making a .dot (graphviz) graph of RPM dependencies

http://www.singularity.be/2008/07/making-dot-graphviz-graph-of-rpm.html

nice tool for making .dot graphs with RPM dependecies on installed system:

#!/bin/bash

# deps:
#    bash
#    rpm
#    sed
#    cut
#    uniq
#    sort

installedrpms=$(rpm -qa --queryformat "%{NAME}\n")


function printdeps() {
  local package deps dep providedby out

  package=$1
  out=""
  deps=$(rpm -qR $package | cut -d " " -f 1)

  for dep in $deps;
  do
      providedby=$(rpm -q --queryformat "%{NAME}\n" --whatprovides "$dep")
      if [ $? -eq 0 ];
      then
          # packages should not depend on themselves
          if [ "$package" != "$providedby" ];
          then
              out="$out\"$package\" -> \"$providedby\";\n"
          fi
      fi
  done

  echo $out
}

alloutput=""

for i in $installedrpms;
do
  output=$(printdeps $i)
  alloutput="$alloutput$output"
done


echo "digraph deptree {"
echo -e "$alloutput" | sort | uniq
echo "}"