Q: I need a sort of an ``approximate'' strcmp routine, for comparing two strings for close, but not necessarily exact, equality.
A: Some nice information and algorithms having to do with approximate string matching, as well as a useful bibliography, can be found in Sun Wu and Udi Manber's paper ``AGREP--A Fast Approximate Pattern-Matching Tool.''
Another approach involves the ``soundex'' algorithm, which maps similar-sounding words to the same codes. Soundex was designed for discovering similar-sounding names (for telephone directory assistance, as it happens), but it can be pressed into service for processing arbitrary words.
Knuth Sec. 6 pp. 391-2 Volume 3
Wu and Manber, ``AGREP--A Fast Approximate Pattern-Matching Tool''