Question

I want to copy lines from one file to another:

count=1
while read -r i
do    
    echo $i
    (( count++ ))
done < "file1" > file2

but I don’t get any leading spaces in lines in file 2 if they were in file1.

Answer 1

This is because the value of IFS (internal field separator) will strip out those spaces. By default it separates based on spaces and newlines, I believe. A way around this is to temporarily set IFS equal to a newline.

#!/bin/bash

IFS="
"

count=1

while read -r i || [[ -n "$i" ]]
do
    echo $i 
    (( count++ ))
done < "file1" > file2

unset IFS