CODEWITHSUNDEEP
awksedgrep
Caterina
Caterina

Reputation: 987

Find line that matches a substring, then print THAT line and the following

I am trying to find the line containing string 7KFF_1 in a file. I want to print the line where it's located and the line right after. I tried this but I am not sure where I went wrong

awk '/7KFF_1/ { header = $0; next } { print header"\n"$0 }' sample.txt

NOTICE! I DON'T want to print the n lines after a match! I would like the current line where the match was made and the line right after that.

Upvotes: 2

Views: 907

Answers (3)

sseLtaH
sseLtaH

Reputation: 11237

grep or sed if applicable?

grep -A1 '7KFF_1' file

will print the line and 1 Line after as too would

sed -n '/7KFF_1/{N;p}' file

Upvotes: 3

William Pursell
William Pursell

Reputation: 212484

Use a flag. If the flag is set, print the line (to print the line after the match). Then assign the flag depending on if the current line matches. Then print if the flag is set (to print the line that matches.)

awk 'f; {f = /7KFF_1/}; f' sample.txt

You can simplify this to:

awk 'f; f = /7KFF_1/' sample.txt

but I thought that was a bit too obscure for the initial presentation.

Upvotes: 1

ilam engl
ilam engl

Reputation: 1570

Try this:

sed -n '/pattern/,$p' YOUR_FILE | head -2

The first part prints all lines after the pattern, then pipe it to head -2 printing the line containing your pattern AND the following line.

Upvotes: 2

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