IO::Poll(3pm) Perl Programmers Reference Guide IO::Poll(3pm)

# [NAME](#NAME)

IO::Poll - Object interface to system poll call

# [SYNOPSIS](#SYNOPSIS)

```
    use IO::Poll qw(POLLRDNORM POLLWRNORM POLLIN POLLHUP);
    $poll = IO::Poll->new();
    $poll->mask($input_handle => POLLIN);
    $poll->mask($output_handle => POLLOUT);
    $poll->poll($timeout);
    $ev = $poll->events($input);
```

# [DESCRIPTION](#DESCRIPTION)

"IO::Poll" is a simple interface to the system level poll routine.

# [METHODS](#METHODS)

[mask ( IO \[, EVENT\_MASK \] )](#mask)

If EVENT\_MASK is given, then, if EVENT\_MASK is non-zero, IO is added to the list of file descriptors and the next call to poll will check for any event specified in EVENT\_MASK. If EVENT\_MASK is zero then IO will be removed from the list of file descriptors.

If EVENT\_MASK is not given then the return value will be the current event mask value for IO.

[poll ( \[ TIMEOUT \] )](#poll)

Call the system level poll routine. If TIMEOUT is not specified then the call will block. Returns the number of handles which had events happen, or -1 on error.

[events ( IO )](#events)

Returns the event mask which represents the events that happened on IO during the last call to "poll".

[remove ( IO )](#remove)

Remove IO from the list of file descriptors for the next poll.

[handles( \[ EVENT\_MASK \] )](#handles%28)

Returns a list of handles. If EVENT\_MASK is not given then a list of all handles known will be returned. If EVENT\_MASK is given then a list of handles will be returned which had one of the events specified by EVENT\_MASK happen during the last call to "poll".

# [SEE ALSO](#SEE_ALSO)

[**poll**(2)](/man/os/perl/poll.2), IO::Handle, IO::Select

# [AUTHOR](#AUTHOR)

Graham Barr. Currently maintained by the Perl Porters. Please report all bugs at <https://github.com/Perl/perl5/issues>.

# [COPYRIGHT](#COPYRIGHT)

Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2026-10-21 perl v5.44.0

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Document: IO::Poll(3pm) from perl 5.44.0-r2 (Chainguard OS)
Source: https://github.com/Perl/perl5.git