Hiding user input on terminal in Linux script

Question

I have bash script like the following      bin bash  echo  Please enter your username   read username   echo  Please enter your password   read password    I want that when the user types the password on the terminal  it should not be displayed  or something like           should be displayed   How do I achieve this

User · Answer

Get Username and password

Make it more clear to read but put it on a better position over the screen

#!/bin/bash
clear
echo 
echo 
echo
counter=0
unset username
prompt="  Enter Username:"
while IFS= read -p "$prompt" -r -s -n 1 char
do
    if [[ $char == $'\0' ]]; then
        break
    elif [ $char == $'\x08' ] && [ $counter -gt 0 ]; then
        prompt=$'\b \b'
        username="${username%?}"
        counter=$((counter-1))
    elif [ $char == $'\x08' ] && [ $counter -lt 1 ]; then
        prompt=''
        continue
    else
        counter=$((counter+1))
        prompt="$char"
        username+="$char"
    fi
done
echo
unset password
prompt="  Enter Password:"
while IFS= read -p "$prompt" -r -s -n 1 char
do
    if [[ $char == $'\0' ]]; then
        break
    elif [ $char == $'\x08' ] && [ $counter -gt 0 ]; then
        prompt=$'\b \b'
        password="${password%?}"
        counter=$((counter-1))
    elif [ $char == $'\x08' ] && [ $counter -lt 1 ]; then
        echo
        prompt="  Enter Password:"
        continue
    else
        counter=$((counter+1))
        prompt='*'
        password+="$char"
    fi
done

User · Answer

Update In case you want to get fancy by outputting an   for each character they type  you can do something like this  using andreas  read -s solution   unset password  while IFS  read -r -s -n1 pass  do   if    -z  pass     then      echo      break   else      echo -n          password   pass   fi done  Without being fancy echo  quot Please enter your username quot   read username   echo  quot Please enter your password quot   stty -echo read password  stty echo

User · Answer

I always like to use Ansi escape characters   echo -e  Enter your password   x1B 8m  echo -e   x1B 0m    8m makes text invisible and 0m resets text to  normal   The -e makes Ansi escapes possible   The only caveat is that you can still copy and paste the text that is there  so you probably shouldn t use this if you really want security   It just lets people not look at your passwords when you type them in  Just don t leave your computer on afterwards        NOTE   The above is platform independent as long as it supports Ansi escape sequences   However  for another Unix solution  you could simply tell read to not echo the characters     printf  password    let pass   read -s  printf   nhey everyone  the password the user just entered is  pass n

User · Answer

Here is a variation of  SiegeX s answer which works with traditional Bourne shell  which has no support for    assignments    password    while IFS  read -r -s -n1 pass  do   if   -z   pass     then      echo      break   else      printf          password   password pass    fi done

User · Answer

Just supply -s to your read call like so     read -s PASSWORD   echo  PASSWORD

User · Answer

for a solution that works without bash or certain features from read you can use stty to disable echo  stty orig   stty -g  stty -echo read password stty  stty orig

User · Answer

A variation on both  SiegeX and  mklement0 s excellent contributions  mask user input  handle backspacing  but only backspace for the length of what the user has input  so we re not wiping out other characters on the same line  and handle control characters  etc    This solution was found here after so much digging     bin bash     Read and echo a password  echoing responsive  stars  for input characters   Also handles  backspaces  deleted and  U  kill-line  control-chars   unset PWORD PWORD  echo -n  password    1 gt  amp 2 while true  do   IFS  read -r -N1 -s char     Note a NULL will return a empty string     Convert users key press to hexadecimal character code   code   printf   02x   quot   char quot     EOL  empty char  - gt  00   case  quot  code quot  in      0a 0d  break        Exit EOF  Linefeed or Return   08 7f     backspace or delete       if   -n  quot  PWORD quot     then         PWORD  quot    echo  quot  PWORD quot    sed  s         quot          echo -n    b  b  1 gt  amp 2       fi            15     U or kill line       echo -n  quot  PWORD quot    sed  s    cH  cH g   gt  amp 2       PWORD                01                                Ignore ALL other control characters       PWORD  quot  PWORD char quot        echo -n     1 gt  amp 2            esac done echo echo  PWORD

User · Answer

A bit different from  but mostly like   lesmana s answer  stty -echo read password stty echo   simply  hide echo do your stuff show echo

User · Answer

Here s a variation on  SiegeX s excellent  -printing solution for bash with support for backspace added  this allows the user to correct their entry with the backspace key  delete key on a Mac   as is typically supported by password prompts      usr bin env bash  password    while IFS  read -r -s -n1 char  do      -z  char     amp  amp    printf   n   break      ENTER pressed  output  n and break    if     char       x7f      then   backspace was pressed         Remove last char from output variable           -n  password     amp  amp  password   password            Erase     to the left        printf   b  b     else       Add typed char to output variable      password   char       Print     in its stead      printf       fi done   Note     As for why pressing backspace records character code 0x7f   In modern systems  the backspace key is often mapped to the delete character  0x7f in ASCII or Unicode   https   en wikipedia org wiki Backspace  b  b is needed to give the appearance of deleting the character to the left  just using  b moves the cursor to the left  but leaves the character intact  nondestructive backspace   By printing a space and moving back again  the character appears to have been erased  thanks  The  quot backspace quot  escape character   39  b  39  in C  unexpected behavior        In a POSIX-only shell  e g   sh on Debian and Ubuntu  where sh is dash   use the stty -echo approach  which is suboptimal  because it prints nothing   because the read builtin will not support the -s and -n options

[linux] Hiding user input on terminal in Linux script

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