Padraig Brady wrote: > How about: > > find /path/of/indexfile /dir/to/scan -type f | xargs cat | tr -cs > "[:alnum:]-" "\n" | sort | uniq -u Following should be better (allows ' in words and ignores case differences): find /path/of/indexfile /dir/to/scan -type f | xargs cat | tr -cs "[:alnum:]-'" "\n" | sort -f | uniq -iu Padraig