and depending what has been written there, alter a variable:

...
if ($ARGV[1] eq '-SMC') {$cust eq "SMC";}
...
[download]

You don't alter, you are comparing, twice. It's the second comparison ($cust eq "SMC") which leads to the warning. You mean:

if ($ARGV[1] eq '-SMC') {$cust = "SMC";}
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But I guess for what you want, this is enough:

#!/usr/local/bin/perl -w
use strict;
my($target, $cust, $cotime) = @ARGV;

$cust =~ s/^-//; # strip leading dash
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_($_=" "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}