Wiktor Stribiżew
2020-11-20 20:57:29
You can use
grep -hEio '[[:alpha:]]*[b-df-hj-np-tv-z]{6}[[:alpha:]]*' *.txt
Regex details
[[:alpha:]]*- any zero or more letter[b-df-hj-np-tv-z]{6}- six English consonant letters on end[[:alpha:]]*- any zero or more letter.
The grep options make the regex search case insensitive (i) and grep shows the matched texts only (with o) without displaying the filenames (h). The -E option allows the POSIX ERE syntax, else, if you do not specify it, you would need to escape {6} as \{6\},
Why we need
[[:alpha:]]*before and after ?@Philippe To match any zero or more letters.
@Philippe See the online
grepdemo to see why[[:alpha:]]*is important here.