First, what are the errors you see? I know of at least two ones ...

Why don't you just write this in sed or awk or some other shell scripting language? I mean, that's basically what your Perl script is ...

If you wanted to write this in Perl, I'd do something like the following:

use strict;
use warnings;

my $app = 'nscd';
print "Looking for '$app'\n";
while (1)
{
    open PS, "ps -ef |"
        || die "Cannot open ps command: $!\n";
    my @cmd =
        grep { /$app/ }
            <PS>;
    close PS;

    last unless @cmd;

    print "'$app' is still running ...\n";
    sleep 2;
}

print "'$app' is finished.\n";
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