xref: /freebsd/lib/libc/gen/getpass.3 (revision d82e286489da73321a47e329d98a98817b0438b6)
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32.\"     @(#)getpass.3	8.1 (Berkeley) 6/4/93
33.\"
34.Dd June 4, 1993
35.Dt GETPASS 3
36.Os
37.Sh NAME
38.Nm getpass
39.Nd get a password
40.Sh SYNOPSIS
41.Fd #include <pwd.h>
42.Fd #include <unistd.h>
43.Ft char *
44.Fn getpass "const char *prompt"
45.Sh DESCRIPTION
46The
47.Fn getpass
48function displays a prompt to, and reads in a password from,
49.Pa /dev/tty .
50If this file is not accessible,
51.Nm getpass
52displays the prompt on the standard error output and reads from the standard
53input.
54.Pp
55The password may be up to _PASSWORD_LEN (currently 128)
56characters in length.
57Any additional
58characters and the terminating newline character are discarded.
59.Pp
60.Nm Getpass
61turns off character echoing while reading the password.
62.Pp
63.Sh RETURN VALUES
64.Nm Getpass
65returns a pointer to the null terminated password.
66.Sh FILES
67.Bl -tag -width /dev/tty - compact
68.It Pa /dev/tty
69.El
70.Sh SEE ALSO
71.Xr crypt 3
72.Sh HISTORY
73A
74.Nm getpass
75function appeared in
76.At v7 .
77.Sh BUGS
78The
79.Nm getpass
80function leaves its result in an internal static object and returns
81a pointer to that object.
82Subsequent calls to
83.Nm getpass
84will modify the same object.
85.Pp
86The calling process should zero the password as soon as possible to
87avoid leaving the cleartext password visible in the process's address
88space.
89