#!/usr/local/bin/perl -w
use strict;

# a bit string
my $bits = '';

# set some of the bits
my @offsets = (0, 2, 4, 6);
for my $offset (@offsets) {
    vec($bits, $offset, 1)  = 1;
}

# test which bits are set
my @bits = (0 .. 10);
for my $bit (@bits) {
    if (vec($bits, $bit, 1)) {
        print "bit $bit is set\n";
    } else {
        print "bit $bit is not set\n";
    }
}
__END__
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$ ./vec-demo.pl 
bit 0 is set
bit 1 is not set
bit 2 is set
bit 3 is not set
bit 4 is set
bit 5 is not set
bit 6 is set
bit 7 is not set
bit 8 is not set
bit 9 is not set
bit 10 is not set
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