User Commands setfacl(1)
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_file file
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.
When the setfacl command is used, it may result in changes
to the file permission bits. When the user ACL entry for
the file owner is changed, the file owner class permission
bits will be modified. When the group ACL entry for the
file group class is changed, the file group class permission
bits will be modified. When the other ACL entry is changed,
the file other class permission bits will be modified.
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 per-
missions. 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
symbolic characters rwx or a number (the
same permissions 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. Notice 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:
-d acl_entries Deletes 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. Notice that deleting an entry
does not necessarily have the same effect as
removing all permissions from the entry.
-f acl_file Seta a file's ACL with the ACL entries con-
tained 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. Notice that if the acl_file has
been created as the output of the getfacl(1)
command, any effective permissions, which
will follow a "#", will be ignored.
-m acl_entries Adds one or more new ACL entries to the
file, and/or modifies 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 specified uid or gid, an entry
will be created. When using the -m option to
modify a default ACL, you must specify a
complete default ACL (user, group, other,
mask, and any additional entries) the first
time.
-r Recalculates the permissions for the ACL
mask entry. The permissions specified in the
ACL mask entry are ignored and replaced by
the maximum permissions necessary 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.
-s acl_entries Sets a file's ACL. All old ACL entries are
removed and replaced with the newly speci-
fied 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 additional default group entries speci-
fied, but there may not be duplicate addi-
tional default user entries with the same
uid, or duplicate default group entries with
the same gid.
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 access only, and others no access.
setfacl -s user:shea:rwx,user::rwx,group::rw-,mask:r--,other:--- abc
Notice 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 permission. The mask entry also specifies the max-
imum 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 per-
mission. 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
chmod(1), getfacl(1), umask(1), aclcheck(3SEC),
aclsort(3SEC), group(4), passwd(4), attributes(5)
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