Can I use POSIX signals in my Perl program to create event-driven programming?

If you want to do event-driven programming, take a look at one of the CPAN event modules, such as POE, Coro, or AnyEvent before you invent your own thing.

Update for 2020

I'm doing this with Mojo::EventEmitter, which I cover very briefly in my book Mojo Web Clients.

You can use select to monitor communications channels (note: if you are on Win32 select can only be used on a socket).

So you can use code like this:

use IO::Select;use IO::Handle;...$_->blocking(0) for @handles;while( 1 ) {    my $s = IO::Select->new( @handles );    for my $h ( $s->can_read( 1 ) ) {        my $data = read_handle($h);        process_handle_data( $data );    }}sub read_handle {    my $h = shift;    my $got = '';    1 while read( $h, $got, 1024, length $got );    return $got;}

Take a look at the UDP example in perlipc. It uses the select built-in. I prefer the core IO::Select module to the select built-in, it's much easier to read.

Update: You really should consider using an event framework like POE, Event or Coro. There's a pretty good list of options in this perlmonks thread. Don't fear CPAN.

To answer the direct question, SIGUSR1 and SIGUSR2 are intended for 'user-defined' purposes - so you could use them.

You might be better off looking at a pre-existing system, though.