You have already gotten the answers you need, but let me point out one more issue that might cause trouble. You code says:

$system1 = <STDIN>;   # this is manual input from the keyboard
#...
$system1 =~ s/\W.*//;  # what if input was " box1" (initial space)?
#...
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You could simplify this as follows:

( $system1 = <STDIN> ) =~ s/^\W*(\w+).*/$1/s;
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(By including the "s" modifier on the substitution, you don't need to do "chomp", because the ".*" will match the final new-line.)

But personally, I always prefer to get this sort of user input from the command line, via @ARGV. Programs that start up, then pause, print a prompt and wait until something gets typed at the keyboard are such a pain.

my %systems = ( box1 => 1, box2 => 2 );

my $Usage = "Usage:  $0  (" . join('|', sort keys %systems) . ")\n";

die $Usage unless ( @ARGV == 1 and $systems{$ARGV[0]} );

$system1 = lc( shift );
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