How to end "do" with Ctrl-C

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

Hello, I need to end the "do" statement with user intervention. My idea is to do this with "until" after the }} but I am unsure of how to get the until in there and accept CRTL-C as the exit. If there is a better way, let me know. Thank you in advance for your assistance.

use strict;

my $line;

chomp($line = <stdin>);


if ($line eq "\n") {
    print "There was no port number!\n";
} else {
    do{{
        $line;   
        system ("netstat -an | grep $line \n");
                system ("sleep 10");
        redo;
        }}
    }
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Comment on How to end "do" with Ctrl-C Download Code

Replies are listed 'Best First'.

Re: How to end "do" with Ctrl-C
by pfaut (Priest) on Dec 02, 2008 at 22:33 UTC

You need to trap the INT signal.

our $stopit = 0;
$SIG{INT} = sub  { $stopit++; };

while (!$stopit) {
    system("netstat -an | grep $line");
    sleep 10;
}
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90% of every Perl application is already written. ⇒

dragonchild

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[d/l]

Re^2: How to end "do" with Ctrl-C

by kennethk (Abbot) on Dec 02, 2008 at 23:03 UTC

pfaut

use strict; 
my $port = shift; 

our $stopit = 0; 
$SIG{INT} = sub { $stopit++; }; 

if (!$port or $port =~ /\D/) { 
    print "usage: program port_num\n"; 
} else { 
    while (!$stopit) { 
        print system("netstat -an | grep $port"), "\n"; 
        sleep 10; 
    } 
}
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or whatever variant will get you what you want.

[reply]
[d/l]

Re^3: How to end "do" with Ctrl-C

by ikegami (Patriarch) on Dec 03, 2008 at 00:12 UTC

print system("netstat -an | grep $port"), "\n";

That should be

system("netstat -an | grep $port");
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print qx{netstat -an | grep $port};
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print grep /$port/, qx{netstat -an};
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