setfacl
NAME
setfacl - modify the Access Control List (ACL) for a file or
files
SYNOPSIS
setfacl [ -r ] -s acl_entries file
setfacl [ -r ] -md acl_entries file
setfacl [ -r ] -f acl_filefile
DESCRIPTION
For each file specified, setfacl will either replace its
entire ACL, including the default ACL on a directory, or it
will add, modify, or delete one or more ACL entries, includ-
ing default entries on directories.
Setting an ACL on a file also modifies the file's permission
bits. The user entry modifies the file owner permission
bits. If you don't specify a mask entry, the group entry
modifies the file group owner permission bits. If you
specify a mask entry, the file group owner permission bits
are modified based on the intersection (bitwise AND) of the
group and mask entries. The other entry modifies the other
permission bits.
If you use the chmod(1) command to change the file group
owner permissions on a file with ACL entries, both the file
group owner permissions and the ACL mask are changed to the
new permissions. Be aware that the new ACL mask permissions
may change the effective permissions for additional users
and groups who have ACL entries on the file.
A directory may contain default ACL entries. If a file or
directory is created in a directory that contains default
ACL entries, the newly created file will have permissions
generated according to the intersection of the default ACL
entries and the permissions requested at creation time. The
umask(1) will not be applied if the directory contains
default ACL entries. If a default ACL is specified for a
specific user (or users), the file will have a regular ACL
created; otherwise, only the mode bits will be initialized
according to the intersection described above. The default
ACL should be thought of as the maximum discretionary access
permissions that may be granted.
acl_entries Syntax
For the -m and -s options, acl_entries are one or more
comma-separated ACL entries.
An ACL entry consists of the following fields separated by
colons:
entry_type
Type of ACL entry on which to set file permis-
sions. For example, entry_type can be user (the
owner of a file) or mask (the ACL mask).
uid or gid
User name or user identification number. Or,
group name or group identification number.
perms Represents the permissions that are set on
entry_type. perms can be indicated by the sym-
bolic characters rwx or a number (the same per-
missions numbers used with the chmod command).
The following table shows the valid ACL entries (default
entries may only be specified for directories):
ACL Entry Description
u[ser]::perms File owner permissions.
g[roup]::perms File group owner permissions.
o[ther]:perms Permissions for users other than
the file owner or members of file
group owner.
m[ask]:perms The ACL mask. The mask entry indi-
cates the maximum permissions
allowed for users (other than the
owner) and for groups. The mask is
a quick way to change permissions
on all the users and groups.
u[ser]:uid:perms Permissions for a specific user.
For uid, you can specify either a
user name or a numeric UID.
g[roup]:gid:perms Permissions for a specific group.
For gid, you can specify either a
group name or a numeric GID.
d[efault]:u[ser]::perms Default file owner permissions.
d[efault]:g[roup]::perms Default file group owner permis-
sions.
d[efault]:o[ther]:perms Default permissions for users other
than the file owner or members of
the file group owner.
d[efault]:m[ask]:perms Default ACL mask.
d[efault]:u[ser]:uid:perms Default permissions for a specific
user. For uid, you can specify
either a user name or a numeric
UID.
d[efault]:g[roup]:gid:perms Default permissions for a specific
group. For gid, you can specify
either a group name or a numeric
GID.
For the -d option, acl_entries are one or more comma-
separated ACL entries without permissions. Note that the
entries for file owner, file group owner, ACL mask, and oth-
ers may not be deleted.
OPTIONS
The options have the following meaning:
-s acl_entries
Set a file's ACL. All old ACL entries are removed and
replaced with the newly specified ACL. The entries
need not be in any specific order. They will be sorted
by the command before being applied to the file.
Required entries:
o Exactly one user entry specified for the file
owner.
o Exactly one group entry for the file group
owner.
o Exactly one other entry specified.
If there are additional user and group entries:
o Exactly one mask entry specified for the ACL
mask that indicates the maximum permissions
allowed for users (other than the owner) and
groups.
o Must not be duplicate user entries with the same
uid.
o Must not be duplicate group entries with the
same gid.
If file is a directory, the following default ACL entries
may be specified:
o Exactly one default user entry for the file
owner.
o Exactly one default group entry for the file
group owner.
o Exactly one default mask entry for the ACL mask.
o Exactly one default other entry.
There may be additional default user entries and addi-
tional default group entries specified, but there may
not be duplicate additional default user entries with
the same uid, or duplicate default group entries with
the same gid.
-m acl_entries
Add one or more new ACL entries to the file, and/or
modify one or more existing ACL entries on the file.
If an entry already exists for a specified uid or gid,
the specified permissions will replace the current
permissions. If an entry does not exist for the speci-
fied uid or gid, an entry will be created.
-d acl_entries
Delete one or more entries from the file. The entries
for the file owner, the file group owner, and others
may not be deleted from the ACL. Note that deleting an
entry does not necessarily have the same effect as
removing all permissions from the entry.
-f acl_file
Set a file's ACL with the ACL entries contained in the
file named acl_file. The same constraints on specified
entries hold as with the -s option. The entries are
not required to be in any specific order in the file.
Also, if you specify a dash '-' for acl_file, standard
input is used to set the file's ACL.
The character "#" in acl_file may be used to indicate
a comment. All characters, starting with the "#" until
the end of the line, will be ignored. Note that if the
acl_file has been created as the output of the get-
facl(1) command, any effective permissions, which will
follow a "#", will be ignored.
-r Recalculate the permissions for the ACL mask entry.
The permissions specified in the ACL mask entry are
ignored and replaced by the maximum permissions neces-
sary to grant the access to all additional user, file
group owner, and additional group entries in the ACL.
The permissions in the additional user, file group
owner, and additional group entries are left
unchanged.
EXAMPLES
Example 1: Adding read permission only
The following example adds one ACL entry to file abc, which
gives user shea read permission only.
setfacl -m user:shea:r-- abc
Example 2: Replacing a file's entire ACL
The following example replaces the entire ACL for the file
abc, which gives shea read access, the file owner all
access, the file group owner read access only, the ACL mask
read/write access, and others no access.
setfacl -s user:shea:rwx,user::rwx,group::rw-,mask:r--,other:--- abc
Note that after this command, the file permission bits are
rwxr-----. Even though the file group owner was set with
read/write permissions, the ACL mask entry limits it to have
only read permissions. The mask entry also specifies the
maximum permissions available to all additional user and
group ACL entries. Once again, even though the user shea was
set with all access, the mask limits it to have only read
permissions. The ACL mask entry is a quick way to limit or
open access to all the user and group entries in an ACL. For
example, by changing the mask entry to read/write, both the
file group owner and user shea would be given read/write
access.
Example 3: Setting the same ACL on two files
The following example sets the same ACL on file abc as the
file xyz.
getfacl xyz | setfacl -f - abc
FILES
/etc/passwd
password file
/etc/group
group file
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcsu |
|_____________________________|_____________________________|
SEE ALSO
getfacl(1), umask(1), aclcheck(3SEC), aclsort(3SEC),
group(4), passwd(4), attributes(5), chmod(1)
Man(1) output converted with
man2html