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.Dd February 20, 2014
.Dt NFS4MAPID 8
.Os 
.Sh NAME
.Nm nfs4mapid
.Nd shows NFSv4 mappings from uids or gids to
over the wire string names and string names to uids or gids.
.Sh SYNOPSIS
.Nm nfs4mapid
.Op Fl G 
.Ar string name
.Nm nfs4mapid
.Op Fl G
.Ar GUID
.Nm nfs4mapid
.Fl u Ar uid
.Nm nfs4mapid
.Fl g Ar gid
.Sh DESCRIPTION
In the first form,
.Nm nfs4mapid
shows translations from
.Tn NFSv4
string representations of users, and with the 
.Fl G
option, groups, to the corresponding local uids and gids.
In the second form shows the translations from
.Tn opendirectoy
GUIDS to
.Tn NFSv4
strings. The well known strings names (which are distinguished by a trailing 
.Sq @
), such as
.Qq OWNER@
and
.Qq GROUP@
are represented locally by GUIDs and may not map to uids
or gids. To map those GUIDS to
.Tn NFSv4
strings use this form. The first form can be used to map the well
known ids to GUIDs.
.Nm nfs4mapid
does this by looking at the trailing 
.Sq @
sign. Note that
.Tn NFSv4
well known names are always groups and are used in ACEs.
In the third form, it shows the mapping from uids to the
.Tn NFSv4
user@domain form.
Similarly, in the last form it shows the mapping from gids to
the
.Tn NFSv4
group@domain.
.Nm nfs4mapid
will also show the intermediate GUID translation if used. The 
.Tn NFSv4
domain name should be set with
.Xr dscl 1 .
See
.Xr opendirectory 8 
for instructions.
.Bl -tag -width Ds
.It Fl G
Map an
.Tn NFSv4
string to a gid.
.It Fl u
Map a uid to an
.Tn NFSv4
user@domain string.
.It Fl g
Map a gid to an
.Tn NFSv4
group@domain string.
.El
.Sh NOTES
.Nm
uses a privileged nfs client system call to pass the translation request down to the kernel, so results will be the same as a request coming from an NFSv4 server. Because of this,
.Nm
must be run with root privileges.
.Sh SEE ALSO
.Xr dscl 1 ,
.Xr nfs 5 ,
.Xr opendirectoryd 8 ,
.Xr mount_nfs 8 ,
.Sh HISTORY
The
.Nm
utility first appeared in OSX 10.10