CGIに依存しないPerlの話題一般/Part2

ぎゃふん。
なるほどfileno()ですか。

% perldoc -f open

If you specify "'<&=N'", where "N" is a number, then Perl will
do an equivalent of C's "fdopen" of that file descriptor; this
is more parsimonious of file descriptors. For example:

open(FILEHANDLE, "<&=$fd")

でも
Note that this feature depends on the fdopen() C library
function. On many UNIX systems, fdopen() is known to fail when
file descriptors exceed a certain value, typically 255. If you
need more file descriptors than that, consider rebuilding Perl
to use the "sfio" library.

ってビミョーですな。