.\"	$OpenBSD: changelist.5,v 1.6 2010/09/25 19:39:23 jmc Exp $
.\"
.\" Copyright (c) 2003 Jason McIntyre <jmc@openbsd.org>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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.Dd $Mdocdate: September 25 2010 $
.Dt CHANGELIST 5
.Os
.Sh NAME
.Nm changelist
.Nd list of backup files
.Sh SYNOPSIS
.Nm /etc/changelist
.Sh DESCRIPTION
The
.Pa /etc/changelist
file is a simple text file containing the names of files to be backed up
and checked for modification by the system security script,
.Xr security 8 .
It is checked daily by the
.Pa /etc/daily
script.
See
.Xr daily 8
for further details.
.Pp
Each line of the file contains the name of a file,
specified by its absolute pathname,
one per line.
By default, configuration files in
.Pa /etc ,
.Pa /root ,
and
.Pa /var
are added during system install.
Administrators may add additional files at their discretion.
Shell globbing is supported in pathnames.
.Pp
Backup files are held in the directory
.Pa /var/backups .
A backup of the current version of a file is kept in this directory, marked
.Qq current .
When the file is altered, the old version is marked as
.Qq backup
and the new version becomes
.Qq current .
.Pp
For example,
the system shell database,
.Pa /etc/shells ,
is held as
.Pa /var/backups/etc_shells.current .
When this file is modified, it is renamed to
.Pa /var/backups/etc_shells.backup
and the new version becomes
.Pa /var/backups/etc_shells.current .
Thereafter, these files are rotated.
.Pp
Diffs are mailed to the root administrator, in unified
.Xr diff 1
format, via
.Xr daily 8 ,
in the following format:
.Bd -unfilled -offset indent
=====
/etc/shells diffs (-OLD  +NEW)
=====
.Ed
.Pp
Files in
.Pa /etc/changelist
beginning with a
.Sq +
character
.Pq generally non-text files
are stored as
.Xr md5 1
checksums.
Results are mailed in the following format:
.Bd -unfilled -offset indent
======
/etc/ssh/ssh_host_key MD5 checksums
======
OLD:
NEW:
.Ed
.Pp
Lines beginning with the comment character
.Pq Sq # ,
blank lines,
and non-existent files are all silently ignored.
.\" .Sh ENVIRONMENT
.Sh FILES
.Bl -tag -width /etc/changelist -compact
.It Pa /etc/changelist
Default changelist.
.It Pa /etc/daily
Maintenance script which runs
.Xr security 8 .
.It Pa /etc/security
Shell script which reads
.Pa /etc/changelist .
.It Pa /var/backups/
Directory containing file backups.
.El
.Sh SEE ALSO
.Xr diff 1 ,
.Xr md5 1 ,
.Xr daily 8 ,
.Xr security 8
.Sh HISTORY
The
.Nm
manual page first appeared in
.Ox 3.5 .
.Sh CAVEATS
Anyone with the privileges to alter system configuration files
could also alter the backup files in
.Pa /var/backups .
It is important that this directory be owned by root:wheel
and have permissions 0700 set.
.Pp
Removal of the
.Pa /etc/changelist
file itself could cause confusion.
.Pp
.Nm
cannot warn about files being added to the system, although
.Xr security 8
will pick up on any files listed in
.Pa /etc/changelist
being added or deleted.
Removals are only noticed for files listed explicitly,
but not for files matched by globbing.
.Pp
If you hose your system configuration files,
you just might be able to find the information you need in
.Pa /var/backups .
This is not a CAVEAT, but we had to let you know somehow!