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CHFLAGS(2)		    BSD	System Calls Manual		    CHFLAGS(2)

NAME
     chflags, lchflags,	fchflags, chflagsat -- set file	flags

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <sys/stat.h>
     #include <unistd.h>

     int
     chflags(const char	*path, unsigned	long flags);

     int
     lchflags(const char *path,	unsigned long flags);

     int
     fchflags(int fd, unsigned long flags);

     int
     chflagsat(int fd, const char *path, unsigned long flags, int atflag);

DESCRIPTION
     The file whose name is given by path or referenced	by the descriptor fd
     has its flags changed to flags.

     The lchflags() system call	is like	chflags() except in the	case where the
     named file	is a symbolic link, in which case lchflags() will change the
     flags of the link itself, rather than the file it points to.

     The chflagsat() is	equivalent to either chflags() or lchflags() depending
     on	the atflag except in the case where path specifies a relative path.
     In	this case the file to be changed is determined relative	to the direc-
     tory associated with the file descriptor fd instead of the	current	work-
     ing directory.  The values	for the	atflag are constructed by a bitwise-
     inclusive OR of flags from	the following list, defined in <fcntl.h>:

     AT_SYMLINK_NOFOLLOW
	     If	path names a symbolic link, then the flags of the symbolic
	     link are changed.

     If	chflagsat() is passed the special value	AT_FDCWD in the	fd parameter,
     the current working directory is used.  If	also atflag is zero, the be-
     havior is identical to a call to chflags().

     The flags specified are formed by or'ing the following values

	   SF_APPEND	 The file may only be appended to.
	   SF_ARCHIVED	 The file has been archived.  This flag	means the op-
			 posite	of the DOS, Windows and	CIFS FILE_ATTRI-
			 BUTE_ARCHIVE attribute.  This flag has	been depre-
			 cated,	and may	be removed in a	future release.
	   SF_IMMUTABLE	 The file may not be changed.
	   SF_NOUNLINK	 The file may not be renamed or	deleted.
	   SF_SNAPSHOT	 The file is a snapshot	file.
	   UF_APPEND	 The file may only be appended to.
	   UF_ARCHIVE	 The file needs	to be archived.	 This flag has the
			 same meaning as the DOS, Windows and CIFS FILE_ATTRI-
			 BUTE_ARCHIVE attribute.  Filesystems in FreeBSD may
			 or may	not have special handling for this flag.  For
			 instance, ZFS tracks changes to files and will	set
			 this bit when a file is updated.  UFS only stores the
			 flag, and relies on the application to	change it when
			 needed.
	   UF_HIDDEN	 The file may be hidden	from directory listings	at the
			 application's discretion.  The	file has the DOS, Win-
			 dows and CIFS FILE_ATTRIBUTE_HIDDEN attribute.
	   UF_IMMUTABLE	 The file may not be changed.
	   UF_NODUMP	 Do not	dump the file.
	   UF_NOUNLINK	 The file may not be renamed or	deleted.
	   UF_OFFLINE	 The file is offline, or has the Windows and CIFS
			 FILE_ATTRIBUTE_OFFLINE	attribute.  Filesystems	in
			 FreeBSD store and display this	flag, but do not pro-
			 vide any special handling when	it is set.
	   UF_OPAQUE	 The directory is opaque when viewed through a union
			 stack.
	   UF_READONLY	 The file is read only,	and may	not be written or ap-
			 pended.  Filesystems may use this flag	to maintain
			 compatibility with the	DOS, Windows and CIFS FILE_AT-
			 TRIBUTE_READONLY attribute.
	   UF_REPARSE	 The file contains a Windows reparse point and has the
			 Windows and CIFS FILE_ATTRIBUTE_REPARSE_POINT attri-
			 bute.
	   UF_SPARSE	 The file has the Windows FILE_ATTRIBUTE_SPARSE_FILE
			 attribute.  This may also be used by a	filesystem to
			 indicate a sparse file.
	   UF_SYSTEM	 The file has the DOS, Windows and CIFS	FILE_ATTRI-
			 BUTE_SYSTEM attribute.	 Filesystems in	FreeBSD	may
			 store and display this	flag, but do not provide any
			 special handling when it is set.

     If	one of SF_IMMUTABLE, SF_APPEND,	or SF_NOUNLINK is set a	non-super-user
     cannot change any flags and even the super-user can change	flags only if
     securelevel is 0.	(See init(8) for details.)

     The UF_IMMUTABLE, UF_APPEND, UF_NOUNLINK, UF_NODUMP, and UF_OPAQUE	flags
     may be set	or unset by either the owner of	a file or the super-user.

     The SF_IMMUTABLE, SF_APPEND, SF_NOUNLINK, and SF_ARCHIVED flags may only
     be	set or unset by	the super-user.	 Attempts to toggle these flags	by
     non-super-users are rejected.  These flags	may be set at any time,	but
     normally may only be unset	when the system	is in single-user mode.	 (See
     init(8) for details.)

     The implementation	of all flags is	filesystem-dependent.  See the de-
     scription of the UF_ARCHIVE flag above for	one example of the differences
     in	behavior.  Care	should be exercised when writing applications to ac-
     count for support or lack of support of these flags in various filesys-
     tems.

     The SF_SNAPSHOT flag is maintained	by the system and cannot be toggled.

RETURN VALUES
     Upon successful completion, the value 0 is	returned; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the
     error.

ERRORS
     The chflags() system call will fail if:

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or
			an entire path name exceeded 1023 characters.

     [ENOENT]		The named file does not	exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EPERM]		The effective user ID does not match the owner of the
			file and the effective user ID is not the super-user.

     [EPERM]		One of SF_IMMUTABLE, SF_APPEND,	or SF_NOUNLINK is set
			and the	user is	either not the super-user or se-
			curelevel is greater than 0.

     [EPERM]		A non-super-user attempted to toggle one of
			SF_ARCHIVED, SF_IMMUTABLE, SF_APPEND, or SF_NOUNLINK.

     [EPERM]		An attempt was made to toggle the SF_SNAPSHOT flag.

     [EROFS]		The named file resides on a read-only file system.

     [EFAULT]		The path argument points outside the process's allo-
			cated address space.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     [EOPNOTSUPP]	The underlying file system does	not support file
			flags, or does not support all of the flags set	in
			flags.

     The fchflags() system call	will fail if:

     [EBADF]		The descriptor is not valid.

     [EINVAL]		The fd argument	refers to a socket, not	to a file.

     [EPERM]		The effective user ID does not match the owner of the
			file and the effective user ID is not the super-user.

     [EPERM]		One of SF_IMMUTABLE, SF_APPEND,	or SF_NOUNLINK is set
			and the	user is	either not the super-user or se-
			curelevel is greater than 0.

     [EPERM]		A non-super-user attempted to toggle one of
			SF_ARCHIVED, SF_IMMUTABLE, SF_APPEND, or SF_NOUNLINK.

     [EPERM]		An attempt was made to toggle the SF_SNAPSHOT flag.

     [EROFS]		The file resides on a read-only	file system.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     [EOPNOTSUPP]	The underlying file system does	not support file
			flags, or does not support all of the flags set	in
			flags.

SEE ALSO
     chflags(1), fflagstostr(3), strtofflags(3), init(8), mount_unionfs(8)

HISTORY
     The chflags() and fchflags() system calls first appeared in 4.4BSD.  The
     lchflags()	system call first appeared in FreeBSD 5.0.  The	chflagsat()
     system call first appeared	in FreeBSD 10.0.

BSD				March 22, 2013				   BSD
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY

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