1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)getpass.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/gen/getpass.3,v 1.6.2.4 2002/06/30 14:01:45 des Exp $ 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.Xr readpassphrase 3 77.Sh HISTORY 78A 79.Fn getpass 80function appeared in 81.At v7 . 82.Sh BUGS 83The 84.Fn getpass 85function leaves its result in an internal static object and returns 86a pointer to that object. 87Subsequent calls to 88.Fn getpass 89will modify the same object. 90.Pp 91The calling process should zero the password as soon as possible to 92avoid leaving the cleartext password visible in the process's address 93space. 94.Pp 95Upon receipt of a SIGTSTP, the input buffer will be flushed, so any 96partially typed password must be retyped when the process 97continues. 98