wordscan is a command line utility for searching dictionary word lists
(included) and thesaurus, with regular expression support.
It is using Runfile.
Option 1, with bundler:
$ bundle
Option 2, manually:
$ gem install runfile
$ run --help
$ run find animal ^d
Deer
Dog
Dolphin
Donkey
Dove
Duck
$ run find animal "^b.{1,3}$"
Bat
Bear
Bee
Bird
$ run find noun ^l --len 3
Lab
Law
Lid
Lie
$ run like network -l5
fret
grate
grid
lace
maze
mesh
net
sieve
weave
web
weft