IO::Select

Native implementation of IO::Select

Provides multiplexed I/O via the POSIX select() system call, compatible with Perl’s IO::Select module.

IO::Select objects are blessed hashrefs internally storing:

• __fds: an Av mapping fd_number -> stored handle (the original Sv)

• __count: integer count of registered handles

Functions

new

Constructor. Creates an IO::Select object, optionally pre-populated with an initial set of handles.

use IO::Select;
my $sel = IO::Select->new();
my $sel = IO::Select->new($fh1, $fh2);

add

Adds one or more handles to the select set. Returns the number of handles added.

$sel->add($fh);
$sel->add(\*STDIN, $sock);

remove

Removes one or more handles from the select set. Returns the number of handles removed.

$sel->remove($fh);

count

Returns the number of handles currently registered.

my $n = $sel->count();

handles

Returns a list of all registered handles.

my @fhs = $sel->handles();

exists

Checks if a given handle is in the select set. Returns the stored handle if present, undef otherwise.

if (defined $sel->exists($fh)) { ... }

bits

Returns the vec-style bitmask string suitable for the 4-argument select() builtin. Returns undef if the set is empty.

my $bits = $sel->bits();

can_read

Returns a list of handles that are ready for reading within the given timeout (seconds, fractional allowed).

my @ready = $sel->can_read(0.5);

can_write

Returns a list of handles that are ready for writing within the given timeout.

my @ready = $sel->can_write(1.0);

has_exception

Returns a list of handles that have pending exceptions within the given timeout.

my @exc = $sel->has_exception(0);

select

Static/class method. Performs a POSIX select(2) across up to three IO::Select objects (readers, writers, errors) with a timeout. Returns three arrayrefs of ready handles, or an empty list on timeout.

my ($r, $w, $e) = IO::Select->select($readers, $writers, $errors, $timeout);