1.\" $OpenBSD: getpass.3,v 1.8 2001/02/10 06:04:31 aaron Exp $ 2.\" 3.\" Copyright (c) 1989, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 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.Fn 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, as defined in 56the include file 57.Aq Pa pwd.h ) 58characters in length. 59Any additional 60characters and the terminating newline character are discarded. 61.Pp 62.Fn getpass 63turns off character echoing while reading the password. 64.Pp 65The calling process should zero the password as soon as possible to 66avoid leaving the cleartext password visible in the process's address 67space. 68.Sh RETURN VALUES 69.Fn getpass 70returns a pointer to the null-terminated password. 71.Sh FILES 72.Bl -tag -width /dev/tty -compact 73.It Pa /dev/tty 74.El 75.Sh SEE ALSO 76.Xr crypt 3 , 77.Xr readpassphrase 3 78.Sh HISTORY 79A 80.Fn getpass 81function appeared in 82.At v7 . 83.Sh BUGS 84The 85.Fn getpass 86function leaves its result in an internal static object and returns 87a pointer to that object. 88Subsequent calls to 89.Fn getpass 90will modify the same object. 91