xref: /freebsd/lib/libc/gen/getpass.3 (revision 2008043f386721d58158e37e0d7e50df8095942d)
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28.\"     @(#)getpass.3	8.1 (Berkeley) 6/4/93
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30.Dd June 4, 1993
31.Dt GETPASS 3
32.Os
33.Sh NAME
34.Nm getpass
35.Nd get a password
36.Sh LIBRARY
37.Lb libc
38.Sh SYNOPSIS
39.In pwd.h
40.In unistd.h
41.Ft char *
42.Fn getpass "const char *prompt"
43.Sh DESCRIPTION
44The
45.Fn getpass
46function displays a prompt to, and reads in a password from,
47.Pa /dev/tty .
48If this file is not accessible,
49.Fn getpass
50displays the prompt on the standard error output and reads from the standard
51input.
52.Pp
53The password may be up to _PASSWORD_LEN (currently 128)
54characters in length.
55Any additional
56characters and the terminating newline character are discarded.
57.Pp
58The
59.Fn getpass
60function turns off character echoing while reading the password.
61.Sh RETURN VALUES
62The
63.Fn getpass
64function returns a pointer to the null terminated password.
65.Sh FILES
66.Bl -tag -width /dev/tty -compact
67.It Pa /dev/tty
68.El
69.Sh SEE ALSO
70.Xr crypt 3 ,
71.Xr readpassphrase 3
72.Sh HISTORY
73A
74.Fn getpass
75function appeared in
76.At v7 .
77.Sh BUGS
78The
79.Fn getpass
80function leaves its result in an internal static object and returns
81a pointer to that object.
82Subsequent calls to
83.Fn 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.Pp
90Upon receipt of a SIGTSTP, the input buffer will be flushed, so any
91partially typed password must be retyped when the process
92continues.
93