Given count.pl that looks like this:

C:\test>type count.pl
#! perl -slw
use strict;
use 5.010;

say for 1 .. 1e6;
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You can run that script using this script:

#! perl -slw
use strict;
use Win32::Process;

Win32::Process::Create(
    my $hProc,
    '/perl64/bin/perl.exe',
    'perl count.pl',
    0,
    0,
    '.'
) or die $^E;

my $state = 1;
while( <STDIN> ) {
    if( $state ) {
        $hProc->Suspend();
        $state = 0;
    }
    else {
        $hProc->Resume();
        $state = 1;
    }
    print "\nProcess is ", $state ? 'running' : 'suspended';
}
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And each time you press enter on the command line, count.pl will be suspended or resumed.

But again it keeps on waiting for some input from user as the process does not finish. It cmd running the process keeps on waiting. Why?