Shell Programming and Scripting

I am very new to shell scripting. please help me in this scenario.

when we run the script, It should ask user to enter the input (for example, ticket number like below)

B1234567
B2345678
C1245782
.
2. Once user enter the input or,paste the input, the script should check each and every row, the lenght of the row should not exceed 8 characters, if it exceeds, script has to throw an error like "invalid input"..

3, if each and every have less than or equal to 8 character, script has to save the input to one text file..


This is my scenario, please help me to get it done.
Thanks in advance

sorry for my bad english

This is a simple shell script showing one way:

Code:

$ cat enter_ticket_number.sh
output_file="$1"
while true
  do
    # Ask the question
    read -p "Enter a ticket number: " REPLY

    # Any thing entered?
    if [ -z "$REPLY" ]; then
      echo "invalid ticket number, retry."
    fi

    # exit?
    if [ "$REPLY" = "x" ]; then
     exit
    fi

    # Check if the ticket number is valid
    if [ ${#REPLY} -gt 8 ]; then
      echo "invalid ticket number, retry."
    fi

    echo $REPLY >> $output_file
  done

Run script passing in file name to add ticket numbers to:

Code:

$ enter_ticket_number.sh /tmp/tickets.txt