CODEWITHSUNDEEP
linuxbashawksed
missingNO
missingNO

Reputation: 1

Extract all lines between two patterns, containing at least one occurence of one string

I have a large file stored in a bash variable as a string, and i need to extract all the lines between two same words. But I also need to check if between these lines, I have at least one occurence of magicstring. Here's an example :

abc
xxxxxxxx
yyyyyyyy

abc
magicstring
kkkkkkkk
magicstring

abc
mmmmmmmm
nnnnnnnn

What I am looking for is the following :

magicstring
kkkkkkkk
magicstring

The two same words are always abc, but using sed, awk or even parameter expansion, how could I precise that I need the word magicstring contained at least once in those lines ?

I am assuming that I don't know the section where magicstring is contained, since it's a large file. EDIT : Also, magicstring appears only once or multiple times in only one section.

Using sed for example, I would get all the lines like this : sed '/abc/,/abc/{//!d}' <<<($myFileInVar) but I don't know to precise the need of magicstring.

Upvotes: 0

Views: 65

Answers (2)

Ed Morton
Ed Morton

Reputation: 203532

Using any awk in any shell on every UNIX box:

$ awk -v RS= -v ORS='\n\n' '/magicstring/' file
abc
magicstring
kkkkkkkk
magicstring

$ awk -v RS= -v ORS='\n\n' '/magicstring/{sub(/^[^\n]+\n/,""); print}' file
magicstring
kkkkkkkk
magicstring

Upvotes: 1

karakfa
karakfa

Reputation: 67507

gawk to the rescue!

$ awk -v RS='(^|\n)abc\n' '/magicstring/' file

magicstring
kkkkkkkk
magicstring

define the delimiter word as the record separator, print the record if it matches the magic string.

Upvotes: 1

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