


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


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



perl v5.10.1                2009-10-12                          1





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


       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 v5.10.1                2009-10-12                          2


