pkg-md5-sums (draft)

#!/bin/bash

directories=( "/var/packages/" "/var/packages/builtin_files" "/var/lib/dpkg" )
outfile=../data-generators/pkg_md5_sums
CWD="$PWD"

RP_FN="`which realpath`"
function realpath(){
    case "$RP_TARGET" in
    *busybox*)
      if [ "$1" = -m ]; then
        shift
        A_PATH=$1
        A_PATH=$(echo "$A_path" | sed 's#^./#'"$CWD"'#g' )
        A_PATH=$(echo "$A_path" | sed 's#^../#'"$CWD"'#g' ) && A_PATH=$(dirname $A_PATH)
        echo "Warning simulating '-m' option since xzit isn't supported by busybox" >2
        echo "A_PATH=$A_PATH" >2
        if [ -f  "$A_PATH" ] || [ -d  "$A_PATH" ]; then
          $RP_FN "$@"
        else
          echo "$A_PATH"
        fi
      else
        $RP_FN "$@"
      fi
      ;;
    *)
      $RP_FN "$@"
      ;;
    esac
}
export -f realpath
outfile=$(realpath -m "$outfile")

AWK_fn='
/^Package:/     { sub(/^Package: /,"");  PKG=$0; }
/^Version:/     { sub(/^Version: /,"");  PKGVER=$0; }
/^Filename:/    { sub(/^Filename: /,""); PKGPATH=$0; sub(/.*\//,""); PKGFILE=$0; }


/^$/            { print PKG "|" PKGVER "|" PKGFILE "|" "dpkg";
                  PKG=""; PKGVER=""; PKGFILE=""; PKGPATH=""; PKGPRIO=""; PKGSECTION=""; PKGMD5="";  PKGDEP=""; }
'


[ -f "outfile" ] && rm "$outfile"
touch "$outfile"
[ -f "outfile"_md5 ] && rm "$outfile"_md5
touch "$outfile"_md5
[ -f "outfile"_db ] && rm "$outfile"_db
touch "$outfile"_db

for a_dir in "${directories[@]}"; do
  bname="$(basename "$a_dir")"
  case "$bname" in
  packages)
    md5sum "$a_dir" | sed -r '/glibc .*/ {s#(glibc6) (.*)#libc6 \2#;n}; /.*/ {s#([^[:blank:]]*)(\.files) (.*)#\1 \1\2 \3#g'| tr ' ' '|' \
         | sed -r 's#$#|'"$bname"'#g' | sort >> "$outfile"_md5
    #f2=pkg(?version), f3=version, f8=filename
    cut -f2,3,8 -d' ' --output-delimiter="|" "a_dir"/user-installed-packages | sed -r 's#^(.*\|)([^|]+\|)(.[a-z]+\|)(.*$)#\2\1\2\3\4#g' | sort >> "$outfile"_db
    join -j 1 "$out_file"_md5 >> "$out_file"
    ;;
  builtin_files)
    md5sum "$a_dir" | sed -r '/glibc .*/ {s#(glibc6) (.*)#libc6 \2#;n}; /.*/ {s#([^[:blank:]]*) (.*)#\1 \1\2#g'| tr ' ' '|' \
        sed -r 's#$#|'"$bname"'#g' -e | sort >> "$out_file"_md5
    cut -f2,3,8 -d' ' --output-delimiter="|" "a_dir"/user-installed-packages | sort >> "$out_file"_packages_db
    join -j 1 "$out_file"_packages >> "$out_file"
    ;;
  #dpkg)
  #  md5sum "$a_dir" | sed -r 's#$#|'"$bname"'#g' | sort > "$out_file"_dpkg
  #  ;;
  esac
done