CHACL(1) Access Control Lists CHACL(1)
chacl – change the access control list of a file or directory
chacl acl pathname…
chacl -b acl dacl pathname…
chacl -d dacl pathname…
chacl -R pathname…
chacl -D pathname…
chacl -B pathname…
chacl -l pathname…
chacl -r pathname…
chacl is an IRIX-compatibility command, and is maintained for those
users who are familiar with its use from either XFS or IRIX. Refer to
the SEE ALSO section below for a description of tools which conform
more closely to the (withdrawn draft) POSIX 1003.1e standard which
describes Access Control Lists (ACLs).
chacl changes the ACL(s) for a file or directory. The ACL(s) specified
are applied to each file in the pathname arguments.
Each ACL is a string which is interpreted using the acl_from_text(3)
routine. These strings are made up of comma separated clauses each of
which is of the form, tag:name:perm. Where tag can be:
“user” (or “u”)
indicating that the entry is a user ACL entry.
“group” (or “g”)
indicating that the entry is a group ACL entry.
“other” (or “o”)
indicating that the entry is an other ACL entry.
“mask” (or “m”)
indicating that the entry is a mask ACL entry.
name is a string which is the user or group name for the ACL entry. A
null name in a user or group ACL entry indicates the file’s owner or
file’s group. perm is the string “rwx” where each of the entries may
be replaced by a “-” indicating no access of that type, e.g. “r-x”,
-b Indicates that there are two ACLs to change, the first is the
file access ACL and the second the directory default ACL.
-d Used to set only the default ACL of a directory.
-R Removes the file access ACL only.
-D Removes directory default ACL only.
-B Remove all ACLs.
-l Lists the access ACL and possibly the default ACL associated
with the specified files or directories. This option was added
during the Linux port of XFS, and is not IRIX compatible.
-r Set the access ACL recursively for each subtree rooted at path‐
name(s). This option was also added during the Linux port of
XFS, and is not compatible with IRIX.
A minimum ACL:
chacl u::rwx,g::r-x,o::r– file
The file ACL is set so that the file’s owner has “rwx”, the file’s
group has read and execute, and others have read only access to the
An ACL that is not a minimum ACL, that is, one that specifies a user or
group other than the file’s owner or owner’s group, must contain a mask
chacl u::rwx,g::r-x,o::r–,u:bob:r–,m::r-x file1 file2
To set the default and access ACLs on newdir to be the same as on old‐
dir, you could type:
chacl -b `chacl -l olddir | \
sed -e ‘s/.*\[//’ -e ‘s#/# #’ -e ‘s/]$//’` newdir
chacl can replace the existing ACL. To add or delete entries, you must
first do chacl -l to get the existing ACL, and use the output to form
the arguments to chacl.
Changing the permission bits of a file will change the file access ACL
settings (see chmod(1)). However, file creation mode masks (see
umask(1)) will not affect the access ACL settings of files created
using directory default ACLs.
ACLs are filesystem extended attributes and hence are not typically
archived or restored using the conventional archiving utilities. See
attr(5) for more information about extended attributes and see xfs‐
dump(8) for a method of backing them up under XFS.
getfacl(1), setfacl(1), chmod(1), umask(1), acl_from_text(3), acl(5),
September 2001 ACL File Utilities CHACL(1)