CHFLAGS(1) BSD General Commands Manual CHFLAGS(1)NAMEchflags — change file flags
SYNOPSISchflags [-fhv] [-R [-H | -L | -P]] flags file ...
DESCRIPTION
The chflags utility modifies the file flags of the listed files as speci‐
fied by the flags operand.
The options are as follows:
-f Do not display a diagnostic message if chflags could not modify
the flags for file, nor modify the exit status to reflect such
failures.
-H If the -R option is specified, symbolic links on the command line
are followed. (Symbolic links encountered in the tree traversal
are not followed.)
-h If the file is a symbolic link, change the file flags of the link
itself rather than the file to which it points.
-L If the -R option is specified, all symbolic links are followed.
-P If the -R option is specified, no symbolic links are followed.
This is the default.
-R Change the file flags for the file hierarchies rooted in the
files instead of just the files themselves.
-v Cause chflags to be verbose, showing filenames as the flags are
modified. If the -v option is specified more than once, the old
and new flags of the file will also be printed, in octal nota‐
tion.
The flags are specified as an octal number or a comma separated list of
keywords. The following keywords are currently defined:
arch, archived
set the archived flag (super-user only)
opaque set the opaque flag (owner or super-user only)
nodump set the nodump flag (owner or super-user only)
noshistory set the system nohistory flag (super-user only)
nouhistory, nohistory
set the user nohistory flag (owner or super-user only)
sappnd, sappend
set the system append-only flag (super-user only)
schg, schange, simmutable
set the system immutable flag (super-user only)
sunlnk, sunlink
set the system undeletable flag (super-user only)
uappnd, uappend
set the user append-only flag (owner or super-user
only)
uchg, uchange, uimmutable
set the user immutable flag (owner or super-user only)
uunlnk, uunlink
set the user undeletable flag (owner or super-user
only)
cache, ucache
control the data swapcache(8) (recursive, does not
cross mounts) (owner or super-user only)
noscache control the data swapcache(8) (recursive, does not
cross mounts) (super-user only)
If a “no” prefix is added or removed from a keyword, the meaning is
negated. For example:
nouchg clear the user immutable flag (owner or super-user only)
dump clear the nodump flag (owner or super-user only)
A few of the octal values include:
0 Clear all file flags.
1 Translates to the nodump keyword.
2 Translates to the uchg keyword.
3 Translates to the uchg, nodump keywords.
4 Translates to the uappnd keyword.
10 Translates to the opaque keyword.
20 translates to the uunlnk keyword.
Other combinations of keywords may be placed by using the octets
assigned; however, these are the most notable.
Unless the -H, -L, or -h options are given, chflags on a symbolic link
always succeeds and has no effect. The -H, -L and -P options are ignored
unless the -R option is specified. In addition, these options override
each other and the command's actions are determined by the last one spec‐
ified.
You can use “ls -lo” to see the flags of existing files.
Note that the ability to change certain flags is dependent on the current
kernel securelevel setting. See security(7) for more information on this
setting.
SWAPCACHE FLAGS
The cache bit may be set to enable swapcache(8) data caching. The supe‐
ruser flag, noscache may be used to disable swapcache(8) data caching and
overrides the user flag.
The flag is recursive but does not cross mount points. Setting it on a
top-level directories or mount point will automatically apply the flag to
the entire subtree or until a mount point is hit. You may have to
refresh the namecache with a dummy find(1) command after changing the
flag in a top level directory. You do not have to recursive set the flag
with chflags-R and, in fact, we do not recommend it under any circum‐
stances. Filesystems which do not support flags generally have a cache
mount option to enable swapcache operation on the mount.
If you intend to use swapcache data the vm.swapcache.use_chflags sysctl
determines whether the chflags flags are used or not. If turned off and
vm.swapcache.data_enable is turned on, data caching is turned on globally
and the file flags are ignored. If use_chflags is turned on along with
data_enable then only subtrees marked cacheable will be swapcached.
You would typically want to enable the cache on /usr, /home, and /bin and
disable it for /usr/obj. Alternatively if you want to cache NFS mounts
(where chflags doesn't work), you can set the flag on some parent direc‐
tory, possibly even the root (/) itself, and then selectively disable it
in places where you don't want it.
This only applies to data caching. Meta-data caching is universal when
enabled.
EXIT STATUS
The chflags utility exits 0 on success, and >0 if an error occurs.
SEE ALSOls(1), chflags(2), stat(2), fts(3), security(7), symlink(7), swapcache(8)HISTORY
The chflags command first appeared in 4.4BSD.
BUGS
Only a limited number of utilities are chflags aware. Some of these
tools include ls(1), cp(1), find(1), install(1), dump(8), and restore(8).
In particular a tool which is not currently chflags aware is the pax(1)
utility.
BSD November 11, 2008 BSD
