apt/cmdline/apt-cache.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: apt-cache.cc,v 1.72 2004/04/30 04:34:03 mdz Exp $
/* ######################################################################
   
   apt-cache - Manages the cache files
   
   apt-cache provides some functions fo manipulating the cache files.
   It uses the command line interface common to all the APT tools. 
   
   Returns 100 on failure, 0 on success.
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#include<config.h>

#include <apt-pkg/algorithms.h>
#include <apt-pkg/cachefile.h>
#include <apt-pkg/cacheset.h>
#include <apt-pkg/cmndline.h>
#include <apt-pkg/error.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/indexfile.h>
#include <apt-pkg/init.h>
#include <apt-pkg/metaindex.h>
#include <apt-pkg/pkgrecords.h>
#include <apt-pkg/pkgsystem.h>
#include <apt-pkg/policy.h>
#include <apt-pkg/progress.h>
#include <apt-pkg/sourcelist.h>
#include <apt-pkg/sptr.h>
#include <apt-pkg/srcrecords.h>
#include <apt-pkg/strutl.h>
#include <apt-pkg/tagfile.h>
#include <apt-pkg/version.h>
#include <apt-pkg/cacheiterators.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/depcache.h>
#include <apt-pkg/macros.h>
#include <apt-pkg/mmap.h>
#include <apt-pkg/pkgcache.h>

#include <apt-private/private-cacheset.h>
#include <apt-private/private-cmndline.h>

#include <regex.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <set>
#include <string>
#include <vector>

#include <apti18n.h>
									/*}}}*/

using namespace std;

// LocalitySort - Sort a version list by package file locality		/*{{{*/
// ---------------------------------------------------------------------
/* */
static int LocalityCompare(const void *a, const void *b)
{
   pkgCache::VerFile *A = *(pkgCache::VerFile **)a;
   pkgCache::VerFile *B = *(pkgCache::VerFile **)b;
   
   if (A == 0 && B == 0)
      return 0;
   if (A == 0)
      return 1;
   if (B == 0)
      return -1;
   
   if (A->File == B->File)
      return A->Offset - B->Offset;
   return A->File - B->File;
}

static void LocalitySort(pkgCache::VerFile **begin,
		  unsigned long Count,size_t Size)
{   
   qsort(begin,Count,Size,LocalityCompare);
}

static void LocalitySort(pkgCache::DescFile **begin,
		  unsigned long Count,size_t Size)
{   
   qsort(begin,Count,Size,LocalityCompare);
}
									/*}}}*/
// UnMet - Show unmet dependencies					/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool ShowUnMet(pkgCache::VerIterator const &V, bool const Important)
{
	 bool Header = false;
	 for (pkgCache::DepIterator D = V.DependsList(); D.end() == false;)
	 {
	    // Collect or groups
	    pkgCache::DepIterator Start;
	    pkgCache::DepIterator End;
	    D.GlobOr(Start,End);

	    // Important deps only
	    if (Important == true)
	       if (End->Type != pkgCache::Dep::PreDepends &&
	           End->Type != pkgCache::Dep::Depends)
		  continue;

	    // Skip conflicts and replaces
	    if (End.IsNegative() == true)
	       continue;

	    // Verify the or group
	    bool OK = false;
	    pkgCache::DepIterator RealStart = Start;
	    do
	    {
	       // See if this dep is Ok
	       pkgCache::Version **VList = Start.AllTargets();
	       if (*VList != 0)
	       {
		  OK = true;
		  delete [] VList;
		  break;
	       }
	       delete [] VList;
	       
	       if (Start == End)
		  break;
	       ++Start;
	    }
	    while (1);

	    // The group is OK
	    if (OK == true)
	       continue;
	    
	    // Oops, it failed..
	    if (Header == false)
	       ioprintf(cout,_("Package %s version %s has an unmet dep:\n"),
			V.ParentPkg().FullName(true).c_str(),V.VerStr());
	    Header = true;
	    
	    // Print out the dep type
	    cout << " " << End.DepType() << ": ";

	    // Show the group
	    Start = RealStart;
	    do
	    {
	       cout << Start.TargetPkg().FullName(true);
	       if (Start.TargetVer() != 0)
		  cout << " (" << Start.CompType() << " " << Start.TargetVer() <<
		  ")";
	       if (Start == End)
		  break;
	       cout << " | ";
	       ++Start;
	    }
	    while (1);
	    
	    cout << endl;
	 }
   return true;
}
static bool UnMet(CommandLine &CmdL)
{
   bool const Important = _config->FindB("APT::Cache::Important",false);

   pkgCacheFile CacheFile;
   if (unlikely(CacheFile.GetPkgCache() == NULL))
      return false;

   if (CmdL.FileSize() <= 1)
   {
      for (pkgCache::PkgIterator P = CacheFile.GetPkgCache()->PkgBegin(); P.end() == false; ++P)
	 for (pkgCache::VerIterator V = P.VersionList(); V.end() == false; ++V)
	    if (ShowUnMet(V, Important) == false)
	       return false;
   }
   else
   {
      CacheSetHelperVirtuals helper(true, GlobalError::NOTICE);
      APT::VersionList verset = APT::VersionList::FromCommandLine(CacheFile, CmdL.FileList + 1,
				APT::CacheSetHelper::CANDIDATE, helper);
      for (APT::VersionList::iterator V = verset.begin(); V != verset.end(); ++V)
	 if (ShowUnMet(V, Important) == false)
	    return false;
   }
   return true;
}
									/*}}}*/
// DumpPackage - Show a dump of a package record			/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool DumpPackage(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   APT::CacheSetHelper helper(true, GlobalError::NOTICE);
   APT::PackageList pkgset = APT::PackageList::FromCommandLine(CacheFile, CmdL.FileList + 1, helper);

   for (APT::PackageList::const_iterator Pkg = pkgset.begin(); Pkg != pkgset.end(); ++Pkg)
   {
      cout << "Package: " << Pkg.FullName(true) << endl;
      cout << "Versions: " << endl;
      for (pkgCache::VerIterator Cur = Pkg.VersionList(); Cur.end() != true; ++Cur)
      {
	 cout << Cur.VerStr();
	 for (pkgCache::VerFileIterator Vf = Cur.FileList(); Vf.end() == false; ++Vf)
	    cout << " (" << Vf.File().FileName() << ")";
	 cout << endl;
	 for (pkgCache::DescIterator D = Cur.DescriptionList(); D.end() == false; ++D)
	 {
	    cout << " Description Language: " << D.LanguageCode() << endl
		 << "                 File: " << D.FileList().File().FileName() << endl
		 << "                  MD5: " << D.md5() << endl;
	 }
	 cout << endl;
      }
      
      cout << endl;
      
      cout << "Reverse Depends: " << endl;
      for (pkgCache::DepIterator D = Pkg.RevDependsList(); D.end() != true; ++D)
      {
	 cout << "  " << D.ParentPkg().FullName(true) << ',' << D.TargetPkg().FullName(true);
	 if (D->Version != 0)
	    cout << ' ' << DeNull(D.TargetVer()) << endl;
	 else
	    cout << endl;
      }
      
      cout << "Dependencies: " << endl;
      for (pkgCache::VerIterator Cur = Pkg.VersionList(); Cur.end() != true; ++Cur)
      {
	 cout << Cur.VerStr() << " - ";
	 for (pkgCache::DepIterator Dep = Cur.DependsList(); Dep.end() != true; ++Dep)
	    cout << Dep.TargetPkg().FullName(true) << " (" << (int)Dep->CompareOp << " " << DeNull(Dep.TargetVer()) << ") ";
	 cout << endl;
      }      

      cout << "Provides: " << endl;
      for (pkgCache::VerIterator Cur = Pkg.VersionList(); Cur.end() != true; ++Cur)
      {
	 cout << Cur.VerStr() << " - ";
	 for (pkgCache::PrvIterator Prv = Cur.ProvidesList(); Prv.end() != true; ++Prv)
	    cout << Prv.ParentPkg().FullName(true) << " ";
	 cout << endl;
      }
      cout << "Reverse Provides: " << endl;
      for (pkgCache::PrvIterator Prv = Pkg.ProvidesList(); Prv.end() != true; ++Prv)
	 cout << Prv.OwnerPkg().FullName(true) << " " << Prv.OwnerVer().VerStr() << endl;
   }

   return true;
}
									/*}}}*/
// ShowHashTableStats - Show stats about a hashtable			/*{{{*/
// ---------------------------------------------------------------------
/* */
template<class T>
static void ShowHashTableStats(std::string Type,
                               T *StartP,
                               map_pointer_t *Hashtable,
                               unsigned long Size)
{
   // hashtable stats for the HashTable
   unsigned long NumBuckets = Size;
   unsigned long UsedBuckets = 0;
   unsigned long UnusedBuckets = 0;
   unsigned long LongestBucket = 0;
   unsigned long ShortestBucket = NumBuckets;
   unsigned long Entries = 0;
   for (unsigned int i=0; i < NumBuckets; ++i)
   {
      T *P = StartP + Hashtable[i];
      if(P == 0 || P == StartP)
      {
         ++UnusedBuckets;
         continue;
      }
      ++UsedBuckets;
      unsigned long ThisBucketSize = 0;
      for (; P != StartP; P = StartP + P->Next)
         ++ThisBucketSize;
      Entries += ThisBucketSize;
      LongestBucket = std::max(ThisBucketSize, LongestBucket);
      ShortestBucket = std::min(ThisBucketSize, ShortestBucket);
   }
   cout << "Total buckets in " << Type << ": " << NumBuckets << std::endl;
   cout << "  Unused: " << UnusedBuckets << std::endl;
   cout << "  Used: " << UsedBuckets  << std::endl;
   cout << "  Average entries: " << Entries/(double)NumBuckets << std::endl;
   cout << "  Longest: " << LongestBucket << std::endl;
   cout << "  Shortest: " << ShortestBucket << std::endl;
}
									/*}}}*/
// Stats - Dump some nice statistics					/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool Stats(CommandLine &)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   cout << _("Total package names: ") << Cache->Head().GroupCount << " (" <<
      SizeToStr(Cache->Head().GroupCount*Cache->Head().GroupSz) << ')' << endl
        << _("Total package structures: ") << Cache->Head().PackageCount << " (" <<
      SizeToStr(Cache->Head().PackageCount*Cache->Head().PackageSz) << ')' << endl;

   int Normal = 0;
   int Virtual = 0;
   int NVirt = 0;
   int DVirt = 0;
   int Missing = 0;
   pkgCache::PkgIterator I = Cache->PkgBegin();
   for (;I.end() != true; ++I)
   {
      if (I->VersionList != 0 && I->ProvidesList == 0)
      {
	 Normal++;
	 continue;
      }

      if (I->VersionList != 0 && I->ProvidesList != 0)
      {
	 NVirt++;
	 continue;
      }
      
      if (I->VersionList == 0 && I->ProvidesList != 0)
      {
	 // Only 1 provides
	 if (I.ProvidesList()->NextProvides == 0)
	 {
	    DVirt++;
	 }
	 else
	    Virtual++;
	 continue;
      }
      if (I->VersionList == 0 && I->ProvidesList == 0)
      {
	 Missing++;
	 continue;
      }
   }
   cout << _("  Normal packages: ") << Normal << endl;
   cout << _("  Pure virtual packages: ") << Virtual << endl;
   cout << _("  Single virtual packages: ") << DVirt << endl;
   cout << _("  Mixed virtual packages: ") << NVirt << endl;
   cout << _("  Missing: ") << Missing << endl;
   
   cout << _("Total distinct versions: ") << Cache->Head().VersionCount << " (" <<
      SizeToStr(Cache->Head().VersionCount*Cache->Head().VersionSz) << ')' << endl;
   cout << _("Total distinct descriptions: ") << Cache->Head().DescriptionCount << " (" <<
      SizeToStr(Cache->Head().DescriptionCount*Cache->Head().DescriptionSz) << ')' << endl;
   cout << _("Total dependencies: ") << Cache->Head().DependsCount << " (" << 
      SizeToStr(Cache->Head().DependsCount*Cache->Head().DependencySz) << ')' << endl;
   
   cout << _("Total ver/file relations: ") << Cache->Head().VerFileCount << " (" <<
      SizeToStr(Cache->Head().VerFileCount*Cache->Head().VerFileSz) << ')' << endl;
   cout << _("Total Desc/File relations: ") << Cache->Head().DescFileCount << " (" <<
      SizeToStr(Cache->Head().DescFileCount*Cache->Head().DescFileSz) << ')' << endl;
   cout << _("Total Provides mappings: ") << Cache->Head().ProvidesCount << " (" <<
      SizeToStr(Cache->Head().ProvidesCount*Cache->Head().ProvidesSz) << ')' << endl;

   // String list stats
   std::set<map_stringitem_t> stritems;
   for (pkgCache::GrpIterator G = Cache->GrpBegin(); G.end() == false; ++G)
      stritems.insert(G->Name);
   for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
   {
      stritems.insert(P->Arch);
      for (pkgCache::VerIterator V = P.VersionList(); V.end() == false; ++V)
      {
	 if (V->VerStr != 0)
	    stritems.insert(V->VerStr);
	 if (V->Section != 0)
	    stritems.insert(V->Section);
#if APT_PKG_ABI >= 413
	 stritems.insert(V->SourcePkgName);
	 stritems.insert(V->SourceVerStr);
#endif
	 for (pkgCache::DepIterator D = V.DependsList(); D.end() == false; ++D)
	 {
	    if (D->Version != 0)
	       stritems.insert(D->Version);
	 }
	 for (pkgCache::DescIterator D = V.DescriptionList(); D.end() == false; ++D)
	 {
	    stritems.insert(D->md5sum);
	    stritems.insert(D->language_code);
	 }
      }
      for (pkgCache::PrvIterator Prv = P.ProvidesList(); Prv.end() == false; ++Prv)
      {
	 if (Prv->ProvideVersion != 0)
	    stritems.insert(Prv->ProvideVersion);
      }
   }
   for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
   {
      stritems.insert(F->FileName);
      stritems.insert(F->Archive);
      stritems.insert(F->Codename);
      stritems.insert(F->Component);
      stritems.insert(F->Version);
      stritems.insert(F->Origin);
      stritems.insert(F->Label);
      stritems.insert(F->Architecture);
      stritems.insert(F->Site);
      stritems.insert(F->IndexType);
   }
   unsigned long Size = 0;
   for (std::set<map_stringitem_t>::const_iterator i = stritems.begin(); i != stritems.end(); ++i)
      Size += strlen(Cache->StrP + *i) + 1;

   cout << _("Total globbed strings: ") << stritems.size() << " (" << SizeToStr(Size) << ')' << endl;
   stritems.clear();

   unsigned long Slack = 0;
   for (int I = 0; I != 7; I++)
      Slack += Cache->Head().Pools[I].ItemSize*Cache->Head().Pools[I].Count;
   cout << _("Total slack space: ") << SizeToStr(Slack) << endl;

   unsigned long Total = 0;
#define APT_CACHESIZE(X,Y) (Cache->Head().X * Cache->Head().Y)
   Total = Slack + Size +
      APT_CACHESIZE(GroupCount, GroupSz) +
      APT_CACHESIZE(PackageCount, PackageSz) +
      APT_CACHESIZE(VersionCount, VersionSz) +
      APT_CACHESIZE(DescriptionCount, DescriptionSz) +
      APT_CACHESIZE(DependsCount, DependencySz) +
      APT_CACHESIZE(PackageFileCount, PackageFileSz) +
      APT_CACHESIZE(VerFileCount, VerFileSz) +
      APT_CACHESIZE(DescFileCount, DescFileSz) +
      APT_CACHESIZE(ProvidesCount, ProvidesSz) +
      (2 * Cache->Head().HashTableSize * sizeof(map_id_t));
   cout << _("Total space accounted for: ") << SizeToStr(Total) << endl;
#undef APT_CACHESIZE

   // hashtable stats
   ShowHashTableStats<pkgCache::Package>("PkgHashTable", Cache->PkgP, Cache->Head().PkgHashTable(), Cache->Head().HashTableSize);
   ShowHashTableStats<pkgCache::Group>("GrpHashTable", Cache->GrpP, Cache->Head().GrpHashTable(), Cache->Head().HashTableSize);

   return true;
}
									/*}}}*/
// Dump - show everything						/*{{{*/
// ---------------------------------------------------------------------
/* This is worthless except fer debugging things */
static bool Dump(CommandLine &)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   std::cout << "Using Versioning System: " << Cache->VS->Label << std::endl;
   
   for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
   {
      std::cout << "Package: " << P.FullName(true) << std::endl;
      for (pkgCache::VerIterator V = P.VersionList(); V.end() == false; ++V)
      {
	 std::cout << " Version: " << V.VerStr() << std::endl;
	 std::cout << "     File: " << V.FileList().File().FileName() << std::endl;
	 for (pkgCache::DepIterator D = V.DependsList(); D.end() == false; ++D)
	    std::cout << "  Depends: " << D.TargetPkg().FullName(true) << ' ' << 
	                     DeNull(D.TargetVer()) << std::endl;
	 for (pkgCache::DescIterator D = V.DescriptionList(); D.end() == false; ++D)
	 {
	    std::cout << " Description Language: " << D.LanguageCode() << std::endl
		 << "                 File: " << D.FileList().File().FileName() << std::endl
		 << "                  MD5: " << D.md5() << std::endl;
	 } 
      }      
   }

   for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F.end() == false; ++F)
   {
      std::cout << "File: " << F.FileName() << std::endl;
      std::cout << " Type: " << F.IndexType() << std::endl;
      std::cout << " Size: " << F->Size << std::endl;
      std::cout << " ID: " << F->ID << std::endl;
      std::cout << " Flags: " << F->Flags << std::endl;
      std::cout << " Time: " << TimeRFC1123(F->mtime) << std::endl;
      std::cout << " Archive: " << DeNull(F.Archive()) << std::endl;
      std::cout << " Component: " << DeNull(F.Component()) << std::endl;
      std::cout << " Version: " << DeNull(F.Version()) << std::endl;
      std::cout << " Origin: " << DeNull(F.Origin()) << std::endl;
      std::cout << " Site: " << DeNull(F.Site()) << std::endl;
      std::cout << " Label: " << DeNull(F.Label()) << std::endl;
      std::cout << " Architecture: " << DeNull(F.Architecture()) << std::endl;
   }

   return true;
}
									/*}}}*/
// DumpAvail - Print out the available list				/*{{{*/
// ---------------------------------------------------------------------
/* This is needed to make dpkg --merge happy.. I spent a bit of time to 
   make this run really fast, perhaps I went a little overboard.. */
static bool DumpAvail(CommandLine &)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL || CacheFile.BuildPolicy() == false))
      return false;

   unsigned long Count = Cache->HeaderP->PackageCount+1;
   pkgCache::VerFile **VFList = new pkgCache::VerFile *[Count];
   memset(VFList,0,sizeof(*VFList)*Count);
   
   // Map versions that we want to write out onto the VerList array.
   for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
   {    
      if (P->VersionList == 0)
	 continue;
      
      /* Find the proper version to use. If the policy says there are no
         possible selections we return the installed version, if available..
       	 This prevents dselect from making it obsolete. */
      pkgCache::VerIterator V = CacheFile.GetPolicy()->GetCandidateVer(P);
      if (V.end() == true)
      {
	 if (P->CurrentVer == 0)
	    continue;
	 V = P.CurrentVer();
      }
      
      pkgCache::VerFileIterator VF = V.FileList();
      for (; VF.end() == false ; ++VF)
	 if ((VF.File()->Flags & pkgCache::Flag::NotSource) == 0)
	    break;
      
      /* Okay, here we have a bit of a problem.. The policy has selected the
         currently installed package - however it only exists in the
       	 status file.. We need to write out something or dselect will mark
         the package as obsolete! Thus we emit the status file entry, but
         below we remove the status line to make it valid for the 
         available file. However! We only do this if their do exist *any*
         non-source versions of the package - that way the dselect obsolete
         handling works OK. */
      if (VF.end() == true)
      {
	 for (pkgCache::VerIterator Cur = P.VersionList(); Cur.end() != true; ++Cur)
	 {
	    for (VF = Cur.FileList(); VF.end() == false; ++VF)
	    {	 
	       if ((VF.File()->Flags & pkgCache::Flag::NotSource) == 0)
	       {
		  VF = V.FileList();
		  break;
	       }
	    }
	    
	    if (VF.end() == false)
	       break;
	 }
      }
      
      VFList[P->ID] = VF;
   }
   
   LocalitySort(VFList,Count,sizeof(*VFList));

   // Iterate over all the package files and write them out.
   char *Buffer = new char[Cache->HeaderP->MaxVerFileSize+10];
   for (pkgCache::VerFile **J = VFList; *J != 0;)
   {
      pkgCache::PkgFileIterator File(*Cache,(*J)->File + Cache->PkgFileP);
      if (File.IsOk() == false)
      {
	 _error->Error(_("Package file %s is out of sync."),File.FileName());
	 break;
      }

      FileFd PkgF(File.FileName(),FileFd::ReadOnly, FileFd::Extension);
      if (_error->PendingError() == true)
	 break;
      
      /* Write all of the records from this package file, since we
       	 already did locality sorting we can now just seek through the
       	 file in read order. We apply 1 more optimization here, since often
       	 there will be < 1 byte gaps between records (for the \n) we read that
       	 into the next buffer and offset a bit.. */
      unsigned long Pos = 0;
      for (; *J != 0; J++)
      {
	 if ((*J)->File + Cache->PkgFileP != File)
	    break;
	 
	 const pkgCache::VerFile &VF = **J;

	 // Read the record and then write it out again.
	 unsigned long Jitter = VF.Offset - Pos;
	 if (Jitter > 8)
	 {
	    if (PkgF.Seek(VF.Offset) == false)
	       break;
	    Jitter = 0;
	 }
	 
	 if (PkgF.Read(Buffer,VF.Size + Jitter) == false)
	    break;
	 Buffer[VF.Size + Jitter] = '\n';
	 
	 // See above..
	 if ((File->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource)
	 {
	    pkgTagSection Tags;
	    TFRewriteData RW[] = {{"Status", NULL, NULL},{"Config-Version", NULL, NULL},{NULL, NULL, NULL}};
	    const char *Zero = 0;
	    if (Tags.Scan(Buffer+Jitter,VF.Size+1) == false ||
		TFRewrite(stdout,Tags,&Zero,RW) == false)
	    {
	       _error->Error("Internal Error, Unable to parse a package record");
	       break;
	    }
	    fputc('\n',stdout);
	 }
	 else
	 {
	    if (fwrite(Buffer+Jitter,VF.Size+1,1,stdout) != 1)
	       break;
	 }
	 
	 Pos = VF.Offset + VF.Size;
      }

      fflush(stdout);
      if (_error->PendingError() == true)
         break;
   }
   
   delete [] Buffer;
   delete [] VFList;
   return !_error->PendingError();
}
									/*}}}*/
// ShowDepends - Helper for printing out a dependency tree		/*{{{*/
static bool ShowDepends(CommandLine &CmdL, bool const RevDepends)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   CacheSetHelperVirtuals helper(false);
   APT::VersionList verset = APT::VersionList::FromCommandLine(CacheFile, CmdL.FileList + 1, APT::CacheSetHelper::CANDIDATE, helper);
   if (verset.empty() == true && helper.virtualPkgs.empty() == true)
      return _error->Error(_("No packages found"));
   std::vector<bool> Shown(Cache->Head().PackageCount);

   bool const Recurse = _config->FindB("APT::Cache::RecurseDepends", false);
   bool const Installed = _config->FindB("APT::Cache::Installed", false);
   bool const Important = _config->FindB("APT::Cache::Important", false);
   bool const ShowDepType = _config->FindB("APT::Cache::ShowDependencyType", RevDepends == false);
   bool const ShowVersion = _config->FindB("APT::Cache::ShowVersion", false);
   bool const ShowPreDepends = _config->FindB("APT::Cache::ShowPre-Depends", true);
   bool const ShowDepends = _config->FindB("APT::Cache::ShowDepends", true);
   bool const ShowRecommends = _config->FindB("APT::Cache::ShowRecommends", Important == false);
   bool const ShowSuggests = _config->FindB("APT::Cache::ShowSuggests", Important == false);
   bool const ShowReplaces = _config->FindB("APT::Cache::ShowReplaces", Important == false);
   bool const ShowConflicts = _config->FindB("APT::Cache::ShowConflicts", Important == false);
   bool const ShowBreaks = _config->FindB("APT::Cache::ShowBreaks", Important == false);
   bool const ShowEnhances = _config->FindB("APT::Cache::ShowEnhances", Important == false);
   bool const ShowOnlyFirstOr = _config->FindB("APT::Cache::ShowOnlyFirstOr", false);

   while (verset.empty() != true)
   {
      pkgCache::VerIterator Ver = *verset.begin();
      verset.erase(verset.begin());
      pkgCache::PkgIterator Pkg = Ver.ParentPkg();
      Shown[Pkg->ID] = true;

	 cout << Pkg.FullName(true) << endl;

	 if (RevDepends == true)
	    cout << "Reverse Depends:" << endl;
	 for (pkgCache::DepIterator D = RevDepends ? Pkg.RevDependsList() : Ver.DependsList();
	      D.end() == false; ++D)
	 {
	    switch (D->Type) {
	    case pkgCache::Dep::PreDepends: if (!ShowPreDepends) continue; break;
	    case pkgCache::Dep::Depends: if (!ShowDepends) continue; break;
	    case pkgCache::Dep::Recommends: if (!ShowRecommends) continue; break;
	    case pkgCache::Dep::Suggests: if (!ShowSuggests) continue; break;
	    case pkgCache::Dep::Replaces: if (!ShowReplaces) continue; break;	    case pkgCache::Dep::Conflicts: if (!ShowConflicts) continue; break;
	    case pkgCache::Dep::DpkgBreaks: if (!ShowBreaks) continue; break;
	    case pkgCache::Dep::Enhances: if (!ShowEnhances) continue; break;
	    }

	    pkgCache::PkgIterator Trg = RevDepends ? D.ParentPkg() : D.TargetPkg();

	    if((Installed && Trg->CurrentVer != 0) || !Installed)
	      {

		if ((D->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or && ShowOnlyFirstOr == false)
		  cout << " |";
		else
		  cout << "  ";
	    
		// Show the package
		if (ShowDepType == true)
		  cout << D.DepType() << ": ";
		if (Trg->VersionList == 0)
		  cout << "<" << Trg.FullName(true) << ">";
		else
		  cout << Trg.FullName(true);
		if (ShowVersion == true && D->Version != 0)
		   cout << " (" << pkgCache::CompTypeDeb(D->CompareOp) << ' ' << D.TargetVer() << ')';
		cout << std::endl;

		if (Recurse == true && Shown[Trg->ID] == false)
		{
		  Shown[Trg->ID] = true;
		  verset.insert(APT::VersionSet::FromPackage(CacheFile, Trg, APT::CacheSetHelper::CANDIDATE, helper));
		}

	      }
	    
	    // Display all solutions
	    SPtrArray<pkgCache::Version *> List = D.AllTargets();
	    pkgPrioSortList(*Cache,List);
	    for (pkgCache::Version **I = List; *I != 0; I++)
	    {
	       pkgCache::VerIterator V(*Cache,*I);
	       if (V != Cache->VerP + V.ParentPkg()->VersionList ||
		   V->ParentPkg == D->Package)
		  continue;
	       cout << "    " << V.ParentPkg().FullName(true) << endl;

		if (Recurse == true && Shown[V.ParentPkg()->ID] == false)
		{
		  Shown[V.ParentPkg()->ID] = true;
		  verset.insert(APT::VersionSet::FromPackage(CacheFile, V.ParentPkg(), APT::CacheSetHelper::CANDIDATE, helper));
		}
	    }

	    if (ShowOnlyFirstOr == true)
	       while ((D->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or) ++D;
	 }
   }

   for (APT::PackageSet::const_iterator Pkg = helper.virtualPkgs.begin();
	Pkg != helper.virtualPkgs.end(); ++Pkg)
      cout << '<' << Pkg.FullName(true) << '>' << endl;

   return true;
}
									/*}}}*/
// Depends - Print out a dependency tree				/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool Depends(CommandLine &CmdL)
{
   return ShowDepends(CmdL, false);
}
									/*}}}*/
// RDepends - Print out a reverse dependency tree			/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool RDepends(CommandLine &CmdL)
{
   return ShowDepends(CmdL, true);
}
									/*}}}*/
// xvcg - Generate a graph for xvcg					/*{{{*/
// ---------------------------------------------------------------------
// Code contributed from Junichi Uekawa <dancer@debian.org> on 20 June 2002.

static bool XVcg(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   bool GivenOnly = _config->FindB("APT::Cache::GivenOnly",false);
   
   /* Normal packages are boxes
      Pure Provides are triangles
      Mixed are diamonds
      rhomb are missing packages*/
   const char *Shapes[] = {"ellipse","triangle","box","rhomb"};
   
   /* Initialize the list of packages to show.
      1 = To Show
      2 = To Show no recurse
      3 = Emitted no recurse
      4 = Emitted
      0 = None */
   enum States {None=0, ToShow, ToShowNR, DoneNR, Done};
   enum TheFlags {ForceNR=(1<<0)};
   unsigned char *Show = new unsigned char[Cache->Head().PackageCount];
   unsigned char *Flags = new unsigned char[Cache->Head().PackageCount];
   unsigned char *ShapeMap = new unsigned char[Cache->Head().PackageCount];
   
   // Show everything if no arguments given
   if (CmdL.FileList[1] == 0)
      for (unsigned long I = 0; I != Cache->Head().PackageCount; I++)
	 Show[I] = ToShow;
   else
      for (unsigned long I = 0; I != Cache->Head().PackageCount; I++)
	 Show[I] = None;
   memset(Flags,0,sizeof(*Flags)*Cache->Head().PackageCount);
   
   // Map the shapes
   for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
   {   
      if (Pkg->VersionList == 0)
      {
	 // Missing
	 if (Pkg->ProvidesList == 0)
	    ShapeMap[Pkg->ID] = 0;
	 else
	    ShapeMap[Pkg->ID] = 1;
      }
      else
      {
	 // Normal
	 if (Pkg->ProvidesList == 0)
	    ShapeMap[Pkg->ID] = 2;
	 else
	    ShapeMap[Pkg->ID] = 3;
      }
   }

   // Load the list of packages from the command line into the show list
   APT::CacheSetHelper helper(true, GlobalError::NOTICE);
   std::list<APT::CacheSetHelper::PkgModifier> mods;
   mods.push_back(APT::CacheSetHelper::PkgModifier(0, ",", APT::PackageSet::Modifier::POSTFIX));
   mods.push_back(APT::CacheSetHelper::PkgModifier(1, "^", APT::PackageSet::Modifier::POSTFIX));
   std::map<unsigned short, APT::PackageSet> pkgsets =
		APT::PackageSet::GroupedFromCommandLine(CacheFile, CmdL.FileList + 1, mods, 0, helper);

   for (APT::PackageSet::const_iterator Pkg = pkgsets[0].begin();
	Pkg != pkgsets[0].end(); ++Pkg)
      Show[Pkg->ID] = ToShow;
   for (APT::PackageSet::const_iterator Pkg = pkgsets[1].begin();
	Pkg != pkgsets[1].end(); ++Pkg)
   {
      Show[Pkg->ID] = ToShow;
      Flags[Pkg->ID] |= ForceNR;
   }

   // Little header
   cout << "graph: { title: \"packages\"" << endl <<
     "xmax: 700 ymax: 700 x: 30 y: 30" << endl <<
     "layout_downfactor: 8" << endl;

   bool Act = true;
   while (Act == true)
   {
      Act = false;
      for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
      {
	 // See we need to show this package
	 if (Show[Pkg->ID] == None || Show[Pkg->ID] >= DoneNR)
	    continue;

	 //printf ("node: { title: \"%s\" label: \"%s\" }\n", Pkg.Name(), Pkg.Name());
	 
	 // Colour as done
	 if (Show[Pkg->ID] == ToShowNR || (Flags[Pkg->ID] & ForceNR) == ForceNR)
	 {
	    // Pure Provides and missing packages have no deps!
	    if (ShapeMap[Pkg->ID] == 0 || ShapeMap[Pkg->ID] == 1)
	       Show[Pkg->ID] = Done;
	    else
	       Show[Pkg->ID] = DoneNR;
	 }	 
	 else
	    Show[Pkg->ID] = Done;
	 Act = true;

	 // No deps to map out
	 if (Pkg->VersionList == 0 || Show[Pkg->ID] == DoneNR)
	    continue;
	 
	 pkgCache::VerIterator Ver = Pkg.VersionList();
	 for (pkgCache::DepIterator D = Ver.DependsList(); D.end() == false; ++D)
	 {
	    // See if anything can meet this dep
	    // Walk along the actual package providing versions
	    bool Hit = false;
	    pkgCache::PkgIterator DPkg = D.TargetPkg();
	    for (pkgCache::VerIterator I = DPkg.VersionList();
		      I.end() == false && Hit == false; ++I)
	    {
	       if (Cache->VS->CheckDep(I.VerStr(),D->CompareOp,D.TargetVer()) == true)
		  Hit = true;
	    }
	    
	    // Follow all provides
	    for (pkgCache::PrvIterator I = DPkg.ProvidesList(); 
		      I.end() == false && Hit == false; ++I)
	    {
	       if (Cache->VS->CheckDep(I.ProvideVersion(),D->CompareOp,D.TargetVer()) == false)
		  Hit = true;
	    }
	    

	    // Only graph critical deps	    
	    if (D.IsCritical() == true)
	    {
	       printf ("edge: { sourcename: \"%s\" targetname: \"%s\" class: 2 ",Pkg.FullName(true).c_str(), D.TargetPkg().FullName(true).c_str() );
	       
	       // Colour the node for recursion
	       if (Show[D.TargetPkg()->ID] <= DoneNR)
	       {
		  /* If a conflicts does not meet anything in the database
		     then show the relation but do not recurse */
		  if (Hit == false && D.IsNegative() == true)
		  {
		     if (Show[D.TargetPkg()->ID] == None && 
			 Show[D.TargetPkg()->ID] != ToShow)
			Show[D.TargetPkg()->ID] = ToShowNR;
		  }		  
		  else
		  {
		     if (GivenOnly == true && Show[D.TargetPkg()->ID] != ToShow)
			Show[D.TargetPkg()->ID] = ToShowNR;
		     else
			Show[D.TargetPkg()->ID] = ToShow;
		  }
	       }
	       
	       // Edge colour
	       switch(D->Type)
	       {
		  case pkgCache::Dep::Conflicts:
		    printf("label: \"conflicts\" color: lightgreen }\n");
		    break;
		  case pkgCache::Dep::DpkgBreaks:
		    printf("label: \"breaks\" color: lightgreen }\n");
		    break;
		  case pkgCache::Dep::Obsoletes:
		    printf("label: \"obsoletes\" color: lightgreen }\n");
		    break;
		  
		  case pkgCache::Dep::PreDepends:
		    printf("label: \"predepends\" color: blue }\n");
		    break;
		  
		  default:
		    printf("}\n");
		  break;
	       }	       
	    }	    
	 }
      }
   }   
   
   /* Draw the box colours after the fact since we can not tell what colour
      they should be until everything is finished drawing */
   for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
   {
      if (Show[Pkg->ID] < DoneNR)
	 continue;

      if (Show[Pkg->ID] == DoneNR)
	 printf("node: { title: \"%s\" label: \"%s\" color: orange shape: %s }\n", Pkg.FullName(true).c_str(), Pkg.FullName(true).c_str(),
		Shapes[ShapeMap[Pkg->ID]]);
      else
	printf("node: { title: \"%s\" label: \"%s\" shape: %s }\n", Pkg.FullName(true).c_str(), Pkg.FullName(true).c_str(),
		Shapes[ShapeMap[Pkg->ID]]);
      
   }

   delete[] Show;
   delete[] Flags;
   delete[] ShapeMap;

   printf("}\n");
   return true;
}
									/*}}}*/
// Dotty - Generate a graph for Dotty					/*{{{*/
// ---------------------------------------------------------------------
/* Dotty is the graphvis program for generating graphs. It is a fairly
   simple queuing algorithm that just writes dependencies and nodes. 
   http://www.research.att.com/sw/tools/graphviz/ */
static bool Dotty(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   bool GivenOnly = _config->FindB("APT::Cache::GivenOnly",false);
   
   /* Normal packages are boxes
      Pure Provides are triangles
      Mixed are diamonds
      Hexagons are missing packages*/
   const char *Shapes[] = {"hexagon","triangle","box","diamond"};
   
   /* Initialize the list of packages to show.
      1 = To Show
      2 = To Show no recurse
      3 = Emitted no recurse
      4 = Emitted
      0 = None */
   enum States {None=0, ToShow, ToShowNR, DoneNR, Done};
   enum TheFlags {ForceNR=(1<<0)};
   unsigned char *Show = new unsigned char[Cache->Head().PackageCount];
   unsigned char *Flags = new unsigned char[Cache->Head().PackageCount];
   unsigned char *ShapeMap = new unsigned char[Cache->Head().PackageCount];
   
   // Show everything if no arguments given
   if (CmdL.FileList[1] == 0)
      for (unsigned long I = 0; I != Cache->Head().PackageCount; I++)
	 Show[I] = ToShow;
   else
      for (unsigned long I = 0; I != Cache->Head().PackageCount; I++)
	 Show[I] = None;
   memset(Flags,0,sizeof(*Flags)*Cache->Head().PackageCount);
   
   // Map the shapes
   for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
   {   
      if (Pkg->VersionList == 0)
      {
	 // Missing
	 if (Pkg->ProvidesList == 0)
	    ShapeMap[Pkg->ID] = 0;
	 else
	    ShapeMap[Pkg->ID] = 1;
      }
      else
      {
	 // Normal
	 if (Pkg->ProvidesList == 0)
	    ShapeMap[Pkg->ID] = 2;
	 else
	    ShapeMap[Pkg->ID] = 3;
      }
   }

   // Load the list of packages from the command line into the show list
   APT::CacheSetHelper helper(true, GlobalError::NOTICE);
   std::list<APT::CacheSetHelper::PkgModifier> mods;
   mods.push_back(APT::CacheSetHelper::PkgModifier(0, ",", APT::PackageSet::Modifier::POSTFIX));
   mods.push_back(APT::CacheSetHelper::PkgModifier(1, "^", APT::PackageSet::Modifier::POSTFIX));
   std::map<unsigned short, APT::PackageSet> pkgsets =
		APT::PackageSet::GroupedFromCommandLine(CacheFile, CmdL.FileList + 1, mods, 0, helper);

   for (APT::PackageSet::const_iterator Pkg = pkgsets[0].begin();
	Pkg != pkgsets[0].end(); ++Pkg)
      Show[Pkg->ID] = ToShow;
   for (APT::PackageSet::const_iterator Pkg = pkgsets[1].begin();
	Pkg != pkgsets[1].end(); ++Pkg)
   {
      Show[Pkg->ID] = ToShow;
      Flags[Pkg->ID] |= ForceNR;
   }

   // Little header
   printf("digraph packages {\n");
   printf("concentrate=true;\n");
   printf("size=\"30,40\";\n");
   
   bool Act = true;
   while (Act == true)
   {
      Act = false;
      for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
      {
	 // See we need to show this package
	 if (Show[Pkg->ID] == None || Show[Pkg->ID] >= DoneNR)
	    continue;
	 
	 // Colour as done
	 if (Show[Pkg->ID] == ToShowNR || (Flags[Pkg->ID] & ForceNR) == ForceNR)
	 {
	    // Pure Provides and missing packages have no deps!
	    if (ShapeMap[Pkg->ID] == 0 || ShapeMap[Pkg->ID] == 1)
	       Show[Pkg->ID] = Done;
	    else
	       Show[Pkg->ID] = DoneNR;
	 }	 
	 else
	    Show[Pkg->ID] = Done;
	 Act = true;

	 // No deps to map out
	 if (Pkg->VersionList == 0 || Show[Pkg->ID] == DoneNR)
	    continue;
	 
	 pkgCache::VerIterator Ver = Pkg.VersionList();
	 for (pkgCache::DepIterator D = Ver.DependsList(); D.end() == false; ++D)
	 {
	    // See if anything can meet this dep
	    // Walk along the actual package providing versions
	    bool Hit = false;
	    pkgCache::PkgIterator DPkg = D.TargetPkg();
	    for (pkgCache::VerIterator I = DPkg.VersionList();
		      I.end() == false && Hit == false; ++I)
	    {
	       if (Cache->VS->CheckDep(I.VerStr(),D->CompareOp,D.TargetVer()) == true)
		  Hit = true;
	    }
	    
	    // Follow all provides
	    for (pkgCache::PrvIterator I = DPkg.ProvidesList(); 
		      I.end() == false && Hit == false; ++I)
	    {
	       if (Cache->VS->CheckDep(I.ProvideVersion(),D->CompareOp,D.TargetVer()) == false)
		  Hit = true;
	    }
	    
	    // Only graph critical deps	    
	    if (D.IsCritical() == true)
	    {
	       printf("\"%s\" -> \"%s\"",Pkg.FullName(true).c_str(),D.TargetPkg().FullName(true).c_str());
	       
	       // Colour the node for recursion
	       if (Show[D.TargetPkg()->ID] <= DoneNR)
	       {
		  /* If a conflicts does not meet anything in the database
		     then show the relation but do not recurse */
		  if (Hit == false && D.IsNegative() == true)
		  {
		     if (Show[D.TargetPkg()->ID] == None && 
			 Show[D.TargetPkg()->ID] != ToShow)
			Show[D.TargetPkg()->ID] = ToShowNR;
		  }		  
		  else
		  {
		     if (GivenOnly == true && Show[D.TargetPkg()->ID] != ToShow)
			Show[D.TargetPkg()->ID] = ToShowNR;
		     else
			Show[D.TargetPkg()->ID] = ToShow;
		  }
	       }
	       
	       // Edge colour
	       switch(D->Type)
	       {
		  case pkgCache::Dep::Conflicts:
		  case pkgCache::Dep::Obsoletes:
		  case pkgCache::Dep::DpkgBreaks:
		  printf("[color=springgreen];\n");
		  break;
		  
		  case pkgCache::Dep::PreDepends:
		  printf("[color=blue];\n");
		  break;
		  
		  default:
		  printf(";\n");
		  break;
	       }	       
	    }	    
	 }
      }
   }   
   
   /* Draw the box colours after the fact since we can not tell what colour
      they should be until everything is finished drawing */
   for (pkgCache::PkgIterator Pkg = Cache->PkgBegin(); Pkg.end() == false; ++Pkg)
   {
      if (Show[Pkg->ID] < DoneNR)
	 continue;
      
      // Orange box for early recursion stoppage
      if (Show[Pkg->ID] == DoneNR)
	 printf("\"%s\" [color=orange,shape=%s];\n",Pkg.FullName(true).c_str(),
		Shapes[ShapeMap[Pkg->ID]]);
      else
	 printf("\"%s\" [shape=%s];\n",Pkg.FullName(true).c_str(),
		Shapes[ShapeMap[Pkg->ID]]);
   }
   
   printf("}\n");
   delete[] Show;
   delete[] Flags;
   delete[] ShapeMap;
   return true;
}
									/*}}}*/
// DisplayRecord - Displays the complete record for the package		/*{{{*/
// ---------------------------------------------------------------------
/* This displays the package record from the proper package index file. 
   It is not used by DumpAvail for performance reasons. */

static APT_PURE unsigned char const* skipDescriptionFields(unsigned char const * DescP)
{
   char const * const TagName = "\nDescription";
   size_t const TagLen = strlen(TagName);
   while ((DescP = (unsigned char*)strchr((char*)DescP, '\n')) != NULL)
   {
      if (DescP[1] == ' ')
	 DescP += 2;
      else if (strncmp((char*)DescP, TagName, TagLen) == 0)
	 DescP += TagLen;
      else
	 break;
   }
   if (DescP != NULL)
      ++DescP;
   return DescP;
}
static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V)
{
   pkgCache *Cache = CacheFile.GetPkgCache();
   if (unlikely(Cache == NULL))
      return false;

   // Find an appropriate file
   pkgCache::VerFileIterator Vf = V.FileList();
   for (; Vf.end() == false; ++Vf)
      if ((Vf.File()->Flags & pkgCache::Flag::NotSource) == 0)
	 break;
   if (Vf.end() == true)
      Vf = V.FileList();
      
   // Check and load the package list file
   pkgCache::PkgFileIterator I = Vf.File();
   if (I.IsOk() == false)
      return _error->Error(_("Package file %s is out of sync."),I.FileName());

   FileFd PkgF;
   if (PkgF.Open(I.FileName(), FileFd::ReadOnly, FileFd::Extension) == false)
      return false;

   // Read the record (and ensure that it ends with a newline and NUL)
   unsigned char *Buffer = new unsigned char[Cache->HeaderP->MaxVerFileSize+2];
   Buffer[Vf->Size] = '\n';
   Buffer[Vf->Size+1] = '\0';
   if (PkgF.Seek(Vf->Offset) == false ||
       PkgF.Read(Buffer,Vf->Size) == false)
   {
      delete [] Buffer;
      return false;
   }

   // Get a pointer to start of Description field
   const unsigned char *DescP = (unsigned char*)strstr((char*)Buffer, "\nDescription");
   if (DescP != NULL)
      ++DescP;
   else
      DescP = Buffer + Vf->Size;

   // Write all but Description
   size_t const length = DescP - Buffer;
   if (length != 0 && FileFd::Write(STDOUT_FILENO, Buffer, length) == false)
   {
      delete [] Buffer;
      return false;
   }

   // Show the right description
   pkgRecords Recs(*Cache);
   pkgCache::DescIterator Desc = V.TranslatedDescription();
   if (Desc.end() == false)
   {
      pkgRecords::Parser &P = Recs.Lookup(Desc.FileList());
      cout << "Description" << ( (strcmp(Desc.LanguageCode(),"") != 0) ? "-" : "" ) << Desc.LanguageCode() << ": " << P.LongDesc();
      cout << std::endl << "Description-md5: " << Desc.md5() << std::endl;

      // Find the first field after the description (if there is any)
      DescP = skipDescriptionFields(DescP);
   }
   // else we have no translation, so we found a lonely Description-md5 -> don't skip it

   // write the rest of the buffer, but skip mixed in Descriptions* fields
   while (DescP != NULL)
   {
      const unsigned char * const Start = DescP;
      const unsigned char *End = (unsigned char*)strstr((char*)DescP, "\nDescription");
      if (End == NULL)
      {
	 End = &Buffer[Vf->Size];
	 DescP = NULL;
      }
      else
      {
	 ++End; // get the newline into the output
	 DescP = skipDescriptionFields(End + strlen("Description"));
      }
      size_t const length = End - Start;
      if (length != 0 && FileFd::Write(STDOUT_FILENO, Start, length) == false)
      {
	 delete [] Buffer;
	 return false;
      }
   }

   // write a final newline after the last field
   cout<<endl;

   delete [] Buffer;
   return true;
}
									/*}}}*/
struct ExDescFile
{
   pkgCache::DescFile *Df;
   map_id_t ID;
};

// Search - Perform a search						/*{{{*/
// ---------------------------------------------------------------------
/* This searches the package names and package descriptions for a pattern */
static bool Search(CommandLine &CmdL)
{
   bool const ShowFull = _config->FindB("APT::Cache::ShowFull",false);
   bool const NamesOnly = _config->FindB("APT::Cache::NamesOnly",false);
   unsigned int const NumPatterns = CmdL.FileSize() -1;
   
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   pkgDepCache::Policy *Plcy = CacheFile.GetPolicy();
   if (unlikely(Cache == NULL || Plcy == NULL))
      return false;

   // Make sure there is at least one argument
   if (NumPatterns < 1)
      return _error->Error(_("You must give at least one search pattern"));
   
   // Compile the regex pattern
   regex_t *Patterns = new regex_t[NumPatterns];
   memset(Patterns,0,sizeof(*Patterns)*NumPatterns);
   for (unsigned I = 0; I != NumPatterns; I++)
   {
      if (regcomp(&Patterns[I],CmdL.FileList[I+1],REG_EXTENDED | REG_ICASE | 
		  REG_NOSUB) != 0)
      {
	 for (; I != 0; I--)
	    regfree(&Patterns[I]);
	 return _error->Error("Regex compilation error");
      }      
   }
   
   if (_error->PendingError() == true)
   {
      for (unsigned I = 0; I != NumPatterns; I++)
	 regfree(&Patterns[I]);
      return false;
   }
   
   size_t const descCount = Cache->HeaderP->GroupCount + 1;
   ExDescFile *DFList = new ExDescFile[descCount];
   memset(DFList,0,sizeof(*DFList) * descCount);

   bool *PatternMatch = new bool[descCount * NumPatterns];
   memset(PatternMatch,false,sizeof(*PatternMatch) * descCount * NumPatterns);

   // Map versions that we want to write out onto the VerList array.
   for (pkgCache::GrpIterator G = Cache->GrpBegin(); G.end() == false; ++G)
   {
      size_t const PatternOffset = G->ID * NumPatterns;
      size_t unmatched = 0, matched = 0;
      for (unsigned I = 0; I < NumPatterns; ++I)
      {
	 if (PatternMatch[PatternOffset + I] == true)
	    ++matched;
	 else if (regexec(&Patterns[I],G.Name(),0,0,0) == 0)
	    PatternMatch[PatternOffset + I] = true;
	 else
	    ++unmatched;
      }

      // already dealt with this package?
      if (matched == NumPatterns)
	 continue;

      // Doing names only, drop any that don't match..
      if (NamesOnly == true && unmatched == NumPatterns)
	 continue;

      // Find the proper version to use
      pkgCache::PkgIterator P = G.FindPreferredPkg();
      if (P.end() == true)
	 continue;
      pkgCache::VerIterator V = Plcy->GetCandidateVer(P);
      if (V.end() == false)
      {
	 pkgCache::DescIterator const D = V.TranslatedDescription();
	 //FIXME: packages without a description can't be found
	 if (D.end() == true)
	    continue;
	 DFList[G->ID].Df = D.FileList();
	 DFList[G->ID].ID = G->ID;
      }

      if (unmatched == NumPatterns)
	 continue;

      // Include all the packages that provide matching names too
      for (pkgCache::PrvIterator Prv = P.ProvidesList() ; Prv.end() == false; ++Prv)
      {
	 pkgCache::VerIterator V = Plcy->GetCandidateVer(Prv.OwnerPkg());
	 if (V.end() == true)
	    continue;

	 unsigned long id = Prv.OwnerPkg().Group()->ID;
	 pkgCache::DescIterator const D = V.TranslatedDescription();
	 //FIXME: packages without a description can't be found
	 if (D.end() == true)
	    continue;
	 DFList[id].Df = D.FileList();
	 DFList[id].ID = id;

	 size_t const PrvPatternOffset = id * NumPatterns;
	 for (unsigned I = 0; I < NumPatterns; ++I)
	    PatternMatch[PrvPatternOffset + I] = PatternMatch[PatternOffset + I];
      }
   }

   LocalitySort(&DFList->Df,Cache->HeaderP->GroupCount,sizeof(*DFList));

   // Create the text record parser
   pkgRecords Recs(*Cache);
   // Iterate over all the version records and check them
   for (ExDescFile *J = DFList; J->Df != 0; ++J)
   {
      pkgRecords::Parser &P = Recs.Lookup(pkgCache::DescFileIterator(*Cache,J->Df));
      size_t const PatternOffset = J->ID * NumPatterns;

      if (NamesOnly == false)
      {
	 string const LongDesc = P.LongDesc();
	 for (unsigned I = 0; I < NumPatterns; ++I)
	 {
	    if (PatternMatch[PatternOffset + I] == true)
	       continue;
	    else if (regexec(&Patterns[I],LongDesc.c_str(),0,0,0) == 0)
	       PatternMatch[PatternOffset + I] = true;
	 }
      }

      bool matchedAll = true;
      for (unsigned I = 0; I < NumPatterns; ++I)
	 if (PatternMatch[PatternOffset + I] == false)
	 {
	    matchedAll = false;
	    break;
	 }

      if (matchedAll == true)
      {
	 if (ShowFull == true)
	 {
	    const char *Start;
	    const char *End;
	    P.GetRec(Start,End);
	    fwrite(Start,End-Start,1,stdout);
	    putc('\n',stdout);
	 }	 
	 else
	    printf("%s - %s\n",P.Name().c_str(),P.ShortDesc().c_str());
      }
   }
   
   delete [] DFList;
   delete [] PatternMatch;
   for (unsigned I = 0; I != NumPatterns; I++)
      regfree(&Patterns[I]);
   if (ferror(stdout))
       return _error->Error("Write to stdout failed");
   return true;
}
									/*}}}*/
/* ShowAuto - show automatically installed packages (sorted)		{{{*/
static bool ShowAuto(CommandLine &)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   pkgDepCache *DepCache = CacheFile.GetDepCache();
   if (unlikely(Cache == NULL || DepCache == NULL))
      return false;

   std::vector<string> packages;
   packages.reserve(Cache->HeaderP->PackageCount / 3);
   
   for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
      if ((*DepCache)[P].Flags & pkgCache::Flag::Auto)
         packages.push_back(P.Name());

    std::sort(packages.begin(), packages.end());
    
    for (vector<string>::iterator I = packages.begin(); I != packages.end(); ++I)
            cout << *I << "\n";

   _error->Notice(_("This command is deprecated. Please use 'apt-mark showauto' instead."));
   return true;
}
									/*}}}*/
// ShowPackage - Dump the package record to the screen			/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool ShowPackage(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   CacheSetHelperVirtuals helper(true, GlobalError::NOTICE);
   APT::CacheSetHelper::VerSelector const select = _config->FindB("APT::Cache::AllVersions", true) ?
			APT::CacheSetHelper::ALL : APT::CacheSetHelper::CANDIDATE;
   APT::VersionList const verset = APT::VersionList::FromCommandLine(CacheFile, CmdL.FileList + 1, select, helper);
   for (APT::VersionList::const_iterator Ver = verset.begin(); Ver != verset.end(); ++Ver)
      if (DisplayRecord(CacheFile, Ver) == false)
	 return false;

   if (verset.empty() == true)
   {
      if (helper.virtualPkgs.empty() == true)
        return _error->Error(_("No packages found"));
      else
        _error->Notice(_("No packages found"));
   }
   return true;
}
									/*}}}*/
// ShowPkgNames - Show package names					/*{{{*/
// ---------------------------------------------------------------------
/* This does a prefix match on the first argument */
static bool ShowPkgNames(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   if (unlikely(CacheFile.BuildCaches(NULL, false) == false))
      return false;
   pkgCache::GrpIterator I = CacheFile.GetPkgCache()->GrpBegin();
   bool const All = _config->FindB("APT::Cache::AllNames","false");

   if (CmdL.FileList[1] != 0)
   {
      for (;I.end() != true; ++I)
      {
	 if (All == false && I->FirstPackage == 0)
	    continue;
	 if (I.FindPkg("any")->VersionList == 0)
	    continue;
	 if (strncmp(I.Name(),CmdL.FileList[1],strlen(CmdL.FileList[1])) == 0)
	    cout << I.Name() << endl;
      }

      return true;
   }
   
   // Show all pkgs
   for (;I.end() != true; ++I)
   {
      if (All == false && I->FirstPackage == 0)
	 continue;
      if (I.FindPkg("any")->VersionList == 0)
	 continue;
      cout << I.Name() << endl;
   }
   
   return true;
}
									/*}}}*/
// ShowSrcPackage - Show source package records				/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool ShowSrcPackage(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   pkgSourceList *List = CacheFile.GetSourceList();
   if (unlikely(List == NULL))
      return false;

   // Create the text record parsers
   pkgSrcRecords SrcRecs(*List);
   if (_error->PendingError() == true)
      return false;

   unsigned found = 0;
   for (const char **I = CmdL.FileList + 1; *I != 0; I++)
   {
      SrcRecs.Restart();
      
      pkgSrcRecords::Parser *Parse;
      unsigned found_this = 0;
      while ((Parse = SrcRecs.Find(*I,false)) != 0) {
        cout << Parse->AsStr() << endl;;
        found++;
        found_this++;
      }
      if (found_this == 0) {
        _error->Warning(_("Unable to locate package %s"),*I);
        continue;
      }
   }
   if (found == 0)
      _error->Notice(_("No packages found"));
   return true;
}
									/*}}}*/
// Policy - Show the results of the preferences file			/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool Policy(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   pkgCache *Cache = CacheFile.GetPkgCache();
   pkgPolicy *Plcy = CacheFile.GetPolicy();
   pkgSourceList *SrcList = CacheFile.GetSourceList();
   if (unlikely(Cache == NULL || Plcy == NULL || SrcList == NULL))
      return false;

   /* Should the MultiArchKiller be run to see which pseudo packages for an
      arch all package are currently installed? Activating it gives a speed
      penality for no real gain beside enhanced debugging, so in general no. */
   if (_config->FindB("APT::Cache::Policy::DepCache", false) == true)
      CacheFile.GetDepCache();

   // Print out all of the package files
   if (CmdL.FileList[1] == 0)
   {
      cout << _("Package files:") << endl;   
      for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F.end() == false; ++F)
      {
	 // Locate the associated index files so we can derive a description
	 pkgIndexFile *Indx;
	 if (SrcList->FindIndex(F,Indx) == false &&
	     _system->FindIndex(F,Indx) == false)
	    return _error->Error(_("Cache is out of sync, can't x-ref a package file"));
	 
	 printf("%4i %s\n",
		Plcy->GetPriority(F),Indx->Describe(true).c_str());
	 
	 // Print the reference information for the package
	 string Str = F.RelStr();
	 if (Str.empty() == false)
	    printf("     release %s\n",F.RelStr().c_str());
	 if (F.Site() != 0 && F.Site()[0] != 0)
	    printf("     origin %s\n",F.Site());
      }
      
      // Show any packages have explicit pins
      cout << _("Pinned packages:") << endl;
      pkgCache::PkgIterator I = Cache->PkgBegin();
      for (;I.end() != true; ++I)
      {
	 if (Plcy->GetPriority(I) == 0)
	    continue;

	 // Print the package name and the version we are forcing to
	 cout << "     " << I.FullName(true) << " -> ";
	 
	 pkgCache::VerIterator V = Plcy->GetMatch(I);
	 if (V.end() == true)
	    cout << _("(not found)") << endl;
	 else
	    cout << V.VerStr() << endl;
      }     
      
      return true;
   }

   char const * const msgInstalled = _("  Installed: ");
   char const * const msgCandidate = _("  Candidate: ");
   short const InstalledLessCandidate =
		mbstowcs(NULL, msgInstalled, 0) - mbstowcs(NULL, msgCandidate, 0);
   short const deepInstalled =
		(InstalledLessCandidate < 0 ? (InstalledLessCandidate*-1) : 0) - 1;
   short const deepCandidate =
		(InstalledLessCandidate > 0 ? (InstalledLessCandidate) : 0) - 1;

   // Print out detailed information for each package
   APT::CacheSetHelper helper(true, GlobalError::NOTICE);
   APT::PackageList pkgset = APT::PackageList::FromCommandLine(CacheFile, CmdL.FileList + 1, helper);
   for (APT::PackageList::const_iterator Pkg = pkgset.begin(); Pkg != pkgset.end(); ++Pkg)
   {
      cout << Pkg.FullName(true) << ":" << endl;

      // Installed version
      cout << msgInstalled << OutputInDepth(deepInstalled, " ");
      if (Pkg->CurrentVer == 0)
	 cout << _("(none)") << endl;
      else
	 cout << Pkg.CurrentVer().VerStr() << endl;
      
      // Candidate Version 
      cout << msgCandidate << OutputInDepth(deepCandidate, " ");
      pkgCache::VerIterator V = Plcy->GetCandidateVer(Pkg);
      if (V.end() == true)
	 cout << _("(none)") << endl;
      else
	 cout << V.VerStr() << endl;

      // Pinned version
      if (Plcy->GetPriority(Pkg) != 0)
      {
	 cout << _("  Package pin: ");
	 V = Plcy->GetMatch(Pkg);
	 if (V.end() == true)
	    cout << _("(not found)") << endl;
	 else
	    cout << V.VerStr() << endl;
      }
      
      // Show the priority tables
      cout << _("  Version table:") << endl;
      for (V = Pkg.VersionList(); V.end() == false; ++V)
      {
	 if (Pkg.CurrentVer() == V)
	    cout << " *** " << V.VerStr();
	 else
	    cout << "     " << V.VerStr();
	 cout << " " << Plcy->GetPriority(Pkg) << endl;
	 for (pkgCache::VerFileIterator VF = V.FileList(); VF.end() == false; ++VF)
	 {
	    // Locate the associated index files so we can derive a description
	    pkgIndexFile *Indx;
	    if (SrcList->FindIndex(VF.File(),Indx) == false &&
		_system->FindIndex(VF.File(),Indx) == false)
	       return _error->Error(_("Cache is out of sync, can't x-ref a package file"));
	    printf("       %4i %s\n",Plcy->GetPriority(VF.File()),
		   Indx->Describe(true).c_str());
	 }
      }
   }
   
   return true;
}
									/*}}}*/
// Madison - Look a bit like katie's madison				/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool Madison(CommandLine &CmdL)
{
   pkgCacheFile CacheFile;
   pkgSourceList *SrcList = CacheFile.GetSourceList();

   if (SrcList == 0)
      return false;

   // Create the src text record parsers and ignore errors about missing
   // deb-src lines that are generated from pkgSrcRecords::pkgSrcRecords
   pkgSrcRecords SrcRecs(*SrcList);
   if (_error->PendingError() == true)
      _error->Discard();

   APT::CacheSetHelper helper(true, GlobalError::NOTICE);
   for (const char **I = CmdL.FileList + 1; *I != 0; I++)
   {
      _error->PushToStack();
      APT::PackageList pkgset = APT::PackageList::FromString(CacheFile, *I, helper);
      for (APT::PackageList::const_iterator Pkg = pkgset.begin(); Pkg != pkgset.end(); ++Pkg)
      {
         for (pkgCache::VerIterator V = Pkg.VersionList(); V.end() == false; ++V)
         {
            for (pkgCache::VerFileIterator VF = V.FileList(); VF.end() == false; ++VF)
            {
// This might be nice, but wouldn't uniquely identify the source -mdz
//                if (VF.File().Archive() != 0)
//                {
//                   cout << setw(10) << Pkg.Name() << " | " << setw(10) << V.VerStr() << " | "
//                        << VF.File().Archive() << endl;
//                }

               // Locate the associated index files so we can derive a description
               for (pkgSourceList::const_iterator S = SrcList->begin(); S != SrcList->end(); ++S)
               {
                    vector<pkgIndexFile *> *Indexes = (*S)->GetIndexFiles();
                    for (vector<pkgIndexFile *>::const_iterator IF = Indexes->begin();
                         IF != Indexes->end(); ++IF)
                    {
                         if ((*IF)->FindInCache(*(VF.File().Cache())) == VF.File())
                         {
                                   cout << setw(10) << Pkg.FullName(true) << " | " << setw(10) << V.VerStr() << " | "
                                        << (*IF)->Describe(true) << endl;
                         }
                    }
               }
            }
         }
      }

      SrcRecs.Restart();
      pkgSrcRecords::Parser *SrcParser;
      bool foundSomething = false;
      while ((SrcParser = SrcRecs.Find(*I, false)) != 0)
      {
         foundSomething = true;
         // Maybe support Release info here too eventually
         cout << setw(10) << SrcParser->Package() << " | "
              << setw(10) << SrcParser->Version() << " | "
              << SrcParser->Index().Describe(true) << endl;
      }
      if (foundSomething == true)
	 _error->RevertToStack();
      else
	 _error->MergeWithStack();
   }

   return true;
}
									/*}}}*/
// GenCaches - Call the main cache generator				/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool GenCaches(CommandLine &)
{
   OpTextProgress Progress(*_config);

   pkgCacheFile CacheFile;
   return CacheFile.BuildCaches(&Progress, true);
}
									/*}}}*/
// ShowHelp - Show a help screen					/*{{{*/
// ---------------------------------------------------------------------
/* */
static bool ShowHelp(CommandLine &)
{
   ioprintf(cout,_("%s %s for %s compiled on %s %s\n"),PACKAGE,PACKAGE_VERSION,
	    COMMON_ARCH,__DATE__,__TIME__);
   
   if (_config->FindB("version") == true)
     return true;

   cout << 
    _("Usage: apt-cache [options] command\n"
      "       apt-cache [options] showpkg pkg1 [pkg2 ...]\n"
      "       apt-cache [options] showsrc pkg1 [pkg2 ...]\n"
      "\n"
      "apt-cache is a low-level tool used to query information\n"
      "from APT's binary cache files\n"
      "\n"
      "Commands:\n"
      "   gencaches - Build both the package and source cache\n"
      "   showpkg - Show some general information for a single package\n"
      "   showsrc - Show source records\n"
      "   stats - Show some basic statistics\n"
      "   dump - Show the entire file in a terse form\n"
      "   dumpavail - Print an available file to stdout\n"
      "   unmet - Show unmet dependencies\n"
      "   search - Search the package list for a regex pattern\n"
      "   show - Show a readable record for the package\n"
      "   depends - Show raw dependency information for a package\n"
      "   rdepends - Show reverse dependency information for a package\n"
      "   pkgnames - List the names of all packages in the system\n"
      "   dotty - Generate package graphs for GraphViz\n"
      "   xvcg - Generate package graphs for xvcg\n"
      "   policy - Show policy settings\n"
      "\n"
      "Options:\n"
      "  -h   This help text.\n"
      "  -p=? The package cache.\n"
      "  -s=? The source cache.\n"
      "  -q   Disable progress indicator.\n"
      "  -i   Show only important deps for the unmet command.\n"
      "  -c=? Read this configuration file\n"
      "  -o=? Set an arbitrary configuration option, eg -o dir::cache=/tmp\n"
      "See the apt-cache(8) and apt.conf(5) manual pages for more information.\n");
   return true;
}
									/*}}}*/
int main(int argc,const char *argv[])					/*{{{*/
{
   CommandLine::Dispatch Cmds[] =  {{"help",&ShowHelp},
                                    {"gencaches",&GenCaches},
                                    {"showsrc",&ShowSrcPackage},
                                    {"showpkg",&DumpPackage},
                                    {"stats",&Stats},
                                    {"dump",&Dump},
                                    {"dumpavail",&DumpAvail},
                                    {"unmet",&UnMet},
                                    {"search",&Search},
                                    {"depends",&Depends},
                                    {"rdepends",&RDepends},
                                    {"dotty",&Dotty},
                                    {"xvcg",&XVcg},
                                    {"show",&ShowPackage},
                                    {"pkgnames",&ShowPkgNames},
                                    {"showauto",&ShowAuto},
                                    {"policy",&Policy},
                                    {"madison",&Madison},
                                    {0,0}};

   std::vector<CommandLine::Args> Args = getCommandArgs("apt-cache", CommandLine::GetCommand(Cmds, argc, argv));

   // Set up gettext support
   setlocale(LC_ALL,"");
   textdomain(PACKAGE);

   // Parse the command line and initialize the package library
   CommandLine CmdL(Args.data(),_config);
   if (pkgInitConfig(*_config) == false ||
       CmdL.Parse(argc,argv) == false ||
       pkgInitSystem(*_config,_system) == false)
   {
      _error->DumpErrors();
      return 100;
   }

   // See if the help should be shown
   if (_config->FindB("help") == true ||
       CmdL.FileSize() == 0)
   {
      ShowHelp(CmdL);
      return 0;
   }
   
   // Deal with stdout not being a tty
   if (!isatty(STDOUT_FILENO) && _config->FindI("quiet", -1) == -1)
      _config->Set("quiet","1");

   if (_config->Exists("APT::Cache::Generate") == true)
      _config->Set("pkgCacheFile::Generate", _config->FindB("APT::Cache::Generate", true));

   // Match the operation
   CmdL.DispatchArg(Cmds);

   // Print any errors or warnings found during parsing
   bool const Errors = _error->PendingError();
   if (_config->FindI("quiet",0) > 0)
      _error->DumpErrors();
   else
      _error->DumpErrors(GlobalError::DEBUG);
   return Errors == true ? 100 : 0;
}
									/*}}}*/