Keyboard Input Interrupt

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi there,

I've got a question concerning interruption of user input with CTRL-C. What I'm trying to do is this:

# Main part
while (1)
{
    &get_input
}

sub get_input
{
    # Give prompt
    $reply = <STDIN>;

    if ( .."CTRL-C pressed".. ) { return 0; }
    else
    {
        # continue...
    }
}
[download]

But if I use $SIG{'INT'} I can only assign a subroutine as handler, not a command like 'return' or 'last'. Now the only way it works is if the user presses CTRL-C, finishes his/her input and presses enter. What I would like to see is that the input is interrupted and the get_input subroutine 'aborts' or returns.

Is there a way to do this with normal <STDIN> input without having to use Term::ReadLine or some equivalent (which I'm not familiar with)?

Comment on Keyboard Input Interrupt Download Code

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Re: Keyboard Input Interrupt by t0mas (Priest) on Dec 05, 2000 at 18:15 UTC
This works for me: `#!/usr/bin/perl -w use strict; use vars qw($ret $reply); # Signal handler $SIG{INT} = 'intSub'; while (1) { $ret=get_input(); print "\nget_input returned: $ret\n"; } sub get_input { # Give prompt print "Enter value: "; $reply=<STDIN>; return 0 unless $reply; chomp($reply); print "You typed: $reply\n"; return 1; } sub intSub { # Reset signal handler $SIG{INT} = 'intSub'; };` [download] I've only used this code on win2k, so I can't say that it will work on *nix boxes. You'll have to try that for yourself. /brother t0mas	[reply] [d/l]

Replies are listed 'Best First'.

Re: Keyboard Input Interrupt
by t0mas (Priest) on Dec 05, 2000 at 18:15 UTC

#!/usr/bin/perl -w

use strict;
use vars qw($ret $reply);

# Signal handler
$SIG{INT} = 'intSub';

while (1) {
    $ret=get_input();
    print "\nget_input returned: $ret\n"; 
}

sub get_input {
    # Give prompt
    print "Enter value: ";
    $reply=<STDIN>;

    return 0 unless $reply;

    chomp($reply);
    print "You typed: $reply\n";

    return 1;
}

sub intSub {
    # Reset signal handler
    $SIG{INT} = 'intSub';
};
[download]

[reply]
[d/l]