qw(lpr -S SYSTEMX -P QGPL/SPYVIEW -o l $file)
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means

(split(' ', 'lpr -S SYSTEMX -P QGPL/SPYVIEW -o l $file'))
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Do you see the problem? If not, print out the contents of @cmd. Solution:

my @options = (
   -S => 'SYSTEMX',
   -P => 'QGPL/SPYVIEW',
   -o => 'l',
);

# Avoid being confused for an option.
$file =~ s{^(?=-)}{./};

system(lpr => @options, $file)
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