1.\" $NetBSD: umask.2,v 1.12 2002/04/29 01:41:46 simonb Exp $ 2.\" 3.\" Copyright (c) 1980, 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.\" @(#)umask.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt UMASK 2 38.Os 39.Sh NAME 40.Nm umask 41.Nd set file creation mode mask 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]sys/stat.h\*[Gt] 46.Ft mode_t 47.Fn umask "mode_t numask" 48.Sh DESCRIPTION 49The 50.Fn umask 51routine sets the process's file mode creation mask to 52.Fa numask 53and returns the previous value of the mask. The 9 low-order 54access permission 55bits of 56.Fa numask 57are used by system calls, including 58.Xr open 2 , 59.Xr mkdir 2 , 60.Xr mkfifo 2 61and 62.Xr mknod 2 63to turn off corresponding bits 64requested in file mode. 65(See 66.Xr chmod 2 ) . 67This clearing allows each user to restrict the default access 68to his files. 69.Pp 70The default mask value is S_IWGRP|S_IWOTH (022, write access for the 71owner only). 72Child processes inherit the mask of the calling process. 73.Sh RETURN VALUES 74The previous value of the file mode mask is returned by the call. 75.Sh ERRORS 76The 77.Fn umask 78function is always successful. 79.Sh SEE ALSO 80.Xr chmod 2 , 81.Xr mkdir 2 , 82.Xr mkfifo 2 , 83.Xr mknod 2 , 84.Xr open 2 85.Sh STANDARDS 86The 87.Fn umask 88function conforms to 89.St -p1003.1-90 . 90