Unfortunatly this could produce zombies. How could I prevent this?

A fairly standard perl "reaper" construct is: 

use POSIX qw/WNOHANG/;

## ...

$SIG{ CHLD } = sub {
        while ( waitpid( -1, WNOHANG ) > 0 )
        { ## what to do, empty here }
    };

## fork down here

[download]

Look up wait() and waitpid(), those are the functions to help you with terminating children.

The following is a little touched up verbose version you can build from.

#!/usr/bin/perl -w

use strict;
use POSIX qw/WNOHANG/;

my $time    = 5;

$SIG{ CHLD } = sub {
        while ( ( my $x = waitpid( -1, WNOHANG ) ) > 0 )
        { print "\tprocess '$x' got reaped.\n" }
    };

my @toDoList = (
    'ls -la',    'echo Yay!',
    'date',        'perl -V',
);

foreach my $doIt ( @toDoList ) {

    my $child = fork();
    defined $child or die "Can not fork: $!";

    if ( $child > 0 ) {    ## parent

        print "Parent of $child sleeping for $time seconds . . .\n";
        sleep( $time );
        print "Parent of $child done sleeping!\n";

    } else {        ## child

        print "Child, going to do '$doIt'\n";
        exec( "$doIt && echo '** Finished \"$doIt\" **'" );

    }

}

print "\nDone.\n\n";
exit(0);

[download]

I added && echo '** Finished \"$doIt\" **' to the exec call just to be even more verbose, it is not needed, nor wanted, in your actual code

Will perl for money
JJ Knitis
(901) 756-7693
gt8073a@industrialmusic.com

In reply to Re: zombies after forking by gt8073a
in thread zombies after forking by very empty

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