dldist is a command line utility that returns the Damerau-Levenshtein distance
The distance from 'citten' to 'kitten':
$ dldist -from citten -to kitten
1: [citten] 'kitten'
The program also accepts a dictionary file.
$ dldist -dictionary ~/Documents/en.txt -from citten
1: [citten] 'bitten' 'cittern' 'kitten' 'litten' 'mitten' 'pitten' 'sitten' 'yitten'
To check multiple words at once we can use the -list parameter..
$ dldist -dictionary ~/Documents/en.txt -list ~/Documents/file.txt
0: [mug] 'mug'
...