The
getpass() function displays a prompt to, and reads in a password from,
/dev/tty. If this file is not accessible,
getpass() displays the prompt on the standard error output and reads from the standard input.
The password may be up to _PASSWORD_LEN (currently 128) characters in length. Any additional characters and the terminating newline character are discarded.
getpass() turns off character echoing while reading the password.