Pause execution and wait for user input

Question

I have a script that I am making and I have an issue with it: I would like to pause execution and wait for user input. I thought that I had it with the read -p -n 1 $foo command but the system is having issues with this command. Here is my current script:

#!/bin/sh
Ititialization
mainmenu () {
  echo "Press 1 to update your system"
  echo "Press 2 to install samba"
  echo "Press 3 to install vsFTPd"
  echo "Press 4 to install the current version of Webmin"
  echo "Press 5 to configure samba for Active Directory"
  echo "Press x to exit the script"
  read -n 1 -p "Input Selection:" mainmenuinput
  if [ "$mainmenuinput" = "1" ]; then
            updatesystem
        elif [ "$mainmenuinput" = "2" ]; then
            installsamba
        elif [ "$mainmenuinput" = "3" ]; then
            installvsftpd
        elif [ "$mainmenuinput" = "4" ]; then
            installwebmin
        elif [ "$mainmenuinput" = "5" ]; then
            configuresambaforactivedirectory
        elif [ "$mainmenuinput" = "x" ];then
            quitprogram
        elif [ "$mainmenuinput" = "X" ];then
            quitprogram
        else
            echo "You have entered an invallid selection!"
            echo "Please try again!"
            echo ""
            echo "Press any key to continue..."
            read -n 1
            clear
            mainmenu
        fi
}
This builds the main menu and routs the user to the function selected.
mainmenu
This executes the main menu function.
Let the fun begin!!!! WOOT WOOT!!!!

You may notice at the mainmenu function the read -n 1 -p "text goes here" entry. That is where I am having the issue according to ubuntu. Can somebody tell me what is going wrong? thanks!

The shebang is wrong. You're using bash features, so the shebang must be set to #!/usr/bin/env bash or #!/bin/bash. — geirha, Apr 13 '14 at 12:01
Please also consider this Unix.SE question of mine, where read and sh (instead of bash) were also causing trouble. — Cadoiz, Nov 05 '21 at 13:25

score 79 · Accepted Answer · edited Mar 25 '16 at 17:06

79

Should be:

read  -n 1 -p "Input Selection:" mainmenuinput

Need to put the n flag after, as that is is telling read to execute after N characters are entered, do not wait for an entire line. Check help read and this for details.

edited Mar 25 '16 at 17:06

heemayl

91,753

answered Apr 10 '14 at 21:07

NGRhodes

9,490

2

I have figured it out! Here is the correct code: read -n 1 -p "Input Selection:" "mainmenuinput" It now does not wait for the press of the enter/return key :-) – Elliot Huffman Apr 13 '14 at 17:05
3

"illegal option -n" – ses May 14 '14 at 20:06
3

If you just want to pause execution and wait to continue in a for loop: for $whatever; do $whatever; read -n 1 -p Continue?; done – niken Feb 02 '17 at 17:00
1

@ses See my comment here – Cadoiz Nov 05 '21 at 13:29
1

If you want to hide the typed character you can add the -s option. – schlicki Jun 14 '22 at 11:21

Pause execution and wait for user input

Ititialization

This builds the main menu and routs the user to the function selected.

This executes the main menu function.

Let the fun begin!!!! WOOT WOOT!!!!

1 Answers1

Linked