Shell Programming and Scripting

#!/bin/bash

clear
echo 'SeaBatch 2.0'
echo; echo
read -s -p 'Press <return> to continue'
clear

echo 'Processing parameters:' > seabatch_log.txt
echo >> seabatch_log.txt

VALID_PROCESS=0
while [ $VALID_PROCESS -eq 0 ]; do
    
    echo 'Do you want to PROCESS any files? (y or n)'
    
    read PROCESS
    
    case $PROCESS in
        y | n)
        VALID_PROCESS=1
        ;;
        v)
        $SEADAS'/seabatch1.1/cat_seabatch_log.sh'
        ;;
        q)
        clear
        exit 0
        ;;
        *)
        echo 'Invalid entry! Must be y or n'
        echo; echo
    esac
done

if [ $PROCESS = 'y' ]; then

    clear
    
    echo 'PROCESS=yes' >> seabatch_log.txt

    VALID_START_LEVEL=0
    
    while [ $VALID_START_LEVEL -eq 0 ]; do
    
        echo 'What is the START level of the data? (0, 1, or 2)'
        
        read START_LEVEL
        
        case $START_LEVEL in
            0 | 1 | 2)
            VALID_START_LEVEL=1
            ;;
            v)
            $SEADAS'/seabatch1.1/cat_seabatch_log.sh'
            ;;
            q)
            clear
            exit 0
            ;;
            *)
            echo 'Invalid entry! Must be 0, 1, or 2'
            echo; echo
        esac
    done    
fi