.TH HGFS 4
.SH NAME
hgfs \- mercurial file system
.SH SYNOPSIS
.B hgfs
[
.B -D
]
[
.B -m
.I mtpt
]
[
.B -s
.I service
]
[
.I dir
]
.SH DESCRIPTION
Mercurial is a distributed version control system. It tracks
and organizes files and keeps a change history of them. The
file revisions are stored as packed deltas in a repository
that can be checked out with the
.IR hg (1)
program.

.I Hgfs
serves a mercurial repository as a read only filesystem where
each file revision and its metadata is accessible as files.

The repository can be specified by passing the working directory
.I dir
as the last argument. When omited, hgfs locates the repository by waking
upwards from the current working directory until the
.B .hg
sub-directory is found. If no
.I mtpt
was specified with
.B -m
, then hgfs will mount itself on
.B /n/hg
(default). When a
.I service
name is given with the
.B -s
flag, then the 9p service pipe 
.B /srv/\fIservice\fR
is created and can be mounted from another namespace.
The
.B -D
flag enables 9p debug messages.

The root of the served filesystem contains directories each 
corresponding to a specific changeset revision in the
repository.

The revision directories are named by ther revision id wich
has the form [\fId\fB.\fR]\fIhhhhhhhhhhhh\fR where
.I d
is the decimal revision number starting from 0 and
.I hhhhhhhhhhhh
is the hexadecimal hash prefix of the changeset. As both,
the revision number
.I d
and the hash prefix
.I hhhhhhhhhhhh
are able to identify
a revision uniquely, only one of them needs to be given
when walking the root directory. The hexadecimal hash
can be shortend as long as the resulting lookup yields
a uniqueue result. The special name
.B tip
corresponds to the latest revision but is not listed.

In each revision directory the following files can be found:
.TP
.B rev1
contains the parent revision id as text.
.TP
.B rev2
If the changeset was a merge, contains the other parent revision id. Otherwise, a zero size file.
.TP
.B log
The
.B log
file contains a list of file names, separated by a newline, that where
affected in this changeset. Files that are listed in the log
but are not accessible in
.B files
or
.B changes
directories have been deleted in this changeset.
.TP
.B who
committer of the changeset.
.TP
.B why
commit message of the changeset.
.TP
.B files
A directory that contains a snapshot of the tree at the time
the changeset was commited.

To retrieve the \fIn\fRth
past version of a file relative to the changeset,
one can append \fB.\fIn\fR
to the filename. Appending \fB.rev\fIn\fR yields
a file that contains its revision id as text. Note that
appending \fB.rev\fI0\fR or \fB.rev\fR yields the file containing the
revision id of the changeset when the file was last modified
and \fB.\fI0\fR yields the same file as when omiting the appendix.
.TP
.B changes
Same as
.B files,
but contains only the changed files of the changeset.
.SH SEE ALSO
.IR hg (1)