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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getpass.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/gen/getpass.3,v 1.6.2.4 2002/06/30 14:01:45 des Exp $ 30.\" $DragonFly: src/lib/libc/gen/getpass.3,v 1.3 2007/09/08 20:50:49 swildner Exp $ 31.\" 32.Dd June 4, 1993 33.Dt GETPASS 3 34.Os 35.Sh NAME 36.Nm getpass 37.Nd get a password 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In pwd.h 42.In 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.Fn getpass 52displays the prompt on the standard error output and reads from the standard 53input. 54.Pp 55The password may be up to 56.Dv _PASSWORD_LEN 57(currently 128) characters in length. 58Any additional 59characters and the terminating newline character are discarded. 60.Pp 61The 62.Fn getpass 63function turns off character echoing while reading the password. 64.Sh RETURN VALUES 65The 66.Fn getpass 67function returns a pointer to the null terminated password. 68.Sh FILES 69.Bl -tag -width /dev/tty -compact 70.It Pa /dev/tty 71.El 72.Sh SEE ALSO 73.Xr crypt 3 , 74.Xr readpassphrase 3 75.Sh HISTORY 76A 77.Fn getpass 78function appeared in 79.At v7 . 80.Sh BUGS 81The 82.Fn getpass 83function leaves its result in an internal static object and returns 84a pointer to that object. 85Subsequent calls to 86.Fn getpass 87will modify the same object. 88.Pp 89The calling process should zero the password as soon as possible to 90avoid leaving the cleartext password visible in the process's address 91space. 92.Pp 93Upon receipt of a 94.Dv SIGTSTP , 95the input buffer will be flushed, so any 96partially typed password must be retyped when the process 97continues. 98