Blob Blame History Raw
#!/bin/sh
# \
exec expect "$0" ${1+"$@"}
#
# Name: getpassck
#
# Description:
#    This script demonstrates when programs using getpass sometimes
#    fail.  The reason is that some implementations of getpass prompt
#    before the pty/tty has completed the switch to no-echo.  This may
#    not be obvious from examination of the implementation of getpass
#    itself because the driver itself may cut corners and be
#    responsible for allowing the call to return prematurely.
#
# Directions:
#   Simply run this script.  It will loop 100 times attempting to
#   generate the getpass problem.  If the bug cannot be reproduced,
#   you will see 100 failed attempts to su.  If the bug can be
#   reproduced, the script exits as soon as it is detected.
#
# Author: Don Libes <don@libes.com>
# Version: 1.0, Wed Mar  9 12:36:12 EST 2005
# 

for {set i 0} {$i < 100} {incr i} {
 spawn -noecho su
 expect ": "      ;# get password prompt as quickly as possible
 send "X\r"       ;# send password
 expect X {
  puts "Password was echoed!  This system has the getpass problem."
  exit
 } "orry" {
  close
  wait
 }
}
puts "Failed to reproduce getpass problem."