June 2002
Beginner
759 pages
80h 42m
English
select
select rbits, wbits, ebits, timeout
The four-argument select
operator is totally unrelated to the previously described select operator. This operator is for
discovering which (if any) of your file descriptors are ready to
do input or output, or to report an exceptional condition. It
calls the select(2) system call
with the bitmasks you’ve specified, which you can construct using
fileno and vec, like this:
$rbits = $wbits = $ebits = ""; vec($rbits, fileno(STDIN), 1) = 1; vec($wbits, fileno(STDOUT), 1) = 1; $ein = $rin | $win;
The select call blocks
until one or more file descriptors is ready for reading, writing,
or reporting an error condition.
timeout is given in seconds and tells
select how long to wait.