bash loop through file and output to file code example

Example 1: bash iterate over lines of a file

while read p; do
  echo "$p"
done <peptides.txt

Example 2: for loop in bash for files

#!/bin/bash
FILES=/path/to/*
for f in $FILES
do
  echo "Processing $f file..."
  # take action on each file. $f store current file name
  cat $f
done