getlastmod

(PHP 4, PHP 5)

getlastmod — 最終更新時刻を取得する

説明

int getlastmod ( void )

現在のページの最終更新時刻を取得します。

別のファイルの最終更新時刻が知りたい場合は、 filemtime() を使用してください。

返り値

現在のページの最終更新時刻を返します。この値は Unix のタイムスタンプで、そのまま date ()に渡す事ができます。エラーの場合は FALSE を返します。

例

例1 getlastmod() の例


<?php
// たとえば、'最終更新時刻：March 04 1998 20:43:59.' を出力します
echo "最終更新時刻: " . date ("F d Y H:i:s.", getlastmod());
?>

参考

date() - ローカルの日付/時刻を書式化する
getmyuid() - PHP スクリプト所有者のユーザ ID を取得する
getmygid() - PHP スクリプトの所有者の GID を得る
get_current_user() - 現在の PHP スクリプトの所有者の名前を取得する
getmyinode() - 現在のスクリプトの inode を取得する
getmypid() - PHP のプロセス ID を取得する
filemtime() - ファイルの更新時刻を取得する

getmygid

getenv

[edit] Last updated: Fri, 10 Feb 2012

add a note User Contributed Notes getlastmod

erik dot stetina at gmail dot com 27-Sep-2011 03:47


function for displaying last modification time accross more direcotries. e.g. to display last modification date in "about" section of your web page



<?php

function array_prefix_values($prefix, $array)

{

  $callback = create_function('$s','return "'.$prefix.'".$s;');

  return array_map($callback,$array);

}



function get_last_update()

{

  if ( func_num_args() < 1 ) return 0;

  $dirs = func_get_args();

  $files = array();

  foreach ( $dirs as $dir )

  {

    $subfiles = scandir($dir);

    $subfiles = array_prefix_values($dir,$subfiles);

    $subfiles = array_filter($subfiles,"is_file");

    $files = array_merge($files,$subfiles);

  }

  $maxtimestamp = 0;

  $maxfilename = "";

  foreach ( $files as $file )

  {

    $timestamp = filemtime($file);

    if ( $timestamp > $maxtimestamp )

    {

      $maxtimestamp = $timestamp;

      $maxfilename = $file; 

    }

  }

  return date("Ymd",$maxtimestamp)." ($maxfilename)";

}



print "last update: ".get_last_update("./lib/", "./css/", "./lang/");

?>



OUTPUT:

last update: 20110927 (./lang/sk.php)

Ant P. 24-Feb-2010 10:48


If you use register_shutdown_function() on certain SAPIs, various filesystem-related things inside the shutdown function might do unexpected things, one of which being this function can return false.



On the other hand getlastmod() apparently caches the return value, so if you use it at least once in normal code it should work for the remainder of the request.

rwruck 17-Oct-2004 06:28


DO NOT use this function unless you are absolutely sure both your Apache and PHP have been compiled with the same value for -DFILE_OFFSET_BITS.



If not, this function will return the access time (or maybe even garbage) instead of the modification time due do Apache and PHP using different versions of the stat structure.



This is true regardless of Apache and PHP version.



To be on the safe side, always use the workaround already posted below:

filemtime($_SERVER['SCRIPT_FILENAME'])

19-May-2004 04:36


Setting the 'Last-Modified' header:

<?php

setlocale(LC_TIME, "C");

$ft = filemtime ('referencefile');

$localt = mktime ();

$gmtt = gmmktime ();

$ft = $ft - $gmtt + $localt;

$modified = strftime ("%a, %d %b %Y %T GMT", $ft);

?>

timeflys at users dot sourceforget dot net 20-Mar-2003 01:28


I found issues using getlastmod() to test whether or not I was successful in setting the Last Modified date in the header. The code below shows the same Last Modified date before and after I set the Last-Modified header.





<?php


//True modified date


$modified = date ("F d Y H:i:s.", getlastmod());


    


//artificial modified date - sent to header


$last_modified = gmdate('D, d M Y H:i:s T', (time() - 43200));


     


//caching prevention


header("Last-Modified: $last_modified GMT");


header("Cache-Control: no-store, no-cache, must-revalidate");  // HTTP/1.1


header("Cache-Control: post-check=0, pre-check=0", false);


    header("Pragma: no-cache");                          // HTTP/1.0





$getlast_modified = date ("F d Y H:i:s.", getlastmod());





print "True modified date(Before): $modified <p /> Date sent to header(After): $getlast_modified";


?>





I then used the PEAR, HTTP_Request class which worked, the Last-Modified date updates everytime it is requested, the desired effect.





<?php


require 'HTTP/Request.php';


$r = new HTTP_Request('http://www.sample.com/page.php');


$r->sendRequest();


$response_headers = $r->getResponseHeader();


print $response_headers["last-modified"];


?>

Richard Anderson(r85anderson at yahoo dot com) 17-Nov-2002 01:33


for includes....





<?php


//include.php


$file = __FILE__;


$lastmod = date("M d, Y @ h:ia", filemtime($file));


?>





<?php


//footer.php


echo("page last modified: $lastmod");


?>





[EDIT by danbrown AT php DOT net: Remember that $lastmod must not be a variable that is set or unset anywhere else in the script, or it will not work as expected when printed from the footer.]

kworthington ([no@spam)] linuxmaildotorg 03-Oct-2002 03:33


I was just informed of a workaround for the Apache 2.0 issue, do:

echo "Last modified: " . date("D F d Y h:i:s A", filemtime($_SERVER["SCRIPT_FILENAME"]));

Thanks to: Edward S. Marshall

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