Add several new features, reorder some code, and continue with the

process of making the script more cross platform friendly.

* Add -i option to automatically install files that do not exist
  on the system already.
* Add the ability to specify DESTDIR.
* Allow the user to specify scripts to run right before the
  comparison starts, and when mm is done. This will
  allow the user to specify customized local behavior, and
  implement features such as automatically deleting files.
* Document the above changes in the man page.
* Switch to using 'ident' for the CVS Id comparison, which
  should help with portability, and makes it faster.
* Reorder, and in one case fix some code by doing things in
  ways that make more sense.
* Check to see if the file exists on the system before doing
  the comparisons. This saves CPU cycles, and streamlines
  the auto-install process.

I used bits and pieces of suggestions and patches from various
people, ultimately too numerous to name. Which is not to say
that they were not both appreciated, and helpful in achieving
the ultimate result.

2 files changed, 194 insertions, 97 deletions

diff --git a/usr.sbin/mergemaster/mergemaster.8 b/usr.sbin/mergemaster/mergemaster.8
index e733c7c..65d22ae 100644
--- a/usr.sbin/mergemaster/mergemaster.8
+++ b/usr.sbin/mergemaster/mergemaster.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 10, 1999
+.Dd October 30, 2000
 .Dt MERGEMASTER 8
 .Os FreeBSD
 .Sh NAME
@@ -32,12 +32,13 @@
 .Nd Merge configuration files, et al during an upgrade
 .Sh SYNOPSIS
 .Nm
-.Op Fl scrvah
+.Op Fl scrvahi
 .Op Fl m Ar /path/to/sources
 .Op Fl t Ar /path/to/temp/root
 .Op Fl d
 .Op Fl u Ar N
 .Op Fl w Ar N
+.Op Fl D Ar /path
 .Sh DESCRIPTION
 .Nm
 is a Bourne shell script which is designed to aid you
@@ -58,7 +59,10 @@ files.
 You can specify a different source directory
 with the
 .Op Fl m
-command line option.
+command line option, or specify the destination
+directory with the
+.Op Fl D
+option.
 It then compares each file in that environment
 to its installed counterpart.
 When the script finds a
@@ -113,6 +117,26 @@ and file permissions as specified by the umask.
 Unified diffs are used by default to display any
 differences unless you choose context diffs.
 .Pp
+.Nm
+will source scripts that you specify right before
+it starts the comparison, and after it's done running.
+The easiest way to handle this is to place the path
+to the script(s) in the appropriate variables in your
+.Pa .mergemasterrc
+file.
+The script sourced before comparison is named in
+.Ev MM_PRE_COMPARE_SCRIPT ,
+and the one sourced after the script is done is
+.Ev 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
+.Nm ,
+all of the script's variables are available for use in
+your custom script.
+.Pp
 The options are as follows:
 .Bl -tag -width Fl
 .It Fl s
@@ -149,6 +173,9 @@ Setting -a makes
 -w superfluous.
 .It Fl h
 Display usage and help information.
+.It Fl i
+Automatically install any files that do not exist in the
+destination directory.
 .It Fl m Ar /path/to/sources
 Specify the path to the directory where you want to do the
 .Xr make 1 .
@@ -172,6 +199,8 @@ Supply an alternate screen width to the
 .Xr sdiff 1
 command in numbers of columns.
 The default is 80.
+.It Fl D Ar /path
+Specify the destination directory for the installed files.
 .El
 .Sh ENVIRONMENT
 The
@@ -190,6 +219,15 @@ limited
 without specifying the full path,
 .Nm
 prompts you with options on how to proceed.
+The
+.Ev MM_PRE_COMPARE_SCRIPT
+and
+.Ev MM_EXIT_SCRIPT
+variables are used as described above.
+Other variables that are used by the script internally
+can be specified in
+.Pa .mergemasterrc
+as described in more detail below.
 .Sh EXAMPLES
 Typically all you will need to do is type
 .Nm
@@ -240,19 +278,33 @@ with all values commented out:
 # Verbose mode includes more details and additional checks
 #VERBOSE=
 #
+# Automatically install files that do not exist on the system already
+#AUTO_INSTALL=
+#
 # Sourcedir is the directory to do the 'make' in (where the new files are)
-#SOURCEDIR=/usr/src/etc
+#SOURCEDIR='/usr/src/etc'
 #
 # The umask for mergemaster to compare the default file's modes to
 #NEW_UMASK=022
 #
+# Specify the destination directory for the installed files
+#DESTDIR=
+#
 # The following options have no command line overrides
 # 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
+#PATH=/bin:/usr/bin:/usr/sbin:/sbin
+#
 # Don't compare the old and new motd files
 #IGNORE_MOTD=yes
+#
+# 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=
+
 .Ed
 .Sh SEE ALSO
 .Xr cvs 1 ,
@@ -291,7 +343,7 @@ make world tutorial which is referenced above.
 .Pp
 .Sh AUTHOR
 This manual page and the script itself were written by
-.An Douglas Barton Aq Doug@gorean.org .
+.An Douglas Barton Aq DougB@FreeBSD.org .
 .Sh BUGS
 There are no known bugs.
 Please report any problems,
diff --git a/usr.sbin/mergemaster/mergemaster.sh b/usr.sbin/mergemaster/mergemaster.sh
index 4900d12..8b38a55 100755
--- a/usr.sbin/mergemaster/mergemaster.sh
+++ b/usr.sbin/mergemaster/mergemaster.sh
@@ -15,7 +15,8 @@ PATH=/bin:/usr/bin:/usr/sbin:/sbin
 display_usage () {
   VERSION_NUMBER=`grep "[$]FreeBSD:" $0 | cut -d ' ' -f 4`
   echo "mergemaster version ${VERSION_NUMBER}"
-  echo "Usage: mergemaster [-scrvah] [-m /path] [-t /path] [-d] [-u N] [-w N]"
+  echo 'Usage: mergemaster [-scrvahi] [-m /path]'
+  echo '         [-t /path] [-d] [-u N] [-w N] [-D /path]'
   echo "Options:"
   echo "  -s  Strict comparison (diff every pair of files)"
   echo "  -c  Use context diff instead of unified diff"
@@ -23,26 +24,24 @@ display_usage () {
   echo "  -v  Be more verbose about the process, include additional checks"
   echo "  -a  Leave all files that differ to merge by hand"
   echo "  -h  Display more complete help"
+  echo '  -i  Automatically install files that do not exist in destination directory'
   echo "  -m /path/directory  Specify location of source to do the make in"
   echo "  -t /path/directory  Specify temp root directory"
   echo "  -d  Add date and time to directory name (e.g., /var/tmp/temproot.`date +%m%d.%H.%M`)"
   echo "  -u N  Specify a numeric umask"
   echo "  -w N  Specify a screen width in columns to sdiff"
+  echo '  -D /path/directory  Specify the destination directory to install files to'
   echo ''
 }
 
 display_help () {
-  echo "* To create a temporary root environment, compare CVS revision \$Ids"
-  echo "  for files that have them, and compare diffs for files that do not,"
-  echo "  or have different ones, just type, mergemaster"
   echo "* To specify a directory other than /var/tmp/temproot for the"
   echo "  temporary root environment, use -t /path/to/temp/root"
   echo "* The -w option takes a number as an argument for the column width"
   echo "  of the screen.  The default is 80."
-  echo "* The -a option causes mergemaster to run without prompting"
+  echo '* The -a option causes mergemaster to run without prompting.'
 }
 
-
 # Loop allowing the user to use sdiff to merge files and display the merged
 # file.
 merge_loop () {
@@ -58,7 +57,7 @@ merge_loop () {
     # Prime file.merged so we don't blat the owner/group id's
     cp -p "${COMPFILE}" "${COMPFILE}.merged"
     sdiff -o "${COMPFILE}.merged" --text --suppress-common-lines \
-      --width=${SCREEN_WIDTH:-80} "${COMPFILE#.}" "${COMPFILE}"
+      --width=${SCREEN_WIDTH:-80} "${DESTDIR}${COMPFILE#.}" "${COMPFILE}"
     INSTALL_MERGED=V
     while [ "${INSTALL_MERGED}" = "v" -o "${INSTALL_MERGED}" = "V" ]; do
       echo ''
@@ -107,18 +106,36 @@ diff_loop () {
   HANDLE_COMPFILE=v
 
   while [ "${HANDLE_COMPFILE}" = "v" -o "${HANDLE_COMPFILE}" = "V" -o "${HANDLE_COMPFILE}" = "NOT V" ]; do
-    if [ -f "${COMPFILE#.}" -a -f "${COMPFILE}" ]; then
+    if [ -f "${DESTDIR}${COMPFILE#.}" -a -f "${COMPFILE}" ]; then
       if [ "${HANDLE_COMPFILE}" = "v" -o "${HANDLE_COMPFILE}" = "V" ]; then
         (
+          echo ''
           echo "  *** Displaying differences between ${COMPFILE} and installed version:"
           echo ''
-        diff "${DIFF_FLAG}" "${COMPFILE#.}" "${COMPFILE}"
+          diff "${DIFF_FLAG}" "${DESTDIR}${COMPFILE#.}" "${COMPFILE}"
         ) | ${PAGER}
         echo ''
       fi
     else
+      echo ''
       echo "  *** There is no installed version of ${COMPFILE}"
-      NO_INSTALLED=yes
+      case "${AUTO_INSTALL}" in
+      [Yy][Ee][Ss])
+        echo ''
+        if mm_install "${COMPFILE}"; then
+          echo "   *** ${COMPFILE} installed successfully"
+          # Make the list print one file per line
+          AUTO_INSTALLED_FILES="${AUTO_INSTALLED_FILES}      ${DESTDIR}${COMPFILE#.}
+"
+        else
+          echo "   *** Problem installing ${COMPFILE}, it will remain to merge by hand"
+        fi
+        return
+        ;;
+      *)
+        NO_INSTALLED=yes
+        ;;
+      esac
     fi
 
     echo "  Use 'd' to delete the temporary ${COMPFILE}"
@@ -179,7 +196,6 @@ diff_loop () {
       ;;
     esac  # End of "How to handle files that are different"
   done
-  echo ''
   unset NO_INSTALLED
   echo ''
   case "${VERBOSE}" in
@@ -196,13 +212,13 @@ TEMPROOT='/var/tmp/temproot'
 
 # Read .mergemasterrc before command line so CLI can override
 #
-if [ -f "$HOME/.mergemasterrc" ]; then
+if [ -r "$HOME/.mergemasterrc" ]; then
   . "$HOME/.mergemasterrc"
 fi
 
 # Check the command line options
 #
-while getopts ":ascrvhm:t:du:w:" COMMAND_LINE_ARGUMENT ; do
+while getopts ":ascrvhim:t:du:w:D:" COMMAND_LINE_ARGUMENT ; do
   case "${COMMAND_LINE_ARGUMENT}" in
   s)
     STRICT=yes
@@ -227,6 +243,9 @@ while getopts ":ascrvhm:t:du:w:" COMMAND_LINE_ARGUMENT ; do
     display_help
     exit 0
     ;;
+  i)
+    AUTO_INSTALL=yes
+    ;;
   m)
     SOURCEDIR=${OPTARG}
     ;;
@@ -242,6 +261,9 @@ while getopts ":ascrvhm:t:du:w:" COMMAND_LINE_ARGUMENT ; do
   w)
     SCREEN_WIDTH=${OPTARG}
     ;;
+  D)
+    DESTDIR=${OPTARG}
+    ;;
   *)
     display_usage
     exit 1
@@ -406,6 +428,7 @@ case "${RERUN}" in
   esac
 
   { cd ${SOURCEDIR} &&
+    make DESTDIR=${DESTDIR} distrib-dirs &&
     make DESTDIR=${TEMPROOT} distrib-dirs &&
     make DESTDIR=${TEMPROOT} -DNO_MAKEDEV distribution;} ||
   { echo '';
@@ -414,11 +437,33 @@ case "${RERUN}" in
     echo '';
     exit 1;}
 
+  # Doing the inventory and removing files that we don't want to compare only makes
+  # sense if we are not doing a rerun, since we have no way of knowing what happened
+  # to the files during previous incarnations.
+  case "${VERBOSE}" in
+  '') ;;
+  *)
+    echo ''
+    echo ' *** The following files exist only in the installed version of'
+    echo "     ${DESTDIR}/etc.  In the vast majority of cases these files"
+    echo '     are necessary parts of the system and should not be deleted.'
+    echo '     However because these files are not updated by this process you'
+    echo '     might want to verify their status before rebooting your system.'
+    echo ''
+    echo ' *** Press [Enter] or [Return] key to continue'
+    read ANY_KEY
+    unset ANY_KEY
+    diff -qr ${DESTDIR}/etc ${TEMPROOT}/etc | grep "^Only in /etc" | ${PAGER}
+    echo ''
+    echo ' *** Press [Enter] or [Return] key to continue'
+    read ANY_KEY
+    unset ANY_KEY
+    ;;
+  esac
+
   # We really don't want to have to deal with these files, since
   # master.passwd is the real file that should be compared, then
   # the user should run pwd_mkdb if necessary.
-  # Only do this if we are not rerun'ing, since if we are the
-  # files will not be there.
   #
   rm ${TEMPROOT}/etc/spwd.db ${TEMPROOT}/etc/passwd ${TEMPROOT}/etc/pwd.db
 
@@ -439,27 +484,6 @@ esac
 
 # Get ready to start comparing files
 
-case "${VERBOSE}" in
-'') ;;
-*)
-  echo ''
-  echo " *** The following files exist only in the installed version"
-  echo "     of /etc.  In the far majority of cases these files are"
-  echo "     necessary parts of the system and should not be deleted,"
-  echo "     however because these files are not updated by this process"
-  echo "     you might want to verify their status before rebooting your system."
-  echo ''
-  echo " *** Press [Enter] or [Return] key to continue"
-  read ANY_KEY
-  unset ANY_KEY
-  diff -qr /etc ${TEMPROOT}/etc | grep "^Only in /etc" | ${PAGER}
-  echo ''
-  echo " *** Press [Enter] or [Return] key to continue"
-  read ANY_KEY
-  unset ANY_KEY
-  ;;
-esac
-
 # Check umask if not specified on the command line,
 # and we are not doing an autorun
 #
@@ -490,15 +514,18 @@ fi
 
 CONFIRMED_UMASK=${NEW_UMASK:-0022}
 
-# Warn users who have an /etc/sysconfig file
+# Warn users who still have ${DESTDIR}/etc/sysconfig
 #
-if [ -f /etc/sysconfig ]; then
-  echo " *** There is an /etc/sysconfig file on this system.  Starting with"
-  echo "     FreeBSD version 2.2.2 those settings have moved from /etc/sysconfig"
-  echo "     to /etc/rc.conf.  If you are upgrading an older system make sure"
-  echo "     that you transfer your settings by hand from sysconfig to rc.conf and"
-  echo "     install the rc.conf file.  If you have already made this transition,"
-  echo "     you should consider renaming or deleting the /etc/sysconfig file."
+if [ -e "${DESTDIR}/etc/sysconfig" ]; then
+  echo ''
+  echo " *** There is a sysconfig file on this system in ${DESTDIR}/etc/."
+  echo ''
+  echo '     Starting with FreeBSD version 2.2.2 those settings moved from'
+  echo '     /etc/sysconfig to /etc/rc.conf.  If you are upgrading an older'
+  echo '     system make sure that you transfer your settings by hand from'
+  echo '     sysconfig to rc.conf and install the rc.conf file.  If you'
+  echo '     have already made this transition, you should consider'
+  echo '     renaming or deleting the sysconfig file.'
   echo ''
   case "${AUTO_RUN}" in
   '')
@@ -519,12 +546,6 @@ if [ -f /etc/sysconfig ]; then
   esac
 fi
 
-echo ''
-echo "*** Beginning comparison"
-echo ''
-
-cd "${TEMPROOT}"
-
 # Use the umask/mode information to install the files
 # Create directories as needed
 #
@@ -532,24 +553,22 @@ mm_install () {
   local INSTALL_DIR
   INSTALL_DIR=${1#.}
   INSTALL_DIR=${INSTALL_DIR%/*}
+
   case "${INSTALL_DIR}" in
   '')
     INSTALL_DIR=/
     ;;
   esac
 
-  if [ -n "${INSTALL_DIR}" -a ! -d "${INSTALL_DIR}" ]; then
+  if [ -n "${DESTDIR}${INSTALL_DIR}" -a ! -d "${DESTDIR}${INSTALL_DIR}" ]; then
     DIR_MODE=`perl -e 'printf "%04o\n", (((stat("$ARGV[0]"))[2] & 07777) &~ oct("$ARGV[1]"))' "${TEMPROOT}/${INSTALL_DIR}" "${CONFIRMED_UMASK}"`
-    install -d -o root -g wheel -m "${DIR_MODE}" "${INSTALL_DIR}"
+    install -d -o root -g wheel -m "${DIR_MODE}" "${DESTDIR}${INSTALL_DIR}"
   fi
 
   FILE_MODE=`perl -e 'printf "%04o\n", (((stat("$ARGV[0]"))[2] & 07777) &~ oct("$ARGV[1]"))' "${1}" "${CONFIRMED_UMASK}"`
 
   if [ ! -x "${1}" ]; then
     case "${1#.}" in
-    /dev/MAKEDEV)
-      NEED_MAKEDEV=yes
-      ;;
     /etc/mail/aliases)
       NEED_NEWALIASES=yes
       ;;
@@ -557,7 +576,7 @@ mm_install () {
       NEED_CAP_MKDB=yes
       ;;
     /etc/master.passwd)
-      install -m 600 "${1}" "${INSTALL_DIR}"
+      install -m 600 "${1}" "${DESTDIR}${INSTALL_DIR}"
       NEED_PWD_MKDB=yes
       DONT_INSTALL=yes
       ;;
@@ -575,7 +594,7 @@ mm_install () {
       esac
 
       echo "   Use 'd' to delete the temporary ${COMPFILE}"
-      echo "   Use 'l' to delete the existing ${COMPFILE#.} and create the link"
+      echo "   Use 'l' to delete the existing ${DESTDIR}${COMPFILE#.} and create the link"
       echo ''
       echo "   Default is to leave the temporary file to deal with by hand"
       echo ''
@@ -590,14 +609,12 @@ mm_install () {
         ;;
       [lL]*)
         echo ''
-        if [ -e "${COMPFILE#.}" ]; then
-          rm "${COMPFILE#.}"
-        fi
-        if ln "/root/${COMPFILE##*/}" "${COMPFILE#.}"; then
-          echo "   *** Link from ${COMPFILE#.} to /root/${COMPFILE##*/} installed successfully"
+        rm -f "${DESTDIR}${COMPFILE#.}"
+        if ln "${DESTDIR}/root/${COMPFILE##*/}" "${DESTDIR}${COMPFILE#.}"; then
+          echo "   *** Link from ${DESTDIR}${COMPFILE#.} to ${DESTDIR}/root/${COMPFILE##*/} installed successfully"
           rm "${COMPFILE}"
         else
-          echo "   *** Error linking ${COMPFILE#.} to /root/${COMPFILE##*/}, ${COMPFILE} will remain to install by hand"
+          echo "   *** Error linking ${DESTDIR}${COMPFILE#.} to ${DESTDIR}/root/${COMPFILE##*/}, ${COMPFILE} will remain to install by hand"
         fi
         ;;
       *)
@@ -610,56 +627,68 @@ mm_install () {
 
     case "${DONT_INSTALL}" in
     '')
-      install -m "${FILE_MODE}" "${1}" "${INSTALL_DIR}"
+      install -m "${FILE_MODE}" "${1}" "${DESTDIR}${INSTALL_DIR}"
       ;;
     *)
       unset DONT_INSTALL
       ;;
     esac
-
   else
-    install -m "${FILE_MODE}" "${1}" "${INSTALL_DIR}"
+    case "${1#.}" in
+    /dev/MAKEDEV)
+      NEED_MAKEDEV=yes
+      ;;
+    esac
+    install -m "${FILE_MODE}" "${1}" "${DESTDIR}${INSTALL_DIR}"
   fi
   return $?
 }
 
-compare_ids () {
-  case "${1}" in
- "${2}")
-    echo " *** Temp ${COMPFILE} and installed have the same ${IDTAG}, deleting"
-    rm "${COMPFILE}"
-    ;;
-  esac
-}
+echo ''
+echo "*** Beginning comparison"
+echo ''
+
+cd "${TEMPROOT}"
+
+if [ -r "${MM_PRE_COMPARE_SCRIPT}" ]; then
+  . "${MM_PRE_COMPARE_SCRIPT}"
+fi
 
 # Using -size +0 avoids uselessly checking the empty log files created
 # by ${SOURCEDIR}/Makefile and the device entries in ./dev, but does
-# check the scripts in ./dev, as we'd like.
+# check the scripts in ./dev, as we'd like (assuming no devfs of course).
 #
 for COMPFILE in `find . -type f -size +0`; do
+
+  # First, check to see if the file exists in DESTDIR.  If not, the
+  # diff_loop function knows how to handle it.
+  #
+  if [ ! -e "${DESTDIR}${COMPFILE#.}" ]; then
+    diff_loop
+    continue
+  fi
+
   case "${STRICT}" in
   '' | [Nn][Oo])
     # Compare CVS $Id's first so if the file hasn't been modified
     # local changes will be ignored.
     # If the files have the same $Id, delete the one in temproot so the
     # user will have less to wade through if files are left to merge by hand.
-    # Take the $Id -> $FreeBSD tag change into account
     #
-    FREEBSDID1=`grep "[$]FreeBSD:" ${COMPFILE#.} 2>/dev/null`
-    FREEBSDID2=`grep "[$]FreeBSD:" ${COMPFILE} 2>/dev/null`
-
-    if [ -n "${FREEBSDID1}" -a -n "${FREEBSDID2}" ]; then
-      IDTAG='$FreeBSD'
-      compare_ids "${FREEBSDID1}" "${FREEBSDID2}"
-    else
-      CVSID1=`grep "[$]Id:" ${COMPFILE#.} 2>/dev/null`
-      CVSID2=`grep "[$]Id:" ${COMPFILE} 2>/dev/null`
+    # Reduce complexity and improve portability by using ident
+    #
+    CVSID1=`ident ${DESTDIR}${COMPFILE#.} 2>&1`
+    CVSID1="${CVSID1#${DESTDIR}}"
+    CVSID2=`ident ${COMPFILE} 2>&1`
 
-      if [ -n "${CVSID1}" -a -n "${CVSID2}" ]; then
-        IDTAG='$Id'
-        compare_ids "${CVSID1}" "${CVSID2}"
-      fi
-    fi
+    case "${CVSID2}" in
+    *'no id keywords'*)
+      ;;
+    ."${CVSID1}")
+      echo " *** Temp ${COMPFILE} and installed have the same CVS Id, deleting"
+      rm "${COMPFILE}"
+      ;;
+    esac
     ;;
   esac
 
@@ -671,7 +700,7 @@ for COMPFILE in `find . -type f -size +0`; do
     # Do an absolute diff first to see if the files are actually different.
     # If they're not different, delete the one in temproot.
     #
-    if diff -q "${COMPFILE#.}" "${COMPFILE}" > /dev/null 2>&1; then
+    if diff -q "${DESTDIR}${COMPFILE#.}" "${COMPFILE}" > /dev/null 2>&1; then
       echo " *** Temp ${COMPFILE} and installed are the same, deleting"
       rm "${COMPFILE}"
     else
@@ -761,7 +790,23 @@ case "${NEED_PWD_MKDB}" in
   ;;
 esac
 
+case "${AUTO_INSTALLED_FILES}" in
+'') ;;
+*)
+  (
+    echo ''
+    echo '*** You chose the automatic install option for files that did not exist'
+    echo '    on your system.  The following files were installed for you:'
+    echo "${AUTO_INSTALLED_FILES}"
+  ) | ${PAGER}
+  ;;
+esac
+
 echo ''
 
+if [ -r "${MM_EXIT_SCRIPT}" ]; then
+  . "${MM_EXIT_SCRIPT}"
+fi
+
 exit 0