xref: /freebsd/lib/libc/gen/getpass.3 (revision a220d00e74dd245b4fca59c5eca0c53963686325)
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32.\"     @(#)getpass.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd June 4, 1993
36.Dt GETPASS 3
37.Os
38.Sh NAME
39.Nm getpass
40.Nd get a password
41.Sh LIBRARY
42.Lb libc
43.Sh SYNOPSIS
44.In pwd.h
45.In unistd.h
46.Ft char *
47.Fn getpass "const char *prompt"
48.Sh DESCRIPTION
49The
50.Fn getpass
51function displays a prompt to, and reads in a password from,
52.Pa /dev/tty .
53If this file is not accessible,
54.Fn getpass
55displays the prompt on the standard error output and reads from the standard
56input.
57.Pp
58The password may be up to _PASSWORD_LEN (currently 128)
59characters in length.
60Any additional
61characters and the terminating newline character are discarded.
62.Pp
63The
64.Fn getpass
65function turns off character echoing while reading the password.
66.Sh RETURN VALUES
67The
68.Fn getpass
69function returns a pointer to the null terminated password.
70.Sh FILES
71.Bl -tag -width /dev/tty -compact
72.It Pa /dev/tty
73.El
74.Sh SEE ALSO
75.Xr crypt 3
76.Sh HISTORY
77A
78.Fn getpass
79function appeared in
80.At v7 .
81.Sh BUGS
82The
83.Fn getpass
84function leaves its result in an internal static object and returns
85a pointer to that object.
86Subsequent calls to
87.Fn getpass
88will modify the same object.
89.Pp
90The calling process should zero the password as soon as possible to
91avoid leaving the cleartext password visible in the process's address
92space.
93.Pp
94Upon receipt of a SIGTSTP, the input buffer will be flushed, so any
95partially typed password must be retyped when the process
96continues.
97