clearstatcache(3) [php man page]

CLEARSTATCACHE(3)							 1							 CLEARSTATCACHE(3)

clearstatcache - Clears file status cache

SYNOPSIS

       void clearstatcache ([bool  $clear_realpath_cache = false], [string  $filename])

DESCRIPTION

	When  you  use	stat(3), lstat(3), or any of the other functions listed in the affected functions list (below), PHP caches the information
       those functions return in order to provide faster performance. However, in certain cases, you may want to clear the cached information. For
       instance,  if  the same file is being checked multiple times within a single script, and that file is in danger of being removed or changed
       during that script's operation, you may elect to clear the status cache. In these cases, you can  use  the  clearstatcache(3)  function	to
       clear the information that PHP caches about a file.

	You  should  also  note that PHP doesn't cache information about non-existent files. So, if you call file_exists(3) on a file that doesn't
       exist, it will return FALSE until you create the file. If you create the file, it will return TRUE even if you then delete the  file.  How-
       ever unlink(3) clears the cache automatically.

       Note

	       This  function caches information about specific filenames, so you only need to call clearstatcache(3) if you are performing multi-
	      ple operations on the same filename and require the information about that particular file to not be cached.

	Affected functions include stat(3), lstat(3), file_exists(3), is_writable(3),  is_readable(3),	is_executable(3),  is_file(3),	is_dir(3),
       is_link(3), filectime(3), fileatime(3), filemtime(3), fileinode(3), filegroup(3), fileowner(3), filesize(3), filetype(3), and fileperms(3).

PARAMETERS

	      o $clear_realpath_cache
		- Whether to clear the realpath cache or not.

	      o $filename
		- Clear the realpath and the stat cache for a specific filename only; only used if $clear_realpath_cache is TRUE.

RETURN VALUES

	No value is returned.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.0	|						    |
       |	|						    |
       |	|  Added  optional $clear_realpath_cache and $file- |
       |	| name parameters.				    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      clearstatcache(3) example

	      <?php
	      $file = 'output_log.txt';

	      function get_owner($file)
	      {
		  $stat = stat($file);
		  $user = posix_getpwuid($stat['uid']);
		  return $user['name'];
	      }

	      $format = "UID @ %s: %s
";

	      printf($format, date('r'), get_owner($file));

	      chown($file, 'ross');
	      printf($format, date('r'), get_owner($file));

	      clearstatcache();
	      printf($format, date('r'), get_owner($file));
	      ?>

	      The above example will output something similar to:

	      UID @ Sun, 12 Oct 2008 20:48:28 +0100: root
	      UID @ Sun, 12 Oct 2008 20:48:28 +0100: root
	      UID @ Sun, 12 Oct 2008 20:48:28 +0100: ross

PHP Documentation Group 													 CLEARSTATCACHE(3)

Historical(3pm) 					User Contributed Perl Documentation					   Historical(3pm)

NAME

       Cache::Historical - Cache historical values

SYNOPSIS

	   use Cache::Historical;

	   my $cache = Cache::Historical->new();

	      # Set a key's value on a specific date
	   $cache->set( $dt, $key, $value );

	      # Get a key's value on a specific date
	   my $value = $cache->get( $dt, $key );

	      # Same as 'get', but if we don't have a value at $dt, but we
	      # do have values for dates < $dt, return the previous
	      # historic value.
	   $cache->get_interpolated( $dt, $key );

DESCRIPTION

       Cache::Historical caches historical values by key and date. If you have something like historical stock quotes, for example

	   2008-01-02 msft 35.22
	   2008-01-03 msft 35.37
	   2008-01-04 msft 34.38
	   2008-01-07 msft 34.61

       then you can store them in Cache::Historical like

	   my $cache = Cache::Historical->new();

	   my $fmt = DateTime::Format::Strptime->new(
			 pattern => "%Y-%m-%d");

	   $cache->set( $fmt->parse_datetime("2008-01-02"), "msft", 35.22 );
	   $cache->set( $fmt->parse_datetime("2008-01-03"), "msft", 35.37 );
	   $cache->set( $fmt->parse_datetime("2008-01-04"), "msft", 34.38 );
	   $cache->set( $fmt->parse_datetime("2008-01-07"), "msft", 34.61 );

       and retrieve them later by date:

	   my $dt = $fmt->parse_datetime("2008-01-03");

	     # Returns 35.37
	   my $value = $cache->get( $dt, "msft" );

       Even if there's no value available for a given date, but there are historical values that predate the requested date, "get_interpolated()"
       will return the next best historical value:

	   my $dt = $fmt->parse_datetime("2008-01-06");

	     # Returns undef, no value available for 2008-01-06
	   my $value = $cache->get( $dt, "msft" );

	     # Returns 34.48, the value for 2008-01-04, instead.
	   $value = $cache->get_interpolated( $dt, "msft" );

   Methods
       new()
	   Creates the object. Takes the SQLite file to put the date into as an additional parameter:

	       my $cache = Cache::Historical->new(
		   sqlite_file => "/tmp/mydata.dat",
	       );

	   The SQLite file defaults to

	       $HOME/.cache-historical/cache-historical.dat

	   so if you have multiple caches, you need to use different SQLite files.

       time_range()
		  # List the time range for which we have values for $key
	       my($from, $to) = $cache->time_range( $key );

       keys()
		  # List all keys
	       my @keys = $cache->keys();

       values()
		  # List all the values we have for $key, sorted by date
		  # ([$dt, $value], [$dt, $value], ...)
	       my @results = $cache->values( $key );

       clear()
		  # Remove all values for a specific key
	       $cache->clear( $key );

		  # Clear the entire cache
	       $cache->clear();

       last_update()
		  # Return a DateTime object of the last update of a given key
	       my $when = $cache->last_update( $key );

       since_last_update()
		  # Return a DateTime::Duration object since the time of the last
		  # update of a given key.
	       my $since = $cache->since_last_update( $key );

LEGALESE

       Copyright 2007-2011 by Mike Schilli, all rights reserved.  This program is free software, you can redistribute it and/or modify it under
       the same terms as Perl itself.

AUTHOR

       2007, Mike Schilli <cpan@perlmeister.com>

perl v5.10.1							    2011-04-27							   Historical(3pm)