device_number] => 0
[inode] => 92455020
[link_count] => 1
[link_to] =>
)
[size] => Array
(
[size] => 2652
[blocks] => 8
[block_size] => 8192
)
[time] => Array
(
[mtime] => 1227685253
[atime] => 1227685138
[ctime] => 1227685253
[accessed] => 2008 Nov Tue 23:38:58
[modified] => 2008 Nov Tue 23:40:53
[created] => 2008 Nov Tue 23:40:53
)
)
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
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.
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.
A good explanation of the "mode" bits is given here:https://www.php.net/manual/en/function.fileperms.php