Re^3: how to use angle operator with timeout?

[Anonymous Monk]

in reply to Re^2: how to use angle operator with timeout?
in thread how to use angle operator with timeout?

http://perldoc.perl.org/perlport.html#alarm

Emulated using timers that must be explicitly polled whenever Perl wants to dispatch "safe signals" and therefore cannot interrupt blocking system calls. (Win32)

[BrowserUk]

I know that they do not work on win32, and why.

My question was: can signals -- alarm generated or otherwise -- interrupt blocking IO on *nix in under the auspices of safe-signals?

[Anonymous Monk]

perlipc Deferred Signals (Safe Signals) Interrupting IO says it could happen, but it probably won't, you should use unsafe signals via POSIX::SigAction or Perl::Unsafe::Signals

[BrowserUk]

you should use

That'll be tobyink and/or the OP that need to do that. Or maybe not? (Damn! It is hard to get a straight answer around here :()

[tmharish]

This works on *nix:

use strict   ;
use warnings ;

my $timeout_in = 5 ;

eval {
    local $SIG{ALRM} = sub { die "timed_out\n" };
    alarm($timeout_in);
    while(<>) { 
    alarm($timeout_in);
    my $in = $_ ;
    chomp( $in ) ;
    print $in . "\n" ;
    last if( $in eq 'exit' );
    }
    alarm(0) ;
};
if ($@) {
    die( "Hey ... whats with the slow typing ??\n" );
}

[BrowserUk]

Really? Actual tested code on which flavour of *nix & Perl please?

Because that seems to contradict anonymonk's reading of the docs?