Shell Programming and Scripting

tail -n 2 file.txt | sort -k 1

#!/bin/sh
stop="yes"
while [ $stop = "yes" ]
do
  printf "Select one (1/2/q): "
  read inputkey
  case $inputkey in
    1) echo "you sayed 1"
       tail -n 2 results.txt | sort -k 1;;
    2) echo "you sayed 2"
       tail -n 2 results.txt | sort -k 2;;
    q) echo "you sayed q"
       stop="no";;
    *) echo "You have to select between 1 and 2";;
  esac
done

Select one (1/2/q): 2
you sayed 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
Select one (1/2/q): You have to select between 1 and 2
...

case "$inputkey" in 
...

stop="yes"
while [ $stop = "yes" ]
do
  printf "Select one (0/1/2/q): "
  read inputkey
  case "$inputkey" in
    0) echo "you sayed 0"
       tail -n 2 results.txt;;
    1) echo "you sayed 1"
       tail -n 2 results.txt | sort -k 1;;
    2) echo "you sayed 2"
       tail -n 2 results.txt | sort -k 1;;
    q) echo "you sayed q"
       stop="no";;
    *) echo "You have to select between 1 and 2";;
  esac
done

stop="yes"
while [ $stop = "yes" ]
do
  printf "Select one (0/1/2/q): "
  read inputkey < /dev/tty
  case $inputkey in
    0) echo "you sayed 0"
       tail -n +2 results.txt;;
    1) echo "you sayed 1"
       set -x
       tail -n +2 results.txt | sort -k 2
       set +x;;
    2) echo "you sayed 2"
       tail -n +2 results.txt | sort -k 2;;
    q) echo "you sayed q"
       stop="no";;
    *) echo "You have to select between 1 and 2";;
  esac
done
exit

Select one (0/1/2/q): 1
you sayed 1
+ sort -k 2
stop=yes
+ [ yes = yes ]
+ printf Select one (0/1/2/q):
+ tail -n +2 results.txt
Select one (0/1/2/q): + read inputkey
q
+ echo you sayed q
you sayed q
stop=no
+ [ no = yes ]
+ exit
+ set +x
Select one (0/1/2/q): q
you sayed q
$

year month
1990 56
1991 1
1992 90

$  tail -n +2 results.txt | sort -k 2
1991 1
1990 56
1992 90
$