gg48gg has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to handle a ctrl-c signal ( $SIG{'INT'} ), but my program is not capturing it. I am pretty sure this is due to the program currently waiting on input from STDIN via IO::Prompt. When I hit ctrl-c, the program stops and my handling doesn't happen. The handler does work if I insert a sleep and interrupt the sleep.

My question, is how can I capture the signal while using IO::Prompt, or do I have to prompt without using that module? 
#!/bin/perl -w
use strict;
use IO::Prompt;
$SIG{'INT'} = 'INT_handler';

my $PROMPT="Yes or no? [YES,no] :";
while (prompt $PROMPT, -until => qr/YES|n|N/) {
    print "\nExcuse me? Say again?\n\n";
}
my $YES_NO=$_;



sub INT_handler {
 print_info("Caught signal Interupt.  Cleaning up...");
 exit(0);
}

[download]

Replies are listed 'Best First'.
Re: Not Catching Signals While Program is Prompting with IO::Prompt
by BrowserUk (Patriarch) on Jun 08, 2012 at 21:02 UTC

    Probably because like some many overspecified CPAN modules, IO::Prompt throws everything including the kitchen sink at solving what are essentially simple problems, without considering the knock-on affects upon the callers code.

    In this case, the kitchen sink is Term::Readkey and ReadMode 'raw', $IN;.

    It compounds that by taking the unilateral decision to terminate the calling process if the user type ^C:

        local $SIG{INT} = sub { ReadMode 'restore', $IN; exit };

    [download]
    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.

    The start of some sanity?
[reply]
[d/l]
[select]
      That sucks. Thanks for the response. I didn't like it that much anyway. I think I will write my own sub to prompt.
[reply]
      found this bug... https://rt.cpan.org/Ticket/Display.html?id=38014
[reply]

        2008. It doesn't look like anythings going to change any time soon.

        Frankly, the module is overkill for what it does. A simple loop that prompts and re-prompts until the input matches a regex is pretty trivial to write. 

        sub promptTill{{ 
    local $\;
    print "$_[0]: "; 
    chomp( my $input = <STDIN> ); 
    redo unless $input =~ $_[1]; 
    return $input 
}}

print promptTill( 'Yes/No', qr[^(?:y(?:e(?:s)?)?|n(?:o)?)$]i );;

        [download]
        With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.

        The start of some sanity?
[reply]
[d/l]

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