1.\" $OpenBSD: chflags.2,v 1.29 2022/08/04 06:20:24 jsg Exp $ 2.\" $NetBSD: chflags.2,v 1.6 1995/02/27 12:32:03 cgd Exp $ 3.\" 4.\" Copyright (c) 1989, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)chflags.2 8.1 (Berkeley) 6/9/93 32.\" 33.Dd $Mdocdate: August 4 2022 $ 34.Dt CHFLAGS 2 35.Os 36.Sh NAME 37.Nm chflags , 38.Nm chflagsat , 39.Nm fchflags 40.Nd set file flags 41.Sh SYNOPSIS 42.In sys/stat.h 43.Ft int 44.Fn chflags "const char *path" "unsigned int flags" 45.Ft int 46.Fn fchflags "int fd" "unsigned int flags" 47.In sys/stat.h 48.In fcntl.h 49.Ft int 50.Fn chflagsat "int fd" "const char *path" "unsigned int flags" "int atflags" 51.Sh DESCRIPTION 52The file whose name is given by 53.Fa path 54or referenced by the descriptor 55.Fa fd 56has its flags changed to 57.Fa flags . 58.Pp 59The flags are the bitwise OR of zero or more of the following values: 60.Pp 61.Bl -tag -width "SF_IMMUTABLE" -compact -offset indent 62.It Dv UF_NODUMP 63Do not dump the file. 64.It Dv UF_IMMUTABLE 65The file may not be changed. 66.It Dv UF_APPEND 67The file may only be appended to. 68.It Dv SF_ARCHIVED 69The file may be archived. 70.It Dv SF_IMMUTABLE 71The file may not be changed. 72.It Dv SF_APPEND 73The file may only be appended to. 74.El 75.Pp 76The 77.Dv UF_IMMUTABLE 78and 79.Dv UF_APPEND 80flags may be set or unset by either the owner of a file or the superuser. 81.Pp 82The 83.Dv SF_ARCHIVED , 84.Dv SF_IMMUTABLE 85and 86.Dv SF_APPEND 87flags may only be set or unset by the superuser. 88They may be set at any time, but normally may only be unset when 89the system is in single-user mode. 90(See 91.Xr init 8 92for details.) 93.Pp 94The 95.Fn chflagsat 96function is equivalent to 97.Fn chflags 98except in the case where 99.Fa path 100specifies a relative path. 101In this case the file to be changed is determined relative to the directory 102associated with the file descriptor 103.Fa fd 104instead of the current working directory. 105.Pp 106If 107.Fn chflagsat 108is passed the special value 109.Dv AT_FDCWD 110(defined in 111.In fcntl.h ) 112in the 113.Fa fd 114parameter, the current working directory is used. 115If 116.Fa atflags 117is also zero, the behavior is identical to a call to 118.Fn chflags . 119.Pp 120The 121.Fa atflags 122argument is the bitwise OR of zero or more of the following values: 123.Pp 124.Bl -tag -width AT_SYMLINK_NOFOLLOW -offset indent -compact 125.It Dv AT_SYMLINK_NOFOLLOW 126If 127.Fa path 128names a symbolic link, then the flags of the symbolic link are changed. 129.El 130.Pp 131The 132.Fn fchflags 133function is equivalent to 134.Fn chflags 135except that the file whose flags are changed is specified 136by the file descriptor 137.Fa fd . 138.Sh RETURN VALUES 139.Rv -std 140.Sh ERRORS 141.Fn chflags 142will fail if: 143.Bl -tag -width Er 144.It Bq Er ENOTDIR 145A component of the path prefix is not a directory. 146.It Bq Er ENAMETOOLONG 147A component of a pathname exceeded 148.Dv NAME_MAX 149characters, or an entire pathname (including the terminating NUL) 150exceeded 151.Dv PATH_MAX 152bytes. 153.It Bq Er ENOENT 154The named file does not exist. 155.It Bq Er EACCES 156Search permission is denied for a component of the path prefix. 157.It Bq Er ELOOP 158Too many symbolic links were encountered in translating the pathname. 159.It Bq Er EPERM 160The effective user ID does not match the owner of the file and 161the effective user ID is not the superuser, or the effective user ID 162is not the superuser and at least one of the super-user-only flags 163for the named file would be changed. 164.It Bq Er EOPNOTSUPP 165The named file resides on a file system that does not support file 166flags. 167.It Bq Er EROFS 168The named file resides on a read-only file system. 169.It Bq Er EFAULT 170.Fa path 171points outside the process's allocated address space. 172.It Bq Er EIO 173An I/O error occurred while reading from or writing to the file system. 174.It Bq Er EINVAL 175The 176.Fa flags 177value is invalid. 178.It Bq Er EINVAL 179The descriptor references a block or character device and the effective 180user ID is not the superuser. 181.El 182.Pp 183.Fn fchflags 184will fail if: 185.Bl -tag -width Er 186.It Bq Er EBADF 187The descriptor is not valid. 188.It Bq Er EINVAL 189.Fa fd 190refers to a socket, not to a file. 191.It Bq Er EINVAL 192The descriptor references a block or character device and the effective 193user ID is not the superuser. 194.It Bq Er EINVAL 195The 196.Fa flags 197value is invalid. 198.It Bq Er EPERM 199The effective user ID does not match the owner of the file and 200the effective user ID is not the superuser, or the effective user ID 201is not the superuser and at least one of the super-user-only flags 202for the named file would be changed. 203.It Bq Er EOPNOTSUPP 204The named file resides on a file system that does not support file 205flags. 206.It Bq Er EROFS 207The file resides on a read-only file system. 208.It Bq Er EIO 209An I/O error occurred while reading from or writing to the file system. 210.El 211.Sh SEE ALSO 212.Xr chflags 1 , 213.Xr init 8 214.Sh HISTORY 215The 216.Fn chflags 217and 218.Fn fchflags 219functions first appeared in 220.Bx 4.3 Reno . 221The 222.Fn chflagsat 223function first appeared in 224.Fx 10.0 . 225It was added to 226.Ox 227in 228.Ox 5.7 . 229