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.\" $DragonFly: src/lib/libc/gen/getpass.3,v 1.3 2007/09/08 20:50:49 swildner Exp $ 35.\" 36.Dd June 4, 1993 37.Dt GETPASS 3 38.Os 39.Sh NAME 40.Nm getpass 41.Nd get a password 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In pwd.h 46.In unistd.h 47.Ft char * 48.Fn getpass "const char *prompt" 49.Sh DESCRIPTION 50The 51.Fn getpass 52function displays a prompt to, and reads in a password from, 53.Pa /dev/tty . 54If this file is not accessible, 55.Fn getpass 56displays the prompt on the standard error output and reads from the standard 57input. 58.Pp 59The password may be up to 60.Dv _PASSWORD_LEN 61(currently 128) characters in length. 62Any additional 63characters and the terminating newline character are discarded. 64.Pp 65The 66.Fn getpass 67function turns off character echoing while reading the password. 68.Sh RETURN VALUES 69The 70.Fn getpass 71function returns a pointer to the null terminated password. 72.Sh FILES 73.Bl -tag -width /dev/tty -compact 74.It Pa /dev/tty 75.El 76.Sh SEE ALSO 77.Xr crypt 3 , 78.Xr readpassphrase 3 79.Sh HISTORY 80A 81.Fn getpass 82function appeared in 83.At v7 . 84.Sh BUGS 85The 86.Fn getpass 87function leaves its result in an internal static object and returns 88a pointer to that object. 89Subsequent calls to 90.Fn getpass 91will modify the same object. 92.Pp 93The calling process should zero the password as soon as possible to 94avoid leaving the cleartext password visible in the process's address 95space. 96.Pp 97Upon receipt of a 98.Dv SIGTSTP , 99the input buffer will be flushed, so any 100partially typed password must be retyped when the process 101continues. 102