xref: /original-bsd/lib/libc/gen/getpass.3 (revision ba762ddc)
1.\" Copyright (c) 1989, 1991 The Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" %sccs.include.redist.man%
5.\"
6.\"     @(#)getpass.3	6.4 (Berkeley) 04/21/91
7.\"
8.Dd
9.Dt GETPASS 3
10.Os
11.Sh NAME
12.Nm getpass
13.Nd get a password
14.Sh SYNOPSIS
15.Fd #include <unistd.h>
16.Ft char *
17.Fn getpass "const char *prompt"
18.Sh DESCRIPTION
19The
20.Fn getpass
21function displays a prompt to, and reads in a password from,
22.Pa /dev/tty .
23If this file is not accessible,
24.Nm getpass
25displays the prompt on the standard error output and reads from the standard
26input.
27.Pp
28The password may be up to 128 characters in length; any additional
29characters and the terminating newline character are discarded.
30.Pp
31.Nm Getpass
32turns off character echoing while reading the password.
33.Pp
34.Sh RETURN VALUES
35.Nm Getpass
36returns a pointer to the null terminated password.
37.Sh FILES
38.Bl -tag -width /dev/tty - compact
39.It Pa /dev/tty
40.El
41.Sh SEE ALSO
42.Xr crypt 3
43.Sh HISTORY
44A
45.Nm getpass
46function appeared in
47.At v7 .
48.Sh BUGS
49The
50.Nm getpass
51function leaves its result in an internal static object and returns
52a pointer to that object.
53Subsequent calls to
54.Nm getpass
55will modify the same object.
56.Pp
57The calling process should zero the password as soon as possible to
58avoid leaving the cleartext password visible in the process's address
59space.
60