How do I echo stars (*) when reading password with `read`?

Question

What do I need to do for code in Bash, if I want to echo *s in place of password characters (or even just hide the characters completely) when the user types so

Answer 1

#!/bin/bash
echo "------------------------------"

n=7
echo " Enter Password :"

for (( i=1;i<n;i++ ))
do
    stty -echo
    read -r -s -n 1 char
    stty echo

    echo -n "*"
    pass+="$char"

done

echo " "
echo " Your password : $pass "

echo ""
echo "-------------------------------"

Answer 2

I really liked the answer that Wirone gave, but I didn't like that the backspacing would continue removing characters even back into the "Enter password: " prompt.

I also had some issues where pressing keys too rapidly would cause some of the characters to actually print on the screen... never a good thing when prompting for a password. =)

The following is my modified version of Wirone's answer which addresses these issues:

#!/bin/bash

unset PASSWORD
unset CHARCOUNT

echo -n "Enter password: "

stty -echo

CHARCOUNT=0
while IFS= read -p "$PROMPT" -r -s -n 1 CHAR
do
    # Enter - accept password
    if [[ $CHAR == $'\0' ]] ; then
        break
    fi
    # Backspace
    if [[ $CHAR == $'\177' ]] ; then
        if [ $CHARCOUNT -gt 0 ] ; then
            CHARCOUNT=$((CHARCOUNT-1))
            PROMPT=$'\b \b'
            PASSWORD="${PASSWORD%?}"
        else
            PROMPT=''
        fi
    else
        CHARCOUNT=$((CHARCOUNT+1))
        PROMPT='*'
        PASSWORD+="$CHAR"
    fi
done

stty echo

echo $PASSWORD

Answer 3

I don't know about stars, but stty -echo is your friend:

 #!/bin/sh 
 read -p "Username: " uname 
 stty -echo 
 read -p "Password: " passw; echo 
 stty echo

Source: http://www.peterbe.com/plog/passwords-with-bash

Answer 4

I would like to add something to Dennis Williamson's solution:

#!/bin/bash

unset password
echo -n "Enter password: "
while IFS= read -p "$prompt" -r -s -n 1 char
do
    # Enter - accept password
    if [[ $char == $'\0' ]] ; then
        break
    fi
    # Backspace
    if [[ $char == $'\177' ]] ; then
        prompt=$'\b \b'
        password="${password%?}"
    else
        prompt='*'
        password+="$char"
    fi
done

In above example script handles backspace correctly.

Source