Shell Programming and Scripting

#!/bin/sh

R='\033[0;31m'
N='\033[0m'

echo " ";
echo -e "${R}Choose database $N"
echo " ";
echo "1 - db_a"
echo "2 - db_b"
echo "3 - db_c"
echo "4 - db_g"
echo "5 - db_o"
echo "6 - db_e"
echo "7 - db_k"
echo "8 - db_t"
echo " "


read NUM

case $NUM in
       1)
                export ORACLE_SID=db_a
                export HOST=db_a_qa
                 ;;
       2)
		export ORACLE_SID=db_b
                export HOST=db_b_qa
                ;;
       3)
		export ORACLE_SID=db_c
                export HOST=db_c_qa
                ;;
       4)
		export ORACLE_SID=db_g
                export HOST=db_g_qa
                ;;
       5)
		export ORACLE_SID=db_o
                export HOST=db_o_qa
                 ;;
       6)
		export ORACLE_SID=db_e
                export HOST=db_e_qa
                ;;
       7)
		export ORACLE_SID=db_k
                export HOST=db_k_qa
                ;;
       8)
		export ORACLE_SID=db_t
                export HOST=db_t_qa
                ;;

       *) echo -e  "${R}Invalid number!${N}" 
				;;
esac
echo " "

#!/bin/sh

R='\033[0;31m'
N='\033[0m'

OPTIONS="1 - db_a
2 - db_b
3 - db_c
4 - db_g
5 - db_o
6 - db_e
7 - db_k
8 - db_t"
set -- $OPTIONS

printf "${R}Choose database ${N}\n\n%s\n\n" "$OPTIONS"

read NUM
case $NUM in 
   [1-8]) 
                eval export ORACLE_SID=\$\{$((3*NUM))\}
                export HOST=${ORACLE_SID}_qa
                ;;

       *)       printf "${R}Invalid number!${N}\n"
                ;;
esac
echo

#!/bin/bash

OPTIONS="db_a db_b db_c db_g db_o db_e db_k db_t"
PS3="Choose database: "
select ORACLE_SID in $OPTIONS; do echo $ORACLE_SID; HOST=${ORACLE_SID}_qa; echo $HOST; done
2) db_b
3) db_c
4) db_g
5) db_o
6) db_e
7) db_k
8) db_t
Choose database: 4
db_g
db_g_qa
Choose database: 8
db_t
db_t_qa
Choose database:

#!/bin/bash
R=$'\e[0;31m'
N=$'\e[0m'

OPTIONS=( db_a db_b db_c db_g db_o db_e db_k db_t )
PS3=$'\n'"${R}Choose database ${N}"

select ORACLE_SID in "${OPTIONS[@]}"; do
  if [[ $REPLY == [1-8] ]]; then
    export ORACLE_SID
    export HOST=${ORACLE_SID}_qa
    break
  fi
  printf "${R}Invalid number!${N}\n"
done 
echo

PS3=$(printf $'\n'"${R}Choose database ${N}")

$ R=$'\e[0;31m'; N=$'\e[0m'; var=$'\n'"${R}Choose database ${N}" dash -c 'echo "$var"'

Choose database