getlastmod

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

getlastmodGets time of last page modification

Description

getlastmod(): int|false

Gets the time of the last modification of the main script of execution.

If you're interested in getting the last modification time of a different file, consider using filemtime().

Parameters

This function has no parameters.

Return Values

Returns the time of the last modification of the current page. The value returned is a Unix timestamp, suitable for feeding to date(). Returns false on error.

Examples

Example #1 getlastmod() example

<?php
// outputs e.g. 'Last modified: March 04 1998 20:43:59.'
echo "Last modified: " . date ("F d Y H:i:s.", getlastmod());
?>

See Also

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User Contributed Notes 7 notes

up
5
luca dot delpivo at gmail dot com
12 years ago
With better words getlastmod() returning the last time the script in which it is being called was modified, it does not require or use a parameter.
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4
Moro
11 years ago
Return latest mod time of all included files:

<?php
function get_page_mod_time() {
   
$incls = get_included_files();
   
$incls = array_filter($incls, "is_file");
   
$mod_times = array_map('filemtime', $incls);
   
$mod_time = max($mod_times);

    return
$mod_time;
}
?>
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-1
Ant P.
14 years ago
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.
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-2
rwruck
19 years ago
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'])
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-3
Anonymous
19 years ago
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);
?>
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-8
timeflys at users dot sourceforget dot net
20 years ago
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"];
?>
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-8
erik dot stetina at gmail dot com
12 years ago
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)
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