require "x86asm.pl";
require "cbc.pl";
-$output = pop;
-open STDOUT,">$output";
+$output = pop and open STDOUT,">$output";
&asm_init($ARGV[0],$ARGV[$#ARGV] eq "386");
&cbc("BF_cbc_encrypt","BF_encrypt","BF_decrypt",1,4,5,3,-1,-1);
&asm_finish();
-close STDOUT;
+close STDOUT or die "error closing STDOUT: $!";
sub BF_encrypt
{