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



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 v5.20.2                                2014-12-27                           FileCache(3perl)