tags | word scape, wordscape
% grep -i "^[slev][slev][slev][slev]s$" /usr/share/dict/american-english elves sells
Remove lines with duplicate letters
% grep -Ei "^[hikers]{5}$" /usr/share/dict/american-english | grep -Eiv "(.).*\1"
...
shire
shirk
skier
compare this with
% grep -Ei "^[hikers]{5}$" /usr/share/dict/american-english
...
shire
shirk
shirr
sires
sises
skier
skies
which also shows words where some letters are repeated twice.
Use (character){N} and call grep with -E
% grep -Ei "^[enrich]i([enrich]){2}e$" /usr/share/dict/american-english
Circe
niche
niece
is equivalent to
% grep -i "^[enrich]i[enrich][enrich]e$" /usr/share/dict/american-english Circe niche niece
Another example:
% grep -Ei "^([dunes]){2}u([dunes]){2}d$" /usr/share/dict/american-english
unused
To print lines that contain less than N characters
grep -Ev ".{N}" data.txt
For example: To print lines that contain less then 6 characters
grep -Ev ".{6}" data.txt
You can also do
grep -v "......" data.txt
where the . is repeated N times. This is easier to type for small N.
Sample run:
$ cat data.txt
a
ab
abc
abcd
abcde
abcdef
abcdefg
$ grep -v "......" data.txt
a
ab
abc
abcd
abcde
$ grep -Ev ".{6}" data.txt
a
ab
abc
abcd
abcde