how to flush lines that do NOT include characters 'FK'

how to flush lines that do NOT include characters 'FK'

[Roland Reichenberg]

Hi NG,

in my buffer, I want to flush all lines that do NOT contain the letters "FK"

My buffer contains lots of lines like:
laksjdfh
oqwirutz
095876
mxvb
aelkdjfFKddd
dffff
kkkkss
kkssss
aeskldjfopqirt
iquirmvqkrik
owuiertznvc
q9prskladhf
FK_hhh20894
1s9845FK01
095678jf
ajfhlakjdfh

>From these lines I want to filter the follwing
aelkdjfFKddd
FK_hhh20894
1s9845FK01

Any suggestions for a REGEXP?

I have tried the following:
M-x flush-lines [^FK]

But without success.

Who can help?

Thanks in advance,

        Roland

Re: how to flush lines that do NOT include characters 'FK'

[lawrence mitchell]

Roland Reichenberg wrote:

> in my buffer, I want to flush all lines that do NOT contain the letters "FK"

[...]

> Any suggestions for a REGEXP?

> I have tried the following:
> M-x flush-lines [^FK]

Writing regexps for matching "not something" is generally quite
difficult, especially if "something" is more than a single
character.  Instead, I suggest you look to try and keep all
lines containing the letters "FK".  Thankfully such a function
already exists.  So you can do:

M-x keep-lines RET FK RET

and not have to worry about nasty regexps :)

-- 
lawrence mitchell <wence@gmx.li>

Re: how to flush lines that do NOT include characters 'FK'

[Roland Reichenberg]

Hi lawrence,

> M-x keep-lines RET FK RET

was what I was looking for! Thank you very much!

Roland