How to do a loop through two columns in bash linux

Question

I'm new in bash linux coding. Basically I would like to do a loop using a text file with two columns.

For a single column file I use this type of code:

for element in `cat /path/file.txt | tr -d '\r'`
do
operation on element
done

I would like to use the two elements of each line as argument for a function. So it would be like:

file.txt:

Column A	Column B
a	c
b	d

And the using in the same line of code the first row of column A and B, then the second row and go on...

I don't know if it is possible to use indexes to specify the row and column that I want for each iteration.

You are new to bash, so you may not be aware that `$()` has been preferred over backticks for at least a few decades. — William Pursell, Apr 05 '22 at 12:45
Also, there's no need to use `cat`; you can write `$(tr -d '\r' < /path/file.txt)` — William Pursell, Apr 05 '22 at 12:46
You want to read the file line by line using the solutions from [Looping through the content of a file in Bash](https://stackoverflow.com/questions/1521462/looping-through-the-content-of-a-file-in-bash) — Stephen Ostermiller, Apr 05 '22 at 12:53

score 1 · Accepted Answer · answered Apr 05 '22 at 12:47

1

It looks like you want:

tr -d '\r' < /path/file.txt | 
while read a b; do
  operate "$a" "$b"
done

answered Apr 05 '22 at 12:47

William Pursell

Probably also add `read -r` in case the data contains backslashes. – tripleee Apr 05 '22 at 18:23

1 Answers1