./my_script dora 09 30 2013-02-26

#!/bin/bash
# set -vx

f1()    {
         echo $1 $2 $3 $4                                       # put your function here
        }


case $# in
        0)      echo -e "# comment1\n# comment2" > list_file    # create list_file as desired
                read -p "Please fill in this list_file: "       # prompt as desired, read answer
                echo $REPLY                                     # do whatever with the user's reply
                ;;
        1)      [ -f "$1" ] || exit                             # check if file exists; otherwise exit
                grep -v '^#' "$1" |                             # do what you did before
                        while read arg1 arg2 arg3 arg4
                                do f1 $arg1 $arg2 $arg3 $arg4
                                done
                ;;
        4)      echo -e "# comment1\n# comment2" > list_file    # create list_file as desired
                echo $1 $2 $3 $4 >> list_file                   # put your function here
                ;;
        5)      echo -e "# comment1\n# comment2" > $1           # create file with $1 file name as desired
                shift
                f1 $1 $2 $3 $4 >> "$1"                   # put your function here
                ;;

        *)      echo "error msg"; exit
esac