How to do a loop through two columns in bash linux [duplicate]

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
– William Pursell, Commented Apr 5, 2022 at 12:45
Also, there's no need to use cat; you can write $(tr -d '\r' < /path/file.txt) — William Pursell
– William Pursell, Commented Apr 5, 2022 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 — Stephen Ostermiller
– Stephen Ostermiller ♦, Commented Apr 5, 2022 at 12:53

William Pursell · Accepted Answer · 2022-04-05 12:47:58Z

2

It looks like you want:

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

answered Apr 5, 2022 at 12:47

William Pursell

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1 Comment

Probably also add read -r in case the data contains backslashes.