getpass - read a password
getpass() reads up to a NEWLINE or EOF from the file /dev/tty, or if
that cannot be opened, from the standard input, after prompting with
the null-terminated string prompt and disabling echoing. A pointer is
returned to a null-terminated string of at most 8 characters. An
interrupt will terminate input and send an interrupt signal to the
calling program before returning.
SYSTEM V DESCRIPTION
If /dev/tty cannot be opened, getpass() returns a NULL pointer. It
does not read the standard input.
The above routine uses <<stdio.h>>, which increases the size of programs
not otherwise using standard I/O, more than might be expected.
The return value points to static data whose content is overwritten by
6 October 1989 GETPASS(3V)