shell script: read lines from file in a while loop

• by piping cat:

  cat /path/to/file | while read line
  do
      echo $line
  done
  

• by redirecting the file:

  while read line
  do
      echo $line
  done < /path/to/file
  

• by using awk:

  awk '{print $0}' /path/to/file
  

• by using head an tail:

  f=/path/to/file
  total=$(wc -l $f)
  n=0
  while [ $n -lt $total ]
  do
      let n++
      line=$(head -n $n $f | tail -1)
      echo ${line}
  done