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



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 v5.12.5                                     2012-10-11                                   FileCache(3pm)