CODEWITHSUNDEEP
linuxbashawksed
xyz123
xyz123

Reputation: 651

How can I print the nth (5th) line of every file preceded by the FILENAME using any linux tool?

So my goal is to extract the fifth line of every file in my directory. I have a bunch of extension (*.gjf) files in my directory, and on the fifth line is always "1 0" or "1 1" without the quotes.

So far I know that I can extract those values but not with the filenames attached to them. This is the code I've been using. 

    awk 'FNR == 5' *.gjf
1  1
0  1
0  1
1  1
1  1
0  1

I desire my parsed files to look like this specifically. 

FILNAME: 1AH7A_TRP-16-A_GLU-9-A.gjf, 1, 1,
FILNAME: 1AH7A_TRP-198-A_ASP-197-A.gjf, 1 , 1,
FILNAME: 1BGFA_TRP-43-A_GLU-44-A.gjf, 0,  1,
FILNAME: CXQA_TRP-61-A_ASP-82-A.gjf, 1, 1,

I'd like the filenames to precede these values because I want to run statistics on these files as comma separated value files in R (and I am very capable to do that), and it's very important to me that I can prove that there are only two patterns in my files, the patterns being ordered "0 1" and "1 0".

I even tried listing the files

I tried doing this: 

grep -l "" *.gjf | awk 'FNR == 5' *.gjf

since I knew that I could grep the existence of the files and that would print the list to the screen. But I think I just passed it to awk, and so it computed.

1 1
1 1
0 1
1 1 
etc ...

I think that it just passed the files to awk and so it printed the nth line. I tried using && instead of |, and it just printed a complete list of the files and then a complete list of the numbers in no organized fashion. Clearly I don't know how to do this.

Upvotes: 2

Views: 1073

Answers (2)

glenn jackman
glenn jackman

Reputation: 246754

With GNU awk

gawk -v OFS=", " 'FNR == 5 {print "FILENAME: " FILENAME, $1, $2; nextfile}' *.gjf

Yes, FILENAME is the awk variable containing the current filename being processed.

Upvotes: 4

codeforester
codeforester

Reputation: 42999

Use this loop:

for file in *.gjf; do
  echo "FILENAME: $file, " $(sed 's/ /,/;s/$/,/;5q;d' "$file")
done
  • sed '5q;d' extracts the 5th line

Upvotes: 1

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