Program printing all possible combinations of TCP flags

[Rainer Weikusat]

Main function of this program is/was to generate a list of C string
literals used to populate an array which can be used to map the
numerical value of the flags field in a TCP header to a string
containing an uppercase letter (Fin, Syn, Rst, Psh, Ack, Urg) for each
set flag. Since it is kind-of cute an the algorithm is (IMHO) not
completely trivial/ obvious anymore, I thought I'd just post it here:

NB: This is fairly fast at the expense of possibly consuming huge
amounts of memory.

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#!/usr/bin/perl

my @flags = qw(F S R P A U);

{
my @all;

push(@all, '');

for my $f (@flags) {
push(@all, map { $_.$f; } @all);
}

printf("\"%s\",\n", $_) for (@all);
}
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