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

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

SYNOPSIS
     mergemaster [-scrvahipFCPU] [-m /path/to/sources] [-t /path/to/temp/root]
		 [-d] [-u N] [-w N] [-A Target architecture] [-D /destdir/path]

DESCRIPTION
     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 be-
     fore 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 install
     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 envi-
     ronment to merge by hand later.

     By default it creates the temporary root in /var/tmp/temproot and	compares
     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 strings.

     The merge menu option is designed to let you easily combine your customiza-
     tions 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 cus-
     tomized, it is not recommended.

     The mergemaster utility checks your umask and issues a warning for anything
     other  than 022.  While it is not mandatory to grant world read permissions
     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  up-
     dated  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  vari-
     ables in your .mergemasterrc file.  The script sourced before comparison 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 modi-
     fications, or files that you want to give special handling  to.   This  in-
     cludes  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.

     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, skipping
		 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 installed
		 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,  but  is  compatible  with  all
		 other options.  Setting [-a] makes [-w] superfluous.

     -h 	 Display usage and help information.

     -i 	 Automatically install any files that do not exist in the desti-
		 nation directory.

     -p 	 Pre-buildworld mode.  Compares only files known to be essential
		 to    the    success	 of    {build|install}world,   including
		 /etc/make.conf.

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

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

     -P 	 Preserve	files	    that       you	 replace      in
		 /var/tmp/mergemaster/preserved-files-<date>, or another  direc-
		 tory you specify in your mergemaster rc file.

     -U 	 Attempt to auto upgrade files that have not been user modified.

     -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 previous versions of mergemaster you needed
		 to  specify  the  path  all  the way to src/etc.  Starting with
		 r186678 you only need to specify the path to src.   mergemaster
		 will convert the path for you if you use the old method.

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

     -d 	 Add  the date and time to the name of the temporary root direc-
		 tory.	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.

ENVIRONMENT
     The mergemaster utility uses the PAGER environment variable if set.  Other-
     wise it uses more(1).  If PAGER specifies a  program  outside  its  limited
     PATH without specifying the full path, mergemaster prompts you with options
     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.

FILES
     /etc/mergemaster.rc
     $HOME/.mergemasterrc

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

     # These are options for mergemaster, with their default values listed
     # The following options have command line overrides
     #
     # The target architecture (unset by default)
     #ARCHSTRING='TARGET_ARCH=<foo>'
     #
     # Sourcedir is the directory to do the 'make' in (where the new files are)
     #SOURCEDIR='/usr/src'
     #
     # Directory to install the temporary root environment into
     #TEMPROOT='/var/tmp/temproot'
     #
     # Specify the destination directory for the installed files
     #DESTDIR=
     #
     # Strict comparison skips the VCS Id test and compares every file
     #STRICT=no
     #
     # Type of diff, such as unified, context, etc.
     #DIFF_FLAG='-u'
     #
     # Install the new file if it differs only by VCS Id ($FreeBSD)
     #FREEBSD_ID=
     #
     # Verbose mode includes more details and additional checks
     #VERBOSE=
     #
     # Automatically install files that do not exist on the system already
     #AUTO_INSTALL=
     #
     # Automatically upgrade files that have not been user modified
     #AUTO_UPGRADE=
     #
     # Compare /etc/rc.conf[.local] to /etc/defaults/rc.conf
     #COMP_CONFS=yes
     #
     # Preserve files that you replace
     #PRESERVE_FILES=yes
     #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
     #NEW_UMASK=022
     #
     # 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
     #MTREEDB='/var/db'
     #
     # For those who just cannot stand including the full path to PAGER
     #DONT_CHECK_PAGER=
     #
     # If you set 'yes' above, make sure to include the PATH to your pager
     #PATH=/bin:/usr/bin:/usr/sbin
     #
     # Specify the path to scripts to run before the comparison starts,
     # and/or after the script has finished its work
     #MM_PRE_COMPARE_SCRIPT=
     #MM_EXIT_SCRIPT=

EXIT STATUS
     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

EXAMPLES
     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

SEE ALSO
     diff(1), make(1), more(1), sdiff(1), pwd_mkdb(8)

     /usr/src/etc/Makefile

     Nik     Clayton,	  The	  Cutting     Edge     (using	 make	 world),
     http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html.

HISTORY
     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 Clayton's make
     world tutorial which is referenced above.

AUTHORS
     This manual page and the script  itself  were  written  by  Douglas  Barton
     <DougB@FreeBSD.org>.

BUGS
     There  are  no known bugs.  Please report any problems, comments or sugges-
     tions to the author.  Several of the improvements to this program have come
     from user suggestions.  Thank you.

FreeBSD 7.2			 March 18, 2009 		  MERGEMASTER(8)

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