Print lines between (and including) two patterns

Question

I want to start grepping from the lines that has CK at the end of line and stop grepping when the line has D at the end. I tried grep "$CK" "$D" file..txt, but it didn't work.

Input:

kkkkkkkkkkk   
jjjjjjjjjjjjjjjjjj  
gggggggggggg/CK  
JHGHHHHHHHH   
HJKHKKLKLLL   
JNBHBHJKJJLKKL  
JLKKKLLKJLKJ/D  
GGGGGGGGGGGGGG  
GGGGGGGGGGGGGG

The desired output:

gggggggggggg/CK  
JHGHHHHHHHH   
HJKHKKLKLLL   
JNBHBHJKJJLKKL  
JLKKKLLKJLKJ/D

Solution

You are better off using awk or sed

awk '/CK$/,/D$/' file.txt

OR

sed -n '/CK$/,/D$/p' file.txt

If you insist on grep, here's a GNU grep way

grep -oPz '(?s)(?<=\n)\N+CK\n.*?D(?=\n)' file.txt

Here

-P activates perl-regexp

-z sets line separator to NUL. This forces grep to see the entire file as one single line

-o prints only matching

(?s) activates PCRE_DOTALL, so . finds any character or newline

\N matches anything except newline

.*? finds . in nongreedy mode

(?<=..) is a look-behind assertion

(?=..) is a look-ahead assertion

Comments

[Mathias Begert]

@RahulPatil, that's because the OP stated 'start grepping from the lines that has "CK" at the end of line and stop grepping when the line has "D"'

[Rahul Patil]

it seems me, you have strong understanding of regex.. I didn't understand that level, so could you please explain that last of PCRE grep

[Mathias Begert]

@RahulPatil, added some explanation :-)

[Rana Khan]

@RohitPatil, I want to delete the matching selection from the file. can i do that?

[Mathias Begert]

@RanaKhan, what does the first line come back stating when you run sed --version on your system?

[Rana Khan]

so basically the block that i want to remove has the first line that end with "CK \" and last line that end with "RD \". I am trying the following : sed -n '/CK \\$/,/D \\$/' script.tcl | more and it does not work , it says " sed: -e expression #1, char 16: missing command"

[Rana Khan]

this does not delete this block. it only shows it

[Mathias Begert]

let us continue this discussion in chat