Access control after telnet

Question

Hi Pros,
I have been thinking and finding solution about how to configure the telent to run a script once user login to linux server vi telnet.
the expected result after login are as below, there is a message shown
1.FolderA
2.FolderB
3.Execute C
4.Exit
User only have to choose the number 1~9 to access the folder or run the script, they don't have the chance or permission to cd/ls..., not alone create folder.
Please advise how can I implement it.
thanks a lot
Henry

Answer 1

Wondering about your question to disable Ctrl-C.... Do you actually mean to script a telnet login to choose from a menu option, or to create a interacive menu that is shown to the user at login?
For instance:
#!/bin/sh
ctrl_c() {
    echo "Press 3 to exit"
opt1 () {
   cd /home/A
opt2 () {
   cd /home/B
trap ctrl_c INT
quit="no"
while [ $quit != "yes" ]
do
   echo "1. Folder A"
   echo "2. Folder B"
   echo "3. Quit"
   echo -n "Your choice? : "
   read choice
   case $choice in
      1) opt1 ;;
      2) opt2 ;;
      3) quit="yes" ;;
      *) echo "\"$choice\" is not valid"
          sleep 2 ;;
   esac
done