Question

I have a text file and am trying to extract the data in the first row (or line) of the file, where each data is saved as a list (so each point is saved on it’s own line) in a new file.

example data.txt:

Name  Col  Samp1  Samp2  Samp3  Samp4  Samp5  Samp6
Car1  Red   49.3   43.2   54.3   52.3   12.5   76.8
Car2  Blu   56.3   12.4   85.4   67.1   24.5   32.5
and so on..

I would like a new list to look like this, and saved to a new file called samps.txt:

Samp1
Samp2
Samp3
Samp4
Samp5
Samp6

I am very new to shell scripting and could use all the help anyone can provide.

Answer 1

Read the first line into a variable

read -r FIRSTLINE < filename

Split the string into words

WORDS=( $FIRSTLINE )

Loop through the words and output them to a file

for WORD in ${WORDS[@]}
do
  echo $WORD >> outputfilename
done

In your case, you want to drop the first two column values. You can slice the array by using ${WORDS[@]:2 in your for statement. Alternative, you can test the values inside the for loop before echoing them to the file.