Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
FileCache(3)	       Perl Programmers	Reference Guide		  FileCache(3)

NAME
       FileCache - keep	more files open	than the system	permits

SYNOPSIS
	   no strict 'refs';

	   use FileCache;
	   # or
	   use FileCache maxopen => 16;

	   cacheout $mode, $path;
	   # or
	   cacheout $path;
	   print $path @data;

	   $fh = cacheout $mode, $path;
	   # or
	   $fh = cacheout $path;
	   print $fh @data;

DESCRIPTION
       The "cacheout" function will make sure that there's a filehandle	open
       for reading or writing available	as the pathname	you give it. It
       automatically closes and	re-opens files if you exceed your system's
       maximum number of file descriptors, or the suggested maximum maxopen.

       cacheout	EXPR
	   The 1-argument form of cacheout will	open a file for	writing	('>')
	   on it's first use, and appending ('>>') thereafter.

	   Returns EXPR	on success for convenience. You	may neglect the	return
	   value and manipulate	EXPR as	the filehandle directly	if you prefer.

       cacheout	MODE, EXPR
	   The 2-argument form of cacheout will	use the	supplied mode for the
	   initial and subsequent openings. Most valid modes for 3-argument
	   "open" are supported	namely;	'>', '+>', '<',	'<+', '>>',  '|-'  and
	   '-|'

	   To pass supplemental	arguments to a program opened with  '|-'  or
	   '-|'	append them to the command string as you would system EXPR.

	   Returns EXPR	on success for convenience. You	may neglect the	return
	   value and manipulate	EXPR as	the filehandle directly	if you prefer.

CAVEATS
       While it	is permissible to "close" a FileCache managed file, do not do
       so if you are calling "FileCache::cacheout" from	a package other	than
       which it	was imported, or with another module which overrides "close".
       If you must, use	"FileCache::cacheout_close".

       Although	FileCache can be used with piped opens ('-|' or	'|-') doing so
       is strongly discouraged.	 If FileCache finds it necessary to close and
       then reopen a pipe, the command at the far end of the pipe will be
       reexecuted - the	results	of performing IO on FileCache'd	pipes is
       unlikely	to be what you expect.	The ability to use FileCache on	pipes
       may be removed in a future release.

       FileCache does not store	the current file offset	if it finds it
       necessary to close a file.  When	the file is reopened, the offset will
       be as specified by the original "open" file mode.  This could be
       construed to be a bug.

       The module functionality	relies on symbolic references, so things will
       break under 'use	strict'	unless 'no strict "refs"' is also specified.

BUGS
       sys/param.h lies	with its "NOFILE" define on some systems, so you may
       have to set maxopen yourself.

perl v5.26.0			  2017-04-19			  FileCache(3)

NAME | SYNOPSIS | DESCRIPTION | CAVEATS | BUGS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=FileCache&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help