FileCache(3pm) Perl Programmers Reference Guide FileCache(3pm)
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 avail-able available
able as the pathname you give it. It automatically closes and re-opens files if you exceed your sys-tem's system's
tem'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 append-ing appending
ing ('>>') 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 open-ings. openings.
ings. 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 com-mand command
mand 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 "File-Cache::cacheout" "FileCache::cacheout"
Cache::cacheout" from a package other than which it was imported, or with another module which over-rides overrides
rides "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.
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(3pm)
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