Given a poker hand, this sed script will output the name of the hand. For example, the hand Q:S 7:C Q:D 7:D 7:S (queen of spades, 7 of clubs, queen of diamonds, 7 of diamonds, 7 of spades) will output Full house. The hand can be in any order and the colons are optional.
The script comes in two flavors, compact and verbose. They contain identical logic, but have different goals. The compact version is an attempt to be as short as possible (796 characters); the verbose version is commented to explain how it works.
Here is the entire contents of compact.sed (manually wrapped at column 110):
#!/bin/sed -rf
x;s/.*//;x;s/10/T/g;tx;:x /([^2-9TJQKA]|[^ ].):/s/.*/Card has incorrect denomination/;tz;/:([^CDHS]|.[^ ])/s/.
*/Card has incorrect suit/;tz;s/[ :]//g;ty;:y /.{11}/s/.*/Too many cards/;tz;/.{10}/!s/.*/Too few cards/;tz;/(
.[CDHS]).*\1/s/.*/Duplicate card/;tz;s/^/23456789TJQKA /;ta;:a / $/bc;s/^(.)(.*) (.*)(\1.)(.*)$/\4 \1\2 \3\5/;
tb;s/^.//;ta;:b H;x;s/\n(..).*/\1/;x;s/^.. //;ta;:c g;/.(.)(.\1){4}/s/^/f/;s/[CDHS]//g;s/^/23456789TJQKA /;/(.
{5}).*\1/s/ / s/;s/.* //;te;:e /sf/{/A/s/.*/Royal flush/;t;s/.*/Straight flush/;b};/(.)\1{3}/s/.*/Four of a ki
nd/;t;/((.)\2(.)\3\3|(.)\4\4(.)\5)/s/.*/Full house/;t;/f/{s/.*/Flush/;b};/s/s/.*/Straight/;t;/(.)\1\1/s/.*/Thr
ee of a kind/;t;/(.)\1.*(.)\2/s/.*/Two pair/;t;/(.)\1/s/.*/One pair/;t;s/.*(.)/High card: \1/;s/T$/10/;b;:z s/
^/ERROR: /Example usage:
$ echo "5:H 5:D A:S 10:D 5:C" | src/compact.sed
Three of a kind
$ echo "2:H 3:H 4:H 5:H A:D" | src/compact.sed
High card: A
Invalid hands are also flagged:
$ echo "2:H 3:H 4:H 5:H A:D 5:C" | src/compact.sed
ERROR: Too many cards
$ echo "8:S 3:H 4:H 5:H 6:HS" | src/compact.sed
ERROR: Card has incorrect suit
A pair of input and output files are included to exercise the range output options (valid and invalid hands):
$ cat test/input.txt
10:H J:H Q:H K:H A:H
A:D K:D Q:D J:D 10:D
K:C J:C 10:C A:C Q:C
Q:S K:S A:S 10:S J:S
2:H 3:H 4:H 5:H 6:H
K:D Q:D J:D 10:D 9:D
2:S 2:H 2:D 4:C 2:C
J:S J:C 5:H J:H J:D
Q:S 7:C Q:D 7:D 7:S
7:S Q:C 7:D Q:D Q:S
A:D 6:D 7:D 9:D 2:D
2:D 3:H 4:H 5:H 6:C
5:C 6:H 7:D 8:D 9:D
5:H 5:D A:S 10:D 5:C
8:H J:S 8:S 3:D 3:H
A:D 2:D 2:C 9:S A:H
Q:S 2:H 3:H 4:H Q:H
2:H 3:H 4:H 5:H 7:D
2:H 3:H 4:H 5:H 10:D
2:H 3:H 4:H 5:H J:D
2:H 3:H 4:H 5:H Q:D
2:H 3:H 4:H 5:H K:D
2:H 3:H 4:H 5:H A:D
2:H 3:H 4:H 5:H A:D 5:C
2:H 3:H 4:H 5:H
2:H 3:H 4:H 2:H J:H
2:U 3:H 4:H 5:H 6:H
12:U 3:H 4:H 5:H 6:H
2:S 3:H 14:H 5:H 6:H
8:S 3:H 4:HS 5:H 6:H
8:S 3:H 4:H 5:H 6:HS
8:S 8:S 8:H 8:D 8:C
$ src/compact.sed test/input.txt
Royal flush
Royal flush
Royal flush
Royal flush
Straight flush
Straight flush
Four of a kind
Four of a kind
Full house
Full house
Flush
Straight
Straight
Three of a kind
Two pair
Two pair
One pair
High card: 7
High card: 10
High card: J
High card: Q
High card: K
High card: A
ERROR: Too many cards
ERROR: Too few cards
ERROR: Duplicate card
ERROR: Card has incorrect suit
ERROR: Card has incorrect denomination
ERROR: Card has incorrect denomination
ERROR: Card has incorrect suit
ERROR: Card has incorrect suit
ERROR: Duplicate card
This is also the contents of "test/output.txt". The included makefile can be run to verify that the scripts (compact and verbose) are working correctly:
$ make
[SUCCESS] src/compact.sed
[SUCCESS] src/verbose.sed
Note for OS X users: The version of sed installed has different options than the Linux one. Notably, it does not have the extended-regex option '-r'. I recommend building the latest version from here: http://sed.sourceforge.net/