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 Oct 29, 2010 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 set these flags by non-super-users are rejected, attempts by 118non-superusers to clear flags that are already unset are silently ignored. 119These flags may be set at any time, but normally may only be unset when 120the system is in single-user mode. 121(See 122.Xr init 8 123for details.) 124.Pp 125The 126.Dv SF_SNAPSHOT 127flag is maintained by the system and cannot be changed by any user. 128.Sh RETURN VALUES 129.Rv -std 130.Sh ERRORS 131The 132.Fn chflags 133system call will fail if: 134.Bl -tag -width Er 135.It Bq Er ENOTDIR 136A component of the path prefix is not a directory. 137.It Bq Er ENAMETOOLONG 138A component of a pathname exceeded 255 characters, 139or an entire path name exceeded 1023 characters. 140.It Bq Er ENOENT 141The named file does not exist. 142.It Bq Er EACCES 143Search permission is denied for a component of the path prefix. 144.It Bq Er ELOOP 145Too many symbolic links were encountered in translating the pathname. 146.It Bq Er EPERM 147The effective user ID does not match the owner of the file and 148the effective user ID is not the super-user. 149.It Bq Er EPERM 150One of 151.Dv SF_IMMUTABLE , SF_APPEND , 152or 153.Dv SF_NOUNLINK 154is set and the user is either not the super-user or 155securelevel is greater than 0. 156.It Bq Er EPERM 157A non-super-user tries to set one of 158.Dv SF_ARCHIVED , SF_IMMUTABLE , SF_APPEND , 159or 160.Dv SF_NOUNLINK . 161.It Bq Er EPERM 162User tries to set or remove the 163.Dv SF_SNAPSHOT 164flag. 165.It Bq Er EROFS 166The named file resides on a read-only file system. 167.It Bq Er EFAULT 168The 169.Fa path 170argument 171points outside the process's allocated address space. 172.It Bq Er EIO 173An 174.Tn I/O 175error occurred while reading from or writing to the file system. 176.It Bq Er EOPNOTSUPP 177The underlying file system does not support file flags. 178.El 179.Pp 180The 181.Fn fchflags 182system call will fail if: 183.Bl -tag -width Er 184.It Bq Er EBADF 185The descriptor is not valid. 186.It Bq Er EINVAL 187The 188.Fa fd 189argument 190refers to a socket, not to a file. 191.It Bq Er EPERM 192The effective user ID does not match the owner of the file and 193the effective user ID is not the super-user. 194.It Bq Er EPERM 195One of 196.Dv SF_IMMUTABLE , SF_APPEND , 197or 198.Dv SF_NOUNLINK 199is set and the user is either not the super-user or 200securelevel is greater than 0. 201.It Bq Er EPERM 202A non-super-user tries to set one of 203.Dv SF_ARCHIVED , SF_IMMUTABLE , SF_APPEND , 204or 205.Dv SF_NOUNLINK . 206.It Bq Er EPERM 207User tries to set or remove the 208.Dv SF_SNAPSHOT 209flag. 210.It Bq Er EROFS 211The file resides on a read-only file system. 212.It Bq Er EIO 213An 214.Tn I/O 215error occurred while reading from or writing to the file system. 216.It Bq Er EOPNOTSUPP 217The underlying file system does not support file flags. 218.El 219.Sh SEE ALSO 220.Xr chflags 1 , 221.Xr fflagstostr 3 , 222.Xr strtofflags 3 , 223.Xr init 8 , 224.Xr mount_unionfs 8 225.Sh HISTORY 226The 227.Fn chflags 228and 229.Fn fchflags 230system calls first appeared in 231.Bx 4.4 . 232