roles/base/apt/files/default/ucf.bin

   1 #!/bin/sh
   2 ################################################
   3 ### Managed by someone's ansible provisioner ###
   4 ################################################
   5 # Part of: https://git.somenet.org/root/pub/somesible.git
   6 # 2017-2025 by someone <someone@somenet.org>
   7 #
   8
   9 # make sure we exit on error
  10 set -e
  11
  12 # Sanitise environment
  13 while read -r env ; do
  14     case "$env" in
  15         '') continue ;;
  16         OPTIND) ;; # Dash croaks when unsetting OPTIND. See #985478
  17         PATH|PWD|TERM) ;;
  18         LANGUAGE|LANG|LC_*) ;;
  19         DEB_*|DEBIAN_*|DEBCONF_*) ;;
  20         DPKG_FORCE) ;;
  21         UCF_*) ;;
  22         *) unset "$env" ;;
  23     esac
  24 done<<EOF
  25 $(awk 'BEGIN{for(v in ENVIRON) print v}')
  26 EOF
  27
  28 # set the version and revision
  29 progname="$(basename "$0")"
  30 pversion='3.0052'
  31
  32 ######################################################################
  33 ########                                                     #########
  34 ########              Utility functions                      #########
  35 ########                                                     #########
  36 ######################################################################
  37 for libdir in "$(dirname "$0")" /usr/share/ucf ; do
  38     [ -f "${libdir}/ucf_library.sh" ] && \
  39         . "${libdir}/ucf_library.sh" && \
  40         break
  41 done
  42
  43 # Usage: get_file_metadate file_name
  44 get_file_metadata()
  45 {
  46     if [ -e "$1" ]; then
  47         # get file modification date without the nanoseconds and timezone info
  48         moddate="$(date +"%F %T" --date "$(stat --format '@%Y' "$1")")"
  49         # print file_name user.group permissions above_date
  50         stat --format "%n %U.%G 0%a $moddate" "$1"
  51     else
  52         echo "/dev/null"
  53     fi
  54 }
  55
  56 # Runs the diff command with approrpiate arguments
  57 # Usage run_diff diff|sdiff diff_opts old_file new_file
  58 run_diff()
  59 {
  60     local diff_cmd diff_opt old_file new_file old_file_label new_file_label out
  61     diff_cmd="$1"
  62     diff_opt="$2"
  63     old_file="$3"
  64     new_file="$4"
  65
  66     old_file_label="$(get_file_metadata "$old_file")"
  67     new_file_label="$(get_file_metadata "$new_file")"
  68
  69     [ -e "$old_file" ] || old_file=/dev/null
  70     [ -e "$new_file" ] || new_file=/dev/null
  71
  72     if [ "$diff_cmd" = "diff" ] ; then
  73       diff "$diff_opt" --label "$old_file_label" "$old_file" \
  74             --label "$new_file_label" "$new_file" || true
  75     elif [ "$diff_cmd" = "sdiff" ] ; then
  76       # unfortunatelly the sdiff command does not support --label option
  77       out="$(sdiff "$diff_opt" "$old_file" "$new_file")" || true
  78       [ -z "$out" ] || printf "Old file: %s\nNew file: %s\n\n%s" \
  79                                "$old_file_label" "$new_file_label" "$out"
  80     else
  81       echo "Unknown diff command: $diff_cmd" >&2
  82       exit 1
  83     fi
  84 }
  85
  86 # Use debconf to show the differences
  87 # Usage: show_diff actual_file_differences file_stat_differences
  88 show_diff() {
  89     if [ -z "$1" ]; then
  90         DIFF="There are no non-white space differences in the files."
  91     else
  92         if  [ 99999 -lt "$(echo "$1" | wc -c | awk '{print $1; }')" ]; then
  93             DIFF="The differences between the files are too large to display."
  94         else
  95             # Try to convert non-breaking space to current locale
  96             nbsp=$(printf '\302\240' | iconv -c --from-code=UTF-8 --to-code=//TRANSLIT)
  97             DIFF="$(printf "%s" "$1" | sed "s/ /${nbsp:- }/g" | debconf-escape -e )"
  98         fi
  99     fi
 100     if [ "$DEBCONF_OK" = "YES" ] && [ "$DEBIAN_HAS_FRONTEND" ]; then
 101         templ=ucf/show_diff
 102         db_capb escape
 103         db_subst $templ DIFF "$DIFF"
 104         db_fset $templ seen false
 105         db_input critical $templ || true
 106         db_go || true
 107         db_get $templ
 108         # may contain sensitive information, so clear
 109         # immediatly after use so it is never written
 110         # to disk
 111         db_subst $templ DIFF ""
 112         db_reset $templ
 113         db_capb
 114     else
 115         if [ -z "$my_pager" ]; then
 116             echo "$DIFF" | sensible-pager
 117         else
 118             echo "$DIFF" | $my_pager
 119         fi
 120     fi
 121 }
 122
 123 usageversion () {
 124         cat >&2 <<END
 125 Debian GNU/Linux $progname $pversion.
 126            Copyright (C) 2002-2020 Manoj Srivastava.
 127            Copyright (C) 2024- Mark Hindley.
 128 This is free software; see the GNU General Public Licence for copying
 129 conditions.  There is NO warranty.
 130
 131 Usage: $progname  [options] new_file  destination
 132 Options:
 133      -h,     --help          print this message
 134      -s foo, --src-dir  foo  Set the src dir (historical md5sums live here)
 135              --sum-file bar  Force the historical md5sums to be read from
 136                              this file.  Overrides any setting of --src-dir.
 137      -d[n], --debug=[n]      Set the Debug level to N. Please note there must
 138                              be no spaces before the debug level
 139      -n,     --no-action     Dry run. No action is actually taken.
 140      -P foo, --package foo   Don't follow dpkg-divert diversions by package foo.
 141      -v,     --verbose       Make the script verbose
 142              --three-way     Register this file in the cache, and turn on the
 143                              diff3 option allowing the merging of maintainer
 144                              changes into a (potentially modified) local
 145                              configuration file. )
 146              --state-dir bar Set the state directory to bar instead of the
 147                              default '/var/lib/ucf'. Used mostly for testing.
 148              --debconf-ok    Indicate that it is ok for ucf to use an already
 149                              running debconf instance for prompting.
 150              --debconf-template bar
 151                              Specify an alternate, caller-provided debconf
 152                              template to use for prompting.
 153 Usage: $progname  -p  destination
 154      -p,     --purge         Remove any reference to destination from records
 155
 156 By default, the directory the new_file lives in is assumed to be the src-dir,
 157 which is where we look for any historical md5sums.
 158
 159 END
 160
 161 }
 162
 163 ######################################################################
 164 ########                                                     #########
 165 ########        file and hash save/restore functions         #########
 166 ########                                                     #########
 167 ######################################################################
 168 purge_md5sum () {
 169     for i in $(/usr/bin/seq 6 -1 0); do
 170         if [ -e "${statedir}/hashfile.${i}" ]; then
 171             if [ "$docmd" = "YES" ]; then
 172                 cp -pf "${statedir}/hashfile.${i}" \
 173                     "${statedir}/hashfile.$(($i+1))"
 174             else
 175                 echo cp -pf "${statedir}/hashfile.${i}" \
 176                           "${statedir}/hashfile.$(($i+1))"
 177             fi
 178         fi
 179     done
 180     if [ -e "$statedir/hashfile" ]; then
 181         if [ "$docmd" = "YES" ]; then
 182             cp -pf "$statedir/hashfile"  "$statedir/hashfile.0"
 183         else
 184             echo cp -pf "$statedir/hashfile"  "$statedir/hashfile.0"
 185         fi
 186         if [ "$docmd" = "YES" ]; then
 187             if [ "$VERBOSE" ]; then
 188                 echo >&2 "grep -v ${dest_file_bre} $statedir/hashfile"
 189                 grep -v "${dest_file_bre}"  "$statedir/hashfile" >&2 \
 190                     || true
 191             fi
 192             grep -v "${dest_file_bre}" "$statedir/hashfile" > \
 193                 "$statedir/hashfile.tmp" || true
 194             mv -f "$statedir/hashfile.tmp"  "$statedir/hashfile"
 195         fi
 196     fi
 197     [ "$VERBOSE" ] && echo >&2 "The cache file is $cached_file"
 198     if [ "$cached_file" ] && [ -f "$statedir/cache/$cached_file" ]; then
 199         $action rm -f "$statedir/cache/$cached_file"
 200     fi
 201 }
 202
 203 replace_md5sum () {
 204     for i in $(/usr/bin/seq 6 -1 0); do
 205         if [ -e "${statedir}/hashfile.${i}" ]; then
 206             if [ "$docmd" = "YES" ]; then
 207                 cp -pf "${statedir}/hashfile.${i}" \
 208                     "${statedir}/hashfile.$(($i+1))"
 209             else
 210                 echo cp -pf "${statedir}/hashfile.${i}" \
 211                     "${statedir}/hashfile.$(($i+1))"
 212             fi
 213         fi
 214     done
 215     if [ -e "$statedir/hashfile" ]; then
 216         if [ "$docmd" = "YES" ]; then
 217             cp -pf "$statedir/hashfile"  "$statedir/hashfile.0"
 218         else
 219             echo cp -pf "$statedir/hashfile"  "$statedir/hashfile.0"
 220         fi
 221         if [ "$docmd" = "YES" ]; then
 222             if [ "$VERBOSE" ]; then
 223                 echo >&2 "grep -v \"${dest_file_bre}\" \"$statedir/hashfile\""
 224                 grep -v "${dest_file_bre}" "$statedir/hashfile" >&2 || true
 225                 md5sum "$orig_new_file" | sed "s|$orig_new_file|$dest_file|" >&2
 226             fi
 227             grep -v "${dest_file_bre}" "$statedir/hashfile" > \
 228                 "$statedir/hashfile.tmp" || true
 229             md5sum "$orig_new_file" | sed "s|$orig_new_file|$dest_file|" >> \
 230                 "$statedir/hashfile.tmp"
 231             mv -f "$statedir/hashfile.tmp"  "$statedir/hashfile"
 232         else
 233             echo "(grep -v \"${dest_file_bre}\" \"$statedir/hashfile\""
 234             echo " md5sum \"$orig_new_file\" | sed \"s|$orig_new_file|$dest_file|\"; "
 235             echo ") | sort > \"$statedir/hashfile\""
 236         fi
 237     else
 238         if [ "$docmd" = "YES" ]; then
 239             md5sum "$orig_new_file" | sed "s|$orig_new_file|$dest_file|"  > \
 240                 "$statedir/hashfile"
 241         else
 242             echo " md5sum \"$orig_new_file\" | sed \"s|$orig_new_file|$dest_file|\" >" \
 243                 "\"$statedir/hashfile\""
 244         fi
 245     fi
 246     file_size=$(stat -c '%s' "$orig_new_file")
 247     if [ "$THREEWAY" ] || [ "$file_size" -lt 25600 ]; then
 248         $action cp -pf "$orig_new_file" "$statedir/cache/$cached_file"
 249     fi
 250     # cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
 251 }
 252
 253 replace_conf_file () {
 254     # do not mangle $dest_file since it's the one registered in the hashfile
 255     # or we have been ask to register
 256     real_file="$dest_file"
 257     if [ -L "$dest_file" ]; then
 258         real_file="$(readlink -nf "$dest_file" || :)"
 259         if [ ! "$real_file" ]; then
 260             echo >&2 "$dest_file is a broken symlink!"
 261             $action rm -f "$dest_file"
 262             real_file="$dest_file"
 263         fi
 264     fi
 265     if [ -e "$real_file" ]; then
 266         if [ -z "$RETAIN_OLD" ]; then
 267             #echo "Saving  ${real_file}.${OLD_SUFFIX},  in case."
 268             [ "$VERBOSE" ] &&
 269                 echo >&2 "Not saving ${real_file}, since it was unmodified"
 270         else
 271             $action cp -pf $selinux "${real_file}" "${real_file}.${OLD_SUFFIX}"
 272         fi
 273     fi
 274     if [ -e "${real_file}" ]; then
 275         # Do not change the permissions and attributes of the destination
 276         $action cp -f $selinux "$new_file" "${real_file}"
 277     else
 278         # No destination file exists
 279         $action cp -pf $selinux "$new_file" "${real_file}"
 280     fi
 281     replace_md5sum
 282 }
 283
 284 ######################################################################
 285 ########                                                     #########
 286 ########              Command line args                      #########
 287 ########                                                     #########
 288 ######################################################################
 289 #
 290 # Long term variables
 291 #
 292 docmd='YES'
 293 # action='withecho'
 294 action=
 295 selinux=''
 296 DEBUG=0
 297 VERBOSE=''
 298 statedir='/var/lib/ucf'
 299 THREEWAY=
 300 DIST_SUFFIX="ucf-dist"
 301 NEW_SUFFIX="ucf-new"
 302 OLD_SUFFIX="ucf-old"
 303 ERR_SUFFIX="merge-error"
 304
 305 handle_file_args() {
 306     if [ "$PURGE" = "YES" ]; then
 307         if [ $# -ne 1 ]; then
 308             echo >&2 "*** ERROR: Need exactly one file argument when purging, got $#"
 309             echo >&2 ""
 310             usageversion
 311             exit 2
 312         fi
 313         temp_dest_file="$1"
 314         if [ -e "$temp_dest_file" ]; then
 315             dest_file=$(vset "$(readlink -q -m "$temp_dest_file")" "The Destination file")
 316         else
 317             dest_file=$(vset "$temp_dest_file" "The Destination file")
 318         fi
 319     else
 320         if [ $# -ne 2 ]; then
 321             echo >&2 "*** ERROR: Need exactly two file arguments, got $#"
 322             echo >&2 ""
 323             usageversion
 324             exit 2
 325         fi
 326         temp_new_file="$1"
 327         temp_dest_file="$2"
 328
 329         if [ ! -e "${temp_new_file}" ]; then
 330             echo >&2 "Error: The new file ${temp_new_file} does not exist!"
 331             exit 1
 332         fi
 333         new_file=$(vset "$(readlink -q -m "$temp_new_file")"  "The new file")
 334         if [ -e "$temp_dest_file" ]; then
 335             dest_file=$(vset "$(readlink -q -m "$temp_dest_file")" "The Destination file")
 336         else
 337             dest_file=$(vset "$temp_dest_file" "The Destination file")
 338         fi
 339     fi
 340 }
 341
 342 handle_opts() {
 343     # Arguments are from getopt(1) in quoted mode.
 344     eval set --  "$*"
 345     while [ $# -gt 0 ] ; do
 346         case "$1" in
 347             -h|--help) usageversion;                        exit 0 ;;
 348             -n|--no-action) action='echo'; docmd='NO';      shift  ;;
 349             -v|--verbose) VERBOSE=1;                        shift  ;;
 350             -P|--package)
 351                 opt_package="$2";                              shift 2 ;;
 352             -s|--src-dir)
 353                 opt_source_dir="$2";                       shift 2 ;;
 354             --sum-file)
 355                 opt_old_mdsum_file="$2";                  shift 2 ;;
 356             --state-dir)
 357                 opt_state_dir="$2";                        shift 2 ;;
 358             --debconf-template)
 359                 override_template="$2";                    shift 2 ;;
 360             -D|-d|--debug|--DEBUG)
 361                 # d has an optional argument. As we are in quoted mode,
 362                 # an empty parameter will be generated if its optional
 363                 # argument is not found.
 364                 case "$2" in
 365                     "") DEBUG=$(vset 1 "The Debug value");      shift 2 ;;
 366                     *)  DEBUG=$(vset "$2" "The Debug value"); shift 2 ;;
 367                 esac ;;
 368             -p|--purge) PURGE=YES;                         shift   ;;
 369             --three-way) THREEWAY=YES;                       shift   ;;
 370             --debconf-ok) DEBCONF_OK=YES;                    shift   ;;
 371             -Z) selinux='-Z';                                shift   ;;
 372             --)  shift ; handle_file_args "$@";            return   ;;
 373             *) echo >&2 "Internal error!" ; exit 1 ;;
 374         esac
 375     done
 376 }
 377
 378 # A separate assignment is essential to ensure getopt(1) error status isn't
 379 # lost.
 380 UCF_OPTS="$(getopt -a -o hs:d::D::npP:Zv -n "$progname" \
 381                      --long help,src-dir:,sum-file:,dest-dir:,debug::,DEBUG::,no-action,package:,purge,verbose,three-way,debconf-ok,debconf-template:,state-dir: \
 382                      -- "$@")"
 383
 384 handle_opts "$UCF_OPTS"
 385
 386 ######################################################################
 387 ########                                                     #########
 388 ########              Sanity checking                        #########
 389 ########                                                     #########
 390 ######################################################################
 391 # Need to run as root, or else the
 392 if test "$(id -u)" != 0; then
 393     if [ "$docmd" = "YES" ]; then
 394         echo "$progname: Need to be run as root." >&2
 395         echo "$progname: Setting up no action mode." >&2
 396         action='echo'; docmd='NO'
 397     fi
 398 fi
 399
 400 # Follow dpkg-divert as though we are installed as part of $opt_package
 401 divert_line=$(dpkg-divert --listpackage "$dest_file")
 402 if [ -n "$divert_line" ]; then
 403    # name of the package or 'LOCAL' for a local diversion
 404    divert_package="$divert_line"
 405
 406    if [ "$divert_package" != "$opt_package" ]; then
 407        dest_file=$(dpkg-divert --truename "$dest_file")
 408    fi
 409 fi
 410 dest_file_bre="[[:space:]]$(escape_bre "$dest_file")"'$'
 411
 412 ######################################################################
 413 ########                                                     #########
 414 ########              Set Default Values                     #########
 415 ########                                                     #########
 416 ######################################################################
 417 # Load site defaults and overrides.
 418 if [ -f /etc/ucf.conf ]; then
 419     . /etc/ucf.conf
 420 fi
 421
 422 # Command line, env variable, config file, or default
 423 if [ "$opt_source_dir" ]; then
 424     source_dir=$(vset "$opt_source_dir" "The Source directory")
 425 elif [ "$UCF_SOURCE_DIR" ]; then
 426     source_dir=$(vset "$UCF_SOURCE_DIR" "The Source directory")
 427 elif [ "$conf_source_dir" ]; then
 428     source_dir=$(vset "$conf_source_dir" "The Source directory")
 429 else
 430     if [ "$new_file" ]; then
 431         source_dir=$(vset "$(dirname "$new_file")" "The Source directory")
 432     else
 433         source_dir=$(vset "/tmp" "The Source directory")
 434     fi
 435
 436 fi
 437
 438 if [ "$PAGER" ] && which "$PAGER" >/dev/null 2>&1 ; then
 439     my_pager="$(which "$PAGER")"
 440 elif [ -s /usr/bin/pager ] &&
 441      [ "$(readlink -e /usr/bin/pager || :)" ]; then
 442     my_pager=/usr/bin/pager
 443 elif [ -x /usr/bin/sensible-pager ]; then
 444     my_pager=/usr/bin/sensible-pager
 445 elif [ -x /bin/more ]; then
 446     my_pager=/bin/more
 447 else
 448     my_pager=
 449 fi
 450
 451 # Command line, env variable, config file, or default
 452 if [ "$opt_state_dir" ]; then
 453     statedir=$(vset "$opt_state_dir" "The State directory")
 454 elif [ "$UCF_STATE_DIR" ]; then
 455     statedir=$(vset "$UCF_STATE_DIR" "The State directory")
 456 elif [ "$conf_state_dir" ]; then
 457     statedir=$(vset "$conf_state_dir" "The State directory")
 458 else
 459     statedir=$(vset '/var/lib/ucf'  "The State directory")
 460 fi
 461
 462 # Handle conffold and conffnew together. See #980996
 463 # Default
 464 force_conff=
 465
 466 # Config file
 467 if [ "$conf_force_conffold" ]; then
 468     if [ "$conf_force_conffnew" ]; then
 469         echo >&2 "Error: Only one of conf_force_conffold and conf_force_conffnew should"
 470         echo >&2 "       be set in the config file"
 471         exit 1
 472     fi
 473     force_conff=$(vset "old" "Force keep file")
 474 elif [ "$conf_force_conffnew" ]; then
 475     force_conff=$(vset "new" "Force keep file")
 476 fi
 477
 478 # Environment
 479 if [ "$UCF_FORCE_CONFFOLD" ]; then
 480     if [ "$UCF_FORCE_CONFFNEW" ]; then
 481         echo >&2 "Error: Only one of UCF_FORCE_CONFFOLD and UCF_FORCE_CONFFNEW should"
 482         echo >&2 "       be set in the environment"
 483         exit 1
 484     fi
 485     force_conff=$(vset "old" "Force keep file")
 486 elif [ "$UCF_FORCE_CONFFNEW" ]; then
 487     force_conff=$(vset "new" "Force keep file")
 488 fi
 489
 490 # Env variable, config file, or default
 491 if [ "$UCF_FORCE_CONFFMISS" ]; then
 492     force_conffmiss=$(vset "$UCF_FORCE_CONFFMISS" "Replace any missing files")
 493 elif [ "$conf_force_conffmiss" ]; then
 494     force_conffmiss=$(vset "$conf_force_conffmiss" "Replace any missing files")
 495 else
 496     force_conffmiss=''
 497 fi
 498
 499 # DPKG_FORCE overrides all others: see #925375.
 500 IFS=,
 501 for f in $DPKG_FORCE ; do
 502     case $f in
 503         confmiss) force_conffmiss=$(vset 1 "DPKG_FORCE replace missing files") ;;
 504         confold) force_conff=$(vset "old" "DPKG_FORCE keep file") ;;
 505         confnew) force_conff=$(vset "new" "DPKG_FORCE keep file") ;;
 506         # The following override other settings, so break out of loop.
 507         confdef) unset force_conff
 508                  [ "$VERBOSE" ] && echo >&2 "DPKG_FORCE keep file default"
 509                  break ;;
 510         confask) force_conff=$(vset "ask" "DPKG_FORCE keep file"); break ;;
 511     esac
 512 done
 513 unset IFS
 514
 515 if [ -n "$opt_old_mdsum_file" ]; then
 516     old_mdsum_file=$(vset "$opt_old_mdsum_file" "The md5sum is found here")
 517 elif [ "$UCF_OLD_MDSUM_FILE" ]; then
 518     old_mdsum_file=$(vset "$UCF_OLD_MDSUM_FILE" "The md5sum is found here")
 519 elif [ "$conf_old_mdsum_file" ]; then
 520     old_mdsum_file=$(vset "$conf_old_mdsum_file" "Replace the old file")
 521 elif [ "${new_file}" ]; then
 522     old_mdsum_file="$source_dir/$(basename "${new_file}").md5sum"
 523 else
 524     old_mdsum_file=""
 525 fi
 526
 527 ######################################################################
 528 ########                                                     #########
 529 ########               More Sanity checking                  #########
 530 ########                                                     #########
 531 ######################################################################
 532
 533 # VERBOSE of 0 is supposed to be the same as not setting VERBOSE
 534 if [ "$VERBOSE" = "0" ]; then
 535     VERBOSE=''
 536 fi
 537
 538 if [ -e "$statedir/hashfile" ] && [ ! -w "$statedir/hashfile" ]; then
 539     echo >&2 "ucf: do not have write privilege to the state data"
 540     if [ "$docmd" = "YES" ]; then
 541         exit 1
 542     fi
 543 fi
 544
 545 if [ ! -d "$statedir/cache" ]; then
 546     $action mkdir -p "$statedir/cache"
 547 fi
 548
 549 # test and see if this file exists in the database
 550 if [ -e "$statedir/hashfile" ]; then
 551     if [ "$VERBOSE" ]; then
 552         echo >&2 "The hash file exists"
 553         echo >&2 "grep ${dest_file_bre} $statedir/hashfile"
 554         grep "${dest_file_bre}" "$statedir/hashfile" >&2 || true
 555     fi
 556     lastsum=$(grep "${dest_file_bre}" "$statedir/hashfile" | \
 557                    awk '{print $1;}' )
 558 fi
 559
 560 if [ "${new_file}" ]; then
 561     old_mdsum_dir="$source_dir/$(basename "${new_file}").md5sum.d"
 562 else
 563     old_mdsum_dir=""
 564 fi
 565
 566 cached_file="$(echo "$dest_file" | tr / :)"
 567 ######################################################################
 568 ########                                                     #########
 569 ########                  Debugging dump                     #########
 570 ########                                                     #########
 571 ######################################################################
 572
 573 if [ "$DEBUG" -gt 0 ]; then
 574     cat >&2 <<EOF
 575 The new start file is      \`$new_file\'
 576 The destination is         \`$dest_file\'  (\`$dest_file_bre\')
 577 The history is kept under  \'$source_dir\'
 578 The file may be cached at \'$statedir/cache/$cached_file\'
 579 EOF
 580     if [ -s "$dest_file" ]; then
 581         echo "The destination file exists, and has md5sum:"
 582         md5sum "$dest_file"
 583     else
 584         echo "The destination file does not exist."
 585     fi
 586     if [ "$lastsum" ]; then
 587         echo "The old md5sum exists, and is:"
 588         echo "$lastsum"
 589     else
 590         echo "The old md5sum does not exist."
 591         if [ -d "$old_mdsum_dir" ] || [ -f "$old_mdsum_file" ]; then
 592             echo "However, there are historical md5sums around."
 593         fi
 594     fi
 595     if [ -e "$new_file" ]; then
 596         echo "The new file exists, and has md5sum:"
 597         md5sum "$new_file"
 598     else
 599         echo "The new file does not exist."
 600     fi
 601     if [ -d "$old_mdsum_dir" ]; then
 602         echo "The historical md5sum dir $old_mdsum_dir exists"
 603     elif [ -f "$old_mdsum_file" ]; then
 604         echo "The historical md5sum file $old_mdsum_file exists"
 605     else
 606         echo "Historical md5sums are not available"
 607     fi
 608 fi
 609
 610 ######################################################################
 611 ########                                                     #########
 612 ########        Short circuit if we are purging              #########
 613 ########                                                     #########
 614 ######################################################################
 615
 616 if [ "$PURGE" = "YES" ]; then
 617     [ "$VERBOSE" ] &&
 618         echo >&2 "Preparing to purge ${dest_file}"
 619     purge_md5sum
 620     exit 0
 621 fi
 622
 623 ######################################################################
 624 ########                                                     #########
 625 ########                  DebConf stuff                      #########
 626 ########                                                     #########
 627 ######################################################################
 628
 629 # Is debconf already running? Kinda tricky, because it will be after the
 630 # confmodule is sourced, so only test before that.
 631 if [ -z "$DEBCONF_ALREADY_RUNNING" ]; then
 632     if [ "$DEBIAN_HAS_FRONTEND" ]; then
 633         DEBCONF_ALREADY_RUNNING='YES'
 634     else
 635         DEBCONF_ALREADY_RUNNING='NO'
 636     fi
 637 fi
 638
 639 export DEBCONF_ALREADY_RUNNING
 640
 641 if [ -z "$DEBCONF_OK" ]; then
 642     if [ "$DEBCONF_ALREADY_RUNNING" = 'YES' ]; then
 643         DEBCONF_OK='NO'
 644     else
 645         DEBCONF_OK='YES'
 646     fi
 647 fi
 648
 649 # Time to start nagging the users who call ucf without debconf-ok
 650 if [ "$DEBCONF_ALREADY_RUNNING"  = 'YES' ] && [ "$DEBCONF_OK" = NO ]; then
 651         # Commented out for now, uncomment after a while to begin nagging
 652         # maintainers to fix their scripts.
 653         cat \
 654 <<END
 655 *** WARNING: ucf was run from a maintainer script that uses debconf, but
 656              the script did not pass --debconf-ok to ucf. The maintainer
 657              script should be fixed to not stop debconf before calling ucf,
 658              and pass it this parameter. For now, ucf will revert to using
 659              old-style, non-debconf prompting. Ugh!
 660
 661              Please inform the package maintainer about this problem.
 662 END
 663 fi
 664
 665 # Start up debconf or at least get the db_* commands available
 666 # Don't check debconf with shellcheck.
 667 # shellcheck source=/dev/null
 668 if [ -e /usr/share/debconf/confmodule ]; then
 669     if test "$(id -u)" = 0; then
 670         . /usr/share/debconf/confmodule
 671
 672         # Load our templates, just in case our template has
 673         # not been loaded or the Debconf DB lost or corrupted
 674         # since then, but only if it is OK to use debconf.
 675         if [ "$DEBCONF_OK" = 'YES' ]; then
 676             db_x_loadtemplatefile "$(dpkg-query --control-path ucf templates)" ucf
 677         fi
 678     else
 679         echo >&2 "$progname: Not loading confmodule, since we are not running as root."
 680     fi
 681     # Only set the title if debconf was not already running.
 682     # If it was running, then we do not want to clobber the
 683     # title used for configuring the whole package with debconf.
 684     if [ "$DEBCONF_ALREADY_RUNNING" = 'NO' ]; then
 685         if ! db_settitle ucf/title 2>/dev/null; then
 686             # Older debconf that does not support that command.
 687             if test "$(id -u)" = 0; then
 688                 db_title "Modified configuration file"
 689             else
 690                 echo >&2 "$progname: Not changing title, since we are not running as root."
 691             fi
 692         fi
 693     fi
 694 fi
 695
 696 ######################################################################
 697 ########                                                     #########
 698 ########                Start Processing                     #########
 699 ########                                                     #########
 700 ######################################################################
 701
 702 orig_new_file="$new_file"       # Since sometimes we replace the newfile below
 703 newsum=$(md5sum "$new_file" | awk '{print $1}')
 704
 705 ######################################################################
 706 ########                                                     #########
 707 ########               Do the replacement                    #########
 708 ########                                                     #########
 709 ######################################################################
 710 # Step 1: If we have no record of this file, and dest file
 711 #         does, We need to determine how to initialize the
 712 #         ${old_mdsum_prefix}.old file..
 713 if [ -e "$dest_file" ]; then
 714     destsum=$(md5sum "$dest_file"  | awk '{print $1}')
 715     if [ ! "$lastsum" ]; then
 716 #      a: If we have a directory containing historical md5sums of this
 717 #         file in question, we should look and see if the currently
 718 #         installed file matches any of the old md5sums; in which case
 719 #         it can be silently replaced.
 720         if [ -d "$old_mdsum_dir" ] || [ -f "$old_mdsum_file" ]; then
 721             if [ -d "$old_mdsum_dir"  ]; then
 722                 for file in "${old_mdsum_dir}/"*; do
 723                     oldsum="$(awk '{print $1}' "$file")"
 724                     if [ "$oldsum" = "$destsum"  ]; then
 725                         if [ "$force_conff" != "old" ]; then
 726 #                           Bingo! replace, set the md5sum, and we are done
 727                             [ "$VERBOSE" ] &&
 728                                 echo >&2 \
 729                                     "Replacing config file $dest_file with new version"
 730                             replace_conf_file
 731                             exit 0
 732                         else
 733                             replace_md5sum
 734                             cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
 735                             exit 0
 736                         fi
 737                     fi
 738                 done
 739             elif [ -f "$old_mdsum_file" ]; then
 740                 oldsum=$(grep -E "^${destsum}" "$old_mdsum_file" || true)
 741                 if [ "$oldsum" ]; then
 742 #                    Bingo
 743                     if [ "$force_conff" != old ]; then
 744                         [ "$VERBOSE" ] &&
 745                             echo >&2 \
 746                                 "Replacing config file $dest_file with new version"
 747                         replace_conf_file
 748                         exit 0
 749                     else
 750                         replace_md5sum
 751                         cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
 752                         exit 0
 753                     fi
 754                 fi
 755             fi
 756 #          Well, nothing matched. We now check to see if the
 757 #          maintainer has an opinion on how to set the ``md5sum of the
 758 #          previously installed version'', since we have no way of
 759 #          determining that automatically. Please note that unless
 760 #          there are limited number of previously released packages
 761 #          (like just one), the maintainer is also making a guess at
 762 #          this point by supplying a historical md5sum default file.
 763             [ "$VERBOSE" ] &&
 764                 echo >&2 "Historical md5sums did not match."
 765             if [ -d "$old_mdsum_dir"  ]; then
 766                 if [ -e "${old_mdsum_dir}/default" ]; then
 767                     [ "$VERBOSE" ] &&
 768                         echo >&2 "However, a default entry exists, using it."
 769                     lastsum="$(awk '{print $1;}' "${old_mdsum_dir}"/default)"
 770                     do_replace_md5sum=1
 771                 fi
 772             elif [ -f "$old_mdsum_file" ]; then
 773                 oldsum=$(grep -E "[[:space:]]default$" "$old_mdsum_file" | \
 774                     awk '{print $1;}')
 775                 if [ "$oldsum" ]; then
 776 #                   Bingo
 777                     lastsum=$oldsum
 778                     do_replace_md5sum=1
 779                 fi
 780             fi
 781         fi
 782
 783 #       At this point, we are almost certain that either the
 784 #       historical record of md5sums is not complete, or the user has
 785 #       changed the configuration file. Rather than guessing and
 786 #       chosing one of the historical md5sums, we fall through to the
 787 #       solution used if there had been no historical md5sums
 788 #       directory/file.
 789         if [ ! "$lastsum" ]; then
 790 #       b: We do not have a historical list of md5sums, or none
 791 #          matched, and we still need to initialize the
 792 #          ${old_mdsum_prefix}.old file. We can't determine whther or
 793 #          not they made any changes, so we err on the side of caution
 794 #          and ask.
 795             [ "$VERBOSE" ] &&
 796                 echo >&2 "No match found, we shall ask."
 797             lastsum='AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
 798         fi # the old md5sum file does not exist, and the historical
 799            # record failed
 800     fi # the old md5sum file does not exist (bug))
 801 else  # "$dest_file" does not exist
 802 # Step 2: If destfile does not exist, create it, set the file
 803 #         "${old_mdsum_prefix}.old" to the md5sum of the new file, and we
 804 #         are done
 805     if [ ! "$lastsum" ]; then
 806         # Ok, so there is no indication that the package was ever
 807         # installed on this machine.
 808         echo >&2 "Creating config file $dest_file with new version"
 809         replace_conf_file
 810         exit 0
 811     elif [ "$lastsum" = "$newsum" ]; then
 812         # OK, new version of the file is the same as the last version
 813         # we saw. Since the user apparently has deleted the file,
 814         # nothing needs be done, unless we have been told differently
 815         if [ "$force_conffmiss" ]; then
 816             echo >&2 "Recreating deleted config file $dest_file with new version, as asked"
 817             replace_conf_file
 818             exit 0
 819         else
 820             echo >&2 "Not replacing deleted config file $dest_file"
 821         fi
 822
 823     else
 824         # OK. New upstream version.
 825         if [ "$force_conffmiss" ]; then
 826             # User has said to replace missing files, so we do so, no
 827             # questions asked.
 828             echo >&2 "Recreating deleted config file $dest_file with new version, as asked"
 829             replace_conf_file
 830             exit 0
 831         else
 832             # Even though the user has deleted this file, they should
 833             # be asked now, unless specified otherwise.
 834             if [ "$force_conff" != "old" ]; then
 835                 destsum='AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
 836             else
 837                 exit 0
 838             fi
 839         fi
 840     fi
 841 fi
 842
 843 # Here, the destfile exists.
 844
 845 # step 3: If the old md5sum and the md5sum of the new file
 846 #         do not match, we need to take action.
 847 if [ "$lastsum" = "$newsum" ]; then
 848     if [ "$force_conff" = 'ask' ]; then
 849         [ "$VERBOSE" ] &&
 850             echo >&2 "Forced to ask even though md5sums match."
 851         destsum='AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
 852     else
 853         [ "$VERBOSE" ] &&
 854             echo >&2 "md5sums match, nothing needs be done."
 855         if [ "$do_replace_md5sum" ]; then
 856             replace_md5sum
 857         fi
 858         exit 0;                 # Hah. Match. We are done.
 859     fi
 860 fi
 861 #      a: If the md5sum of the dest file is the same as lastsum, replace the
 862 #         destfile, saying we are replacing old config files
 863 if [ "$destsum" = "$lastsum" ]; then
 864     if [ "$force_conff" != old ]; then
 865         echo >&2 "Replacing config file $dest_file with new version"
 866         replace_conf_file
 867         exit 0
 868     else
 869         replace_md5sum
 870         cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
 871         exit 0
 872     fi
 873 else
 874 #      b: If the md5sum of the dest file differs from lastsum, we need to ask
 875 #         the user what action to take.
 876     if [ "$force_conff" = "new" ]; then
 877         echo >&2 "Replacing config file $dest_file with new version"
 878         echo >&2 "since you asked for it."
 879         if [ "$destsum" = "$newsum" ]; then
 880             echo >&2 "The new and the old files are identical, AFAICS"
 881         else
 882             echo >&2 "The new and the old files are different"
 883         fi
 884         replace_conf_file
 885         exit 0
 886     fi
 887     if [ "$force_conff" = "old" ]; then
 888         replace_md5sum
 889         cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
 890         exit 0
 891     fi
 892 #      c: If the destination file is the same as the new maintianer provided one,
 893 #         we need do nothing.
 894     if [ "$newsum" = "$destsum" ]; then
 895         [ "$VERBOSE" ] &&
 896             echo >&2 "md5sums of the file in place matches, nothing needs be done."
 897         replace_md5sum
 898         exit 0;                 # Hah. Match. We are done.
 899     fi
 900
 901     done='NO'
 902     while [ "$done" = "NO" ]; do
 903         if [ "$DEBCONF_OK" = "YES" ] && [ "$DEBIAN_HAS_FRONTEND" ]; then
 904                 # Use debconf to prompt.
 905                 if [ -e "$statedir/cache/$cached_file" ] && [ "$THREEWAY" ]; then
 906                         templ=ucf/changeprompt_threeway
 907                 else
 908                         templ=ucf/changeprompt
 909                 fi
 910                 if [ "$override_template" ]; then
 911                         choices="$(db_metaget $templ Choices-C)"
 912                         choices2="$(db_metaget "$override_template" Choices-C)"
 913                         if [ "$choices" = "$choices2" ]; then
 914                                 templ=$override_template
 915                         fi
 916                 fi
 917                 db_fset "$templ" seen false
 918                 db_reset "$templ"
 919                 db_subst "$templ" FILE "$dest_file"
 920                 db_subst "$templ" NEW  "$new_file"
 921                 db_subst "$templ" BASENAME "$(basename "$dest_file")"
 922                 db_input critical "$templ" || true
 923                 if ! db_go; then
 924                         # The current ucf interface does not provide a way for it
 925                         # to tell its caller that the user chose to back up.
 926                         # However, we could get here, if the caller turned on
 927                         # debconf's backup capb. The best thing to do seems to be
 928                         # to ignore requests to back up.
 929                         continue
 930                 fi
 931                 db_get "$templ"
 932                 ANSWER="$RET"
 933         else
 934             echo >&2 "Need debconf to interact"
 935             exit 2
 936         fi
 937
 938         case "$ANSWER" in
 939             install_new|y|Y|I|i)
 940                 echo >&2 "Replacing config file $dest_file with new version"
 941                 RETAIN_OLD=YES
 942                 replace_conf_file;
 943                 exit 0;
 944                 ;;
 945             diff|D|d)
 946                 DIFF="$(run_diff diff -uBbwt "$dest_file" "$new_file")"
 947                 show_diff "$DIFF"
 948                 ;;
 949             sdiff|S|s)
 950                 DIFF="$(run_diff sdiff -BbWt "$dest_file" "$new_file")"
 951                 show_diff "$DIFF"
 952                 ;;
 953             diff_threeway|3|t|T)
 954                 if [ -e "$statedir/cache/$cached_file" ] && \
 955                     [ "$THREEWAY" ]; then
 956                     if [ -e "$dest_file" ]; then
 957                         DIFF="$(diff3 -L Current -L Older -L New -A \
 958                             "$dest_file" "$statedir/cache/$cached_file" \
 959                             "$new_file")"  || true
 960                     else
 961                         DIFF="$(diff3 -L Current -L Older -L New -A \
 962                             /dev/null "$statedir/cache/$cached_file" \
 963                             "$new_file")"  || true
 964                     fi
 965                     show_diff "$DIFF"
 966                 else
 967                     DIFF="$(run_diff diff -uBbwt "$dest_file" "$new_file")"
 968                     show_diff "$DIFF"
 969                 fi
 970                 ;;
 971             merge_threeway|M|m)
 972                 echo >&2 "Merging changes into the new version"
 973                 if [ -e "$statedir/cache/$cached_file" ] && \
 974                        [ "$THREEWAY" ]; then
 975                     ret=0
 976                     diff3 -L Current -L Older -L New -m \
 977                         "$dest_file" "$statedir/cache/$cached_file" \
 978                         "$new_file" > "$dest_file.${NEW_SUFFIX}" || ret=$?
 979                     case "$ret" in
 980                         0)
 981                             new_file="$dest_file.${NEW_SUFFIX}"
 982                             RETAIN_OLD=YES
 983                             replace_conf_file
 984                             rm -f "$dest_file.${NEW_SUFFIX}" # don't need this around no mo'
 985                             exit 0
 986                             ;;
 987                         *)
 988                             mv "$dest_file.${NEW_SUFFIX}" "$dest_file.${ERR_SUFFIX}"
 989                             db_subst ucf/conflicts_found dest_file "$dest_file"
 990                             db_subst ucf/conflicts_found ERR_SUFFIX "${ERR_SUFFIX}"
 991                             db_input critical ucf/conflicts_found || true
 992                             db_go || true
 993                             ;;
 994                     esac
 995                 else
 996                     replace_conf_file
 997                     rm -f "$dest_file.${NEW_SUFFIX}" # don't need this around no mo'
 998                     exit 0
 999                 fi
1000                 ;;
1001             shell|Z|z)
1002                 # We explicitly connect STDIN and STDOUT to the
1003                 # script's controlling terminal, so even if STDIN is
1004                 # fed by a pipe, as is the case when run from
1005                 # /usr/bin/debconf, the shell should be fully
1006                 # functional. However, the test for a controlling
1007                 # terminal uses /usr/bin/tty, which consults only
1008                 # STDIN. As far as I can tell, when run from debconf,
1009                 # ucf will _never_ use the current terminal. If the
1010                 # goal is to check for access to a terminal, the test
1011                 # should be for foreground process group membership,
1012                 # not a terminal connected to STDIN (tty -s), and not
1013                 # a terminal it doesn't necessarily own (tty -s
1014                 # </dev/tty). The easiest way do this from a shell is
1015                 # probably with /bin/ps.
1016                 if [ "$(ps -o tpgid= $$)" -eq "$(ps -o pgid= $$)" ]; then
1017                     export UCF_CONFFILE_OLD="$dest_file"
1018                     export UCF_CONFFILE_NEW="$new_file"
1019                     bash >/dev/tty </dev/tty || true
1020                 elif [ -n "$DISPLAY" ]; then
1021                     x-terminal-emulator || true
1022                 else
1023                     # Don't know what to do
1024                     echo >&2 "No terminal, and no DISPLAY set, can't fork shell."
1025                     sleep 3
1026                 fi
1027                 ;;
1028             keep_current|n|N|o|O|'')
1029                 replace_md5sum
1030
1031                 cp -pf "$orig_new_file" "$dest_file.${DIST_SUFFIX}"
1032                 exit 0
1033                 ;;
1034             *)
1035                 if [ "$DEBCONF_OK" = "YES" ]; then
1036                         echo "Error: unknown response from debconf:'$RET'" >&2
1037                         exit 1
1038                 else
1039                         echo
1040                         echo "Please answer with one of the single letters listed." >&2
1041                         echo
1042                 fi
1043         esac
1044     done
1045 fi
1046
1047 db_stop
1048
1049 exit 0