CODEWITHSUNDEEP
linuxbashshell
Kevin Char
Kevin Char

Reputation: 85

How do i stop text showing up when user types during execution of bash script?

You can see what problem I'm having just by doing sleep 10 and typing.

How would I go about stopping that typing from showing?

Upvotes: 3

Views: 1586

Answers (2)

Léa Gris
Léa Gris

Reputation: 19555

You could do this like that:

#!/usr/bin/env bash

exit_trap ()
{
  # Purge pending typed data if any
  # While there is data to read
  while read -rt0
  do IFS= read -r # read the data
  done < /dev/tty # from the tty terminal
  # Restore terminal echo
  stty echo
}

# If running from a terminal
if [ -t 1 ]
then
  # Program exit trap to cleanup and restore terminal echo on
  trap 'exit_trap' EXIT
  # Disable terminal echo
  stty -echo
fi

echo "going to sleep 5"
sleep 5
echo "finished sleeping"

Upvotes: 1

Anya Shenanigans
Anya Shenanigans

Reputation: 94644

To turn off keyboard echo, you can use stty -echo. To turn it back on you can do stty echo. To be safe, you would save the stty state and restore it at the end; however if you're reading a password, bash has a built-in -s option to read.

In summary:

stty -echo
# keyboard input is not echoed
stty echo
# keyboard input is echoed

More complete:

state=$(stty -g)
stty -echo
# keyboard is not echoed
stty "$state"
# state is restored.

Better, if you're just asking for a password, and using bash:

read -s password
# password is now in the variable $password; no stty shenanigans

Upvotes: 3

Related Questions