CODEWITHSUNDEEP
searchawkgrep
upendra
upendra

Reputation: 2189

multiline search pattern in linux

I am trying to use grep to perform multiline search in linux but having problem with it. Basically i want to extract all the lines that follows with Sequences string in the below example.

Query= BRNW_157
Sequences producing significant alignments:                          (Bits)  Value
Query= BRNW_428
Query= BRNW_503
Sequences producing significant alignments:                          (Bits)  Value
Query= BRNW_601
Query= BRNW_617
Sequences producing significant alignments:                          (Bits)  Value

I tried awk but it doesn't work... awk '/Query=*/,/Sequences*/' and then i used grep and it doesn't work either...grep -PZo 'Query=*\n.*sequences'. Is there a way to go around this problem?

Upvotes: 0

Views: 223

Answers (2)

Ed Morton
Ed Morton

Reputation: 204638

Are you saying you want to find the word Sequences and print that line plus the line before it?

That'd just be:

awk '/Sequences/{print prev ORS $0} {prev=$0}' file

Upvotes: 1

iruvar
iruvar

Reputation: 23394

You are probably looking for

grep -oPz '(?ms)Query=(?:(?!Query).)*?Sequences.*?$'

This passes PCRE MULTILINE and DOTALL flags via the (?ms) and picks out each segment from a Query line to the next Sequences line.

Additionally, the -z flag passed to forces it to treat NUL as line-separator, ,making the contents of the file appear as a single string to it.

Upvotes: 1

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