1.\" Copyright (c) 1989, 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.\" 4. 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.\" @(#)chflags.2 8.3 (Berkeley) 5/2/95 29.\" $FreeBSD$ 30.\" 31.Dd Apr 13, 2012 32.Dt CHFLAGS 2 33.Os 34.Sh NAME 35.Nm chflags , 36.Nm lchflags , 37.Nm fchflags 38.Nd set file flags 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In sys/stat.h 43.In unistd.h 44.Ft int 45.Fn chflags "const char *path" "u_long flags" 46.Ft int 47.Fn lchflags "const char *path" "int flags" 48.Ft int 49.Fn fchflags "int fd" "u_long flags" 50.Sh DESCRIPTION 51The file whose name 52is given by 53.Fa path 54or referenced by the descriptor 55.Fa fd 56has its flags changed to 57.Fa flags . 58.Pp 59The 60.Fn lchflags 61system call is like 62.Fn chflags 63except in the case where the named file is a symbolic link, 64in which case 65.Fn lchflags 66will change the flags of the link itself, 67rather than the file it points to. 68.Pp 69The flags specified are formed by 70.Em or Ns 'ing 71the following values 72.Pp 73.Bl -tag -width ".Dv SF_IMMUTABLE" -compact -offset indent 74.It Dv UF_NODUMP 75Do not dump the file. 76.It Dv UF_IMMUTABLE 77The file may not be changed. 78.It Dv UF_APPEND 79The file may only be appended to. 80.It Dv UF_NOUNLINK 81The file may not be renamed or deleted. 82.It Dv UF_OPAQUE 83The directory is opaque when viewed through a union stack. 84.It Dv SF_ARCHIVED 85The file may be archived. 86.It Dv SF_IMMUTABLE 87The file may not be changed. 88.It Dv SF_APPEND 89The file may only be appended to. 90.It Dv SF_NOUNLINK 91The file may not be renamed or deleted. 92.It Dv SF_SNAPSHOT 93The file is a snapshot file. 94.El 95.Pp 96If one of 97.Dv SF_IMMUTABLE , SF_APPEND , 98or 99.Dv SF_NOUNLINK 100is set a non-super-user cannot change any flags and even the super-user 101can change flags only if securelevel is greater than 0. 102(See 103.Xr init 8 104for details.) 105.Pp 106The 107.Dv UF_IMMUTABLE , UF_APPEND , UF_NOUNLINK , UF_NODUMP , 108and 109.Dv UF_OPAQUE 110flags may be set or unset by either the owner of a file or the super-user. 111.Pp 112The 113.Dv SF_IMMUTABLE , SF_APPEND , SF_NOUNLINK , 114and 115.Dv SF_ARCHIVED 116flags may only be set or unset by the super-user. 117Attempts to toggle these flags by non-super-users are rejected. 118These flags may be set at any time, but normally may only be unset when 119the system is in single-user mode. 120(See 121.Xr init 8 122for details.) 123.Pp 124The 125.Dv SF_SNAPSHOT 126flag is maintained by the system and cannot be toggled. 127.Sh RETURN VALUES 128.Rv -std 129.Sh ERRORS 130The 131.Fn chflags 132system call will fail if: 133.Bl -tag -width Er 134.It Bq Er ENOTDIR 135A component of the path prefix is not a directory. 136.It Bq Er ENAMETOOLONG 137A component of a pathname exceeded 255 characters, 138or an entire path name exceeded 1023 characters. 139.It Bq Er ENOENT 140The named file does not exist. 141.It Bq Er EACCES 142Search permission is denied for a component of the path prefix. 143.It Bq Er ELOOP 144Too many symbolic links were encountered in translating the pathname. 145.It Bq Er EPERM 146The effective user ID does not match the owner of the file and 147the effective user ID is not the super-user. 148.It Bq Er EPERM 149One of 150.Dv SF_IMMUTABLE , SF_APPEND , 151or 152.Dv SF_NOUNLINK 153is set and the user is either not the super-user or 154securelevel is greater than 0. 155.It Bq Er EPERM 156A non-super-user attempted to toggle one of 157.Dv SF_ARCHIVED , SF_IMMUTABLE , SF_APPEND , 158or 159.Dv SF_NOUNLINK . 160.It Bq Er EPERM 161An attempt was made to toggle the 162.Dv SF_SNAPSHOT 163flag. 164.It Bq Er EROFS 165The named file resides on a read-only file system. 166.It Bq Er EFAULT 167The 168.Fa path 169argument 170points outside the process's allocated address space. 171.It Bq Er EIO 172An 173.Tn I/O 174error occurred while reading from or writing to the file system. 175.It Bq Er EOPNOTSUPP 176The underlying file system does not support file flags, or 177does not support all of the flags set in 178.Fa flags . 179.El 180.Pp 181The 182.Fn fchflags 183system call will fail if: 184.Bl -tag -width Er 185.It Bq Er EBADF 186The descriptor is not valid. 187.It Bq Er EINVAL 188The 189.Fa fd 190argument 191refers to a socket, not to a file. 192.It Bq Er EPERM 193The effective user ID does not match the owner of the file and 194the effective user ID is not the super-user. 195.It Bq Er EPERM 196One of 197.Dv SF_IMMUTABLE , SF_APPEND , 198or 199.Dv SF_NOUNLINK 200is set and the user is either not the super-user or 201securelevel is greater than 0. 202.It Bq Er EPERM 203A non-super-user attempted to toggle one of 204.Dv SF_ARCHIVED , SF_IMMUTABLE , SF_APPEND , 205or 206.Dv SF_NOUNLINK . 207.It Bq Er EPERM 208An attempt was made to toggle the 209.Dv SF_SNAPSHOT 210flag. 211.It Bq Er EROFS 212The file resides on a read-only file system. 213.It Bq Er EIO 214An 215.Tn I/O 216error occurred while reading from or writing to the file system. 217.It Bq Er EOPNOTSUPP 218The underlying file system does not support file flags, or 219does not support all of the flags set in 220.Fa flags . 221.El 222.Sh SEE ALSO 223.Xr chflags 1 , 224.Xr fflagstostr 3 , 225.Xr strtofflags 3 , 226.Xr init 8 , 227.Xr mount_unionfs 8 228.Sh HISTORY 229The 230.Fn chflags 231and 232.Fn fchflags 233system calls first appeared in 234.Bx 4.4 . 235