FileCache(3p) Perl Programmers Reference Guide FileCache(3p)
FileCache - keep more files open than the system permits
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;
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.
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
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FileCache(3p) Perl Programmers Reference Guide FileCache(3p)
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.
sys/param.h lies with its "NOFILE" define on some systems,
so you may have to set maxopen yourself.
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