Simple front end to grep and the dictionary word list to help in solving word based puzzles, for example, if you stuck on those in "The GCHQ Puzzle Book"

word.sh

#!/bin/bash
# Various utilities to help with the GCHQ Puzzle Book...

wordlist="/usr/share/dict/british-english"
formatter="column"

# turn off filename globbing (we never need it)
set -f

if [[ $# -lt 2 ]]; then
	cat<<ENDHELP
Usage: word [flags] command string...

Commands are:
starts - show all words starting with string
ends - show all words ending with string
contains - show all words that have string embedded
anagram - show all (partial) anagrams of string
surround - show all words that start with string1 and end with string2 (*)
prefix - show the remaining part of all words starting with string (*)
suffix - show the remaining part of all words ending with string (*)
search - treat string as an abitrary regular expression
(all commands may be abbreviated to their shortest unique length)

Flags are:
-w - ensure that output of the commands marked (*) are actually words
-1 - output results in a single column (for piping to other commands)
-p - don't include proper nouns in the results
-s - don't include possessives in the results

ENDHELP
	exit 1
fi

while true; do
	case "$1" in
	-w) realWords=true; shift;;
	-1) onePerLine=true; shift;;
	-p) noProperNouns=true; shift;;
	-s) noPossessives=true; shift;;
	*) break;
	esac
done

# This is where the work gets done...
case "$1" in
st*) result=$(grep "^$2" $wordlist);;
e*) result=$(grep "${2}\$" $wordlist);;
a*) len=${#2}; result=$(grep -E "^[$2]{$len}\$" $wordlist);;
c*) result=$(grep "..*$2.*." $wordlist);;
se*) result=$(grep -E "$2" $wordlist);;
sur*) result=$(grep "^$2..*${3}\$" $wordlist | sed -e "s/^$2//" -e "s/$3$//");;
suf*) result=$(grep "${2}\$" $wordlist | sed -e "s/${2}\$//");;
p*) result=$(grep "^$2" $wordlist | sed -e "s/^$2//");;
*) echo "Unknown command"; exit 2;;
esac

# And here is where the output is filtered and formatted
if [[ ! -z $noProperNouns ]]; then
	filteredResult=""
	for item in $result; do
		if [[ ${item:0:1} =~ [a-z] ]] ; then
			filteredResult="$filteredResult $item"
		fi
	done
	result=$filteredResult
fi

if [[ ! -z $realWords ]]; then
	filteredResult=""
	for item in $result; do
		if grep -q "^${item}\$" $wordlist ; then
			filteredResult="$filteredResult $item"
		fi
	done
	result=$filteredResult
fi

if [[ ! -z $noPossessives ]]; then
	filteredResult=""
	re="'s"
	for item in $result; do
		if [[ ! $item =~ $re ]] ; then
			filteredResult="$filteredResult $item"
		fi
	done
	result=$filteredResult
fi

if [ -z $onePerLine ]; then
	echo $result | sed -e "s/ /\n/g" | $formatter
else
	for item in $result; do
		echo $item
	done
fi

exit 0