better config file handling

[xfonts-traditional] / checkfiles

diff --git a/checkfiles b/checkfiles
index c3d325b..6336fda 100755 (executable)
--- a/checkfiles
+++ b/checkfiles
@@ -1,56 +1,72 @@
 #!/bin/sh
 # run from the prerm and postinst
-set -e
+set -ex
 
-install=$1
+script=$1
+mode=$2
 
-check_file () {
-       dckey=$1; regexp=$2; file=$3
-
-       if ! test -f $file; then return; fi
-
-       if $install; then
-               if test -e $file.not-trad; then return; fi
-               before=misc
-               after=trad
-               newfile=$file.trad
-               oldfile=$file.not-trad
-       else
-               if ! test -e $file.not-trad; then return; fi
-               before=trad
-               after=misc
-               newfile=$file.undo-trad
-               oldfile=$file.trad
-       fi
+. /usr/share/debconf/confmodule
 
+gen_file_overwrite () {
+       before=$1; after=$2; infile=$3; outfile=$4; backupmode=$5; backup=$6
        perl -pe '
  s/^('"$regexp"'\s+)\-'$before'\-(fixed-medium-r-semicondensed)/$1-'$after'-$2/
-               ' <$file >$file
-       if cmp -s $file $newfile; then
-               rm $newfile
+               ' <$infile >$outfile.tmp
+       if cmp -s $outfile.tmp $outfile; then
+               rm $outfile.tmp
                return
        fi
-
-       db_get $dckey
-       if [ $RET != true ]; then return; fi
-
-       if $install; then
-               db_get $dckey-done || true
-               if [ $RET = true ]; then return; fi
-
-               echo "Updating $file to use traditional fixed..."
-       else
-               echo "Restoring $file with nontraditional fixed..."
-       fi
-       rm -f $oldfile
-       ln $file $oldfile
-       mv -f $newfile $file
+       echo " Updating $file ($before=>$after)..."
+       case $backupmode in
+       once)
+               if ! test -e $backup; then
+                       ln $outfile $backup
+               fi
+               ;;
+       never)
+               ;;
+       esac
+       mv -f $outfile.tmp $outfile
 
        case "$file" in
        *.alias) update-fonts-alias misc ;;
        esac
+}
+
+check_file () {
+       dckey=$1; regexp=$2; file=$3
 
-       db_set $dckey-done $install
+       if ! test -f $file; then return; fi
+
+       needundo=true
+
+       case "$script.$mode" in
+       postinst.*)
+               db_get xfonts-traditional/$dckey ||:
+               if [ $RET = true ]; then
+                       gen_file_overwrite misc trad \
+                               $file $file once $file.backup.not-trad
+                       needundo=false
+               else
+                       gen_file_overwrite misc trad \
+                               $file $file.trad never
+               fi
+               ;;
+       prerm.upgrade*)
+               needundo=false
+               ;;
+       prerm.remove*)
+               ;;
+       *)
+               echo >&2 "huh $script.mode ?"
+               exit 1
+               ;;
+       esac
+       if $needundo && test -f $file.backup.not-trad; then
+               gen_file_overwrite trad misc \
+                       $file $file $file.backup.trad
+               mv -f $file.backup.not-trad $file.old.not-trad
+       fi
        # only ever do this once, unless we've actually undone it since
 }
 
@@ -62,3 +78,4 @@ check_file reconfigure-xterm '\*VT100\.utf8Fonts\.font\:' \
 check_file remap-fixed 'fixed' \
        /etc/X11/fonts/misc/xfonts-base.alias
 
+true