First you input $groupDir from STDIN, then you replace it with that was previously supplied on the command line. That doesn't make any sense. Do you want to the caller to provide it via STDIN or via command line? (I'd pick the latter.)

the script will run with those switches.

Presumably this this the line that launches the script.

$ENV{`CLD_RV/rv_char.tcl -cell $cell`);
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Aside that it's mostly nonsense, You seem to forgot to pass the switches.

Global symbol "$opt_d" requires explicit package name

uh, that error doesn't come from the code you posted.