AppleScript for user input

#!/bin/bash

/usr/bin/osascript <<EOT

  set theResponse to display dialog "What's your code?" default answer "" with icon stop buttons {"Cancel", "Continue"} default button "Continue" with hidden answer

display dialog "My Secret Code is " & (text returned of theResponse) & "."

EOT

OR

#!/bin/bash

HWNAME=$(osascript <<EOD
tell application "System Events"
text returned of (display dialog "Please enter your desired hostname: (Use dashes for spaces)" default answer "")
end tell
EOD)

scutil --set ComputerName "$HWNAME"
scutil --set LocalHostName "$HWNAME"
dscacheutil -flushcache