It's not obvious from the code you posted. However, I will guess that if you used my instead of local on your variables as appropriate, you'd clear up the error. Try this line instead:

my $status = system("mv $filename1 $newfile");

Of course, I'd write that code as:

unless (system("mv $filename1 $newfile") == 0)
{
    print "FAILED WHILE MOVING mv $filename1$newfile\n";
    return 1;
}
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That avoids the variable altogether.

Another suggestion is to look into the module File::Copy and the operators unlink and rename, so as to avoid unnecessary system calls.