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MERGEMASTER(8)		FreeBSD	System Manager's Manual		MERGEMASTER(8)

     mergemaster -- merge configuration	files, et al during an upgrade

     mergemaster [-scrvhpCP] [-a|iFU] [--run-updates=[always|never]]
		 [-m /path/to/sources] [-t /path/to/temp/root] [-d] [-u	N]
		 [-w N]	[-A Target architecture] [-D /destdir/path]

     The mergemaster utility is	deprecated and may not be available in
     FreeBSD 14.0 or later.  Users are advised to use etcupdate(8) instead.

     The mergemaster utility is	a Bourne shell script which is designed	to aid
     you in updating the various configuration and other files associated with
     FreeBSD.  It is HIGHLY recommended	that you back up your /etc directory
     before beginning this process.

     The script	uses /usr/src/Makefile to build	a temporary root environment
     from / down, populating that environment with the various files.  You can
     specify a different source	directory with the -m command line option, or
     specify the destination directory with the	-D option.  It then compares
     each file in that environment to its installed counterpart.  When the
     script finds a change in the new file, or there is	no installed version
     of	the new	file it	gives you four options to deal with it.	 You can in-
     stall the new file	as is, delete the new file, merge the old and new
     files (as appropriate) using sdiff(1) or leave the	file in	the temporary
     root environment to merge by hand later.

     By	default	it creates the temporary root in /var/tmp/temproot and com-
     pares the Version Control System (VCS) Id strings ($FreeBSD) for files
     that have them, deleting the temporary file if the	strings	match.	If
     there is no Id string, or if the strings are different it compares	the
     files themselves.	You can	also specify that the script ignore the	Id
     strings and compare every file with the -s	option.	 Using the -F option
     mergemaster will install the new file for you if they differ only by VCS

     The merge menu option is designed to let you easily combine your cus-
     tomizations from the old version of a file	into the new one.  While you
     can use the merge function	to incorporate changes from files that you
     have not customized, it is	not recommended.

     The mergemaster utility checks your umask and issues a warning for	any-
     thing other than 022.  While it is	not mandatory to grant world read per-
     missions for most configuration files, you	may run	into problems without
     them.  If you choose a umask other	than 022 and experience	trouble	later
     this could	be the cause.  /etc/master.passwd is treated as	a special
     case.  If you choose to install this file or a merged version of it the
     file permissions are always 600 (rw-------) for security reasons.	After
     installing	an updated version of this file	you should probably run
     pwd_mkdb(8) with the -p option to rebuild your password databases and
     recreate /etc/passwd.

     The script	uses the owner and group ids that the files are	created	with
     by	/usr/src/etc/Makefile, and file	permissions as specified by the	umask.
     Unified diffs are used by default to display any differences unless you
     choose context diffs.

     The mergemaster utility will source scripts that you specify right	before
     it	starts the comparison, and after it is done running.  The easiest way
     to	handle this is to place	the path to the	script(s) in the appropriate
     variables in your .mergemasterrc file.  The script	sourced	before compar-
     ison is named in MM_PRE_COMPARE_SCRIPT, and the one sourced after the
     script is done is MM_EXIT_SCRIPT.	This is	the recommended	way to specify
     local modifications, or files that	you want to give special handling to.
     This includes files that you want to be deleted without being compared.
     Because the named scripts are sourced from	within mergemaster, all	of the
     script's variables	are available for use in your custom script.  You can
     also use /etc/mergemaster.rc which	will be	read before .mergemasterrc.
     Options specified on the command line are updated last, and therefore can
     override both files.

     When the comparison is done if there are any files	remaining in the temp-
     root directory they will be listed, and if	the -a option is not in	use
     the user will be given the	option of deleting the temproot	directory.  If
     there are no files	remaining in the temproot directory it will be

     The options are as	follows:

     -s		 Perform a strict comparison, diffing every pair of files.
		 This comparison is performed line by line, without regard to
		 VCS Ids.

     -c		 Use context diffs instead of unified diffs.

     -r		 Re-run	mergemaster on a previously cleaned directory, skip-
		 ping the creation of the temporary root environment.  This
		 option	is compatible with all other options.

     -v		 Be more verbose about the process.  You should	probably use
		 this option the first time you	run mergemaster.  This option
		 also gives you	a list of files	that exist only	in the in-
		 stalled version of /etc.

     -a		 Run automatically.  This option will leave all	the files that
		 differ	from the installed versions in the temporary directory
		 to be dealt with by hand.  If the temproot directory exists,
		 it creates a new one in a previously non-existent directory.
		 This option unsets the	verbose	flag, and is not compatible
		 with -i, -F, or -U.  Setting -a makes -w superfluous.

     -h		 Display usage and help	information.

     -i		 Automatically install any files that do not exist in the des-
		 tination directory.

     -p		 Pre-buildworld	mode.  Compares	only files known to be essen-
		 tial to the success of	{build|install}world, i.e., /etc/group
		 and /etc/master.passwd.

     -F		 If the	files differ only by VCS Id ($FreeBSD) install the new

     -C		 After a standard mergemaster run, compares your rc.conf[.lo-
		 cal] options to the defaults.

     -P		 Preserve files	that you replace in
		 /var/tmp/mergemaster/preserved-files-_date_, or another di-
		 rectory you specify in	your mergemaster rc file.

     -U		 Attempt to auto upgrade files that have not been user modi-
		 fied.	This option can	be dangerous when there	are critical
		 changes in the	new versions that affect your running system.

		 Specify always	or never to run	newaliases, pwd_mkdb, etc.  at
		 the end of the	comparison run.	 If this option	is omitted the
		 default is to prompt the user for each	update as necessary.

     -m	/path/to/sources
		 Specify the path to the directory where you want to do	the
		 make(1).  (In other words, where your sources are, but	-s was
		 already taken.)  In older versions of mergemaster the path to
		 src/etc was required.	mergemaster will convert the path if
		 this older method is used.

     -t	/path/to/temp/root
		 Create	the temporary root environment in /path/to/temp/root
		 instead of the	default	/var/tmp/temproot.

     -d		 Add the date and time to the name of the temporary root di-
		 rectory.  If -t is specified, this option must	follow it if
		 you want the date added too.

     -u	N	 Specify a numeric umask.  The default is 022.

     -w	N	 Supply	an alternate screen width to the sdiff(1) command in
		 numbers of columns.  The default is 80.

     -A	Target architecture
		 Specify an alternative	TARGET_ARCH architecture name.

     -D	/path	 Specify the destination directory for the installed files.

     The mergemaster utility uses the PAGER environment	variable if set.  Oth-
     erwise it uses less(1).  If PAGER specifies a program outside its limited
     PATH without specifying the full path, mergemaster	prompts	you with op-
     tions on how to proceed.  The MM_PRE_COMPARE_SCRIPT and MM_EXIT_SCRIPT
     variables are used	as described above.  Other variables that are used by
     the script	internally can be specified in .mergemasterrc as described in
     more detail below.


     The mergemaster utility will . (source) these files if they exist.	 Com-
     mand line options will override rc	file options.  $HOME/.mergemasterrc
     overrides /etc/mergemaster.rc.  Here is an	example	with all values	com-
     mented out:

     # These are options for mergemaster, with their default values listed
     # The following options have command line overrides
     # The target architecture (-A, unset by default)
     # Sourcedir is the	directory to do	the 'make' in (-m)
     # Directory to install the	temporary root environment into	(-t)
     # Specify the destination directory for the installed files (-D)
     # Strict comparison skips the VCS Id test and compares every file (-s)
     # Type of diff, such as unified, context, etc. (-c)
     # Install the new file if it differs only by VCS Id ($FreeBSD, -F)
     # Verbose mode includes more details and additional checks	(-v)
     # Automatically install files that	do not exist on	the system already (-i)
     # Automatically upgrade files that	have not been user modified (-U)
     # ***DANGEROUS***
     # Either always or	never run newaliases, pwd_mkdb at the end (--run-updates)
     # Compare /etc/rc.conf[.local] to /etc/defaults/rc.conf (-C)
     # Preserve	files that you replace (-P)
     #PRESERVE_FILES_DIR=/var/tmp/mergemaster/preserved-files-`date +%y%m%d-%H%M%S`
     # The umask for mergemaster to compare the	default	file's modes to	(-u)
     # The following options have no command line overrides
     # Files to	always avoid comparing
     #IGNORE_FILES='/etc/motd /etc/printcap foo	bar'
     # Additional options for diff.  This will get unset when using -s.
     #DIFF_OPTIONS='-Bb'     # Ignore changes in whitespace
     # Location	to store the list of mtree values for AUTO_UPGRADE purposes
     # For those who just cannot stand including the full path to PAGER
     # If you set 'yes'	above, make sure to include the	PATH to	your pager
     # Delete stale files in /etc/rc.d without prompting
     # Specify the path	to scripts to run before the comparison	starts,
     # and/or after the	script has finished its	work

     Exit status is 0 on successful completion,	or if the user bails out manu-
     ally at some point	during execution.

     Exit status is 1 if it fails for one of the following reasons:

     Invalid command line option

     Failure to	create the temporary root environment

     Failure to	populate the temporary root

     Presence of the 'nodev' option in _DESTDIR_/etc/fstab

     Failure to	install	a file

     Typically all you will need to do is type mergemaster at the prompt and
     the script	will do	all the	work for you.

     To	use context diffs and have mergemaster explain more things as it goes
     along, use:

	   # mergemaster -cv

     To	specify	that mergemaster put the temporary root	environment in
     /usr/tmp/root, use:

	   # mergemaster -t /usr/tmp/root

     To	specify	a 110 column screen with a strict comparison, use:

	   # mergemaster -sw 110

     diff(1), make(1), less(1),	sdiff(1), etcupdate(8),	pwd_mkdb(8)


     Nik Clayton, The Cutting Edge (using make world),

     The mergemaster utility was first publicly	available on one of my web
     pages in a	much simpler form under	the name comproot on 13	March 1998.
     The idea for creating the temporary root environment comes	from Nik Clay-
     ton's make	world tutorial which is	referenced above.

     This manual page and the script itself were written by Douglas Barton

FreeBSD	13.0			 March 2, 2023			  FreeBSD 13.0


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