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I am looping through a list of files, extracting the final line, and printing out columns 8, 9, and 10. I need to also print to the output the 'event number', which is essentially the total number of records being processes (NR). How do I print the event/record number in the first column, outputting to the output file, such as what I have below?

for i in `ls -d *mcp`; do
tail -1 "$i" | awk  '{ printf "%s %s %s\n", $8, $9, $10}' >> ${Pout}${output}
done
echo "Finished Looping through each file."

What I want as the output is:

1 45 60 5
2 30 67 3
3 40 12 4
.
.
.

where the '45 column represents $8, 60 represents $9, and 5 represents $10. the 1,2,3, etc. is what I need to output. I essentially need to print the line number.

geeb.24
  • 207
  • When I use this for loop structure:
    for i inls -d *mcp; do tail -1 "$i" | awk '{ printf "%d %s %s %s\n",NR, $8, $9, $10}' >> ${Pout}${output} done

    I get the following output: 1 -0.242 125.104 35.0 1 -6.308 151.717 28.1 1 13.764 144.429 130.0 1 -56.022 -27.779 109.3 1 -9.461 156.412 4.0

    Instead of all ones in the first column I want 1,2,...n. Does that clear things up?

     – geeb.24 May 13 '15 at 19:30
  • I understand your suggestion. However, that line in my for loop was working for me, which is why I didn't change it. Yes, it may be longer than what you wrote, but I didn't change it because it did what I needed it to do. – geeb.24 May 13 '15 at 19:35
  • Using backtics and ls means you are using two unnecessary processes. See whether my proposals below work for you. – Janis May 13 '15 at 19:43
  • (1) Don’t parse the output of ls.  for i in \ls -d mcp`` isn’t just inefficient; it produces wrong results* if filenames contain certain special characters.  (2) Don’t post multi-line commands or output in comments.  Clarifications to the question, to include things that you’ve tried, results that you’ve gotten, and results that you want, belong in the question — [edit] the question to put them there.  (3) When you do use command substitution, use $(…) instead of \…``.  (4) If you must display a \`` in code in a comment, type\``. – G-Man Says 'Reinstate Monica' May 14 '15 at 09:37

2 Answers2

1

With GNU awk (version 4.x) try this:

awk 'ENDFILE { printf "%d %s %s %s\n", ++c, $8, $9, $10}' *mcp > "${Pout}${output}"

echo "Finished Looping through each file."

With other awks and shells like bash try:

for f in *mcp
do
    awk -v c="$((++c))" 'END { printf "%d %s %s %s\n", c, $8, $9, $10}' "$f"
done > "${Pout}${output}"

echo "Finished Looping through each file."
Janis
  • 14,222
1

Try this:

for i in ./*.mcp; do
    if [ -f "$i" ]; then
        tail -1 "$i"
    fi
done | awk '{ print NR, $8, $9, $10 }'
lcd047
  • 7,238