Read from two files line by line and process them simultaneously

Question

Hello everyone I\'m very new to the game so my question is probably rather simple but I\'m stuck at this for a long time. I want to process two files from two list of files

Answer 1

You need two separate file descriptors to read from two files at once. One of them can be standard input.

while IFS= read -r line1 && IFS= read -r line2 <&3; do
  echo "File 1: $line1"
  echo "File 2: $line2"
done < file1 3< file2