zone "foo.com" {
type master
file path to the zone
};

zone "blah.com" {
type master 
file path to the zone 
};

zone "bar.com" {
type master 
file path to the zone 
};
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and running the script provided

qwurx [shmem] ~ > perl zonedel.pl 
please enter the domain name: foo.com
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I get as result

zone "blah.com" {
type master 
file path to the zone 
};

zone "bar.com" {
type master 
file path to the zone 
};
[download]

Yes, it starts with a blank line, but the zone definition is gone. What the heck did you run? Is it really that difficult to suppress blank lines? I'm running out of advice for you.

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}