FileCache

FileCache(3)	       Perl Programmers Reference Guide		 FileCache(3)



NAME
       FileCache - keep more files open than the system permits

SYNOPSIS
	   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 auto-
       matically closes and re-opens files if you exceed your system’s maxi-
       mum 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 neces-
       sary to close a file.  When the file is reopened, the offset will be
       as specified by the original "open" file mode.  This could be con-
       strued to be a bug.

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



perl v5.8.8			  2001-09-21			 FileCache(3)