[ABI-Break] remove the PACKAGE_MATCHER_ABI_COMPAT defines
[apt.git] / apt-pkg / aptconfiguration.cc
index 0fe84db74c63690d8f52d48edfd60a10629fc96a..e32e553a424ad34cb65f50a58148269e25f7c957 100644 (file)
@@ -8,14 +8,23 @@
    ##################################################################### */
                                                                        /*}}}*/
 // Include Files                                                       /*{{{*/
-#include <apt-pkg/fileutl.h>
+#include <config.h>
+
 #include <apt-pkg/aptconfiguration.h>
 #include <apt-pkg/configuration.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/fileutl.h>
 #include <apt-pkg/macros.h>
+#include <apt-pkg/strutl.h>
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <fcntl.h>
 
-#include <vector>
-#include <string>
 #include <algorithm>
+#include <string>
+#include <vector>
                                                                        /*}}}*/
 namespace APT {
 // getCompressionTypes - Return Vector of usbale compressiontypes      /*{{{*/
@@ -33,12 +42,12 @@ const Configuration::getCompressionTypes(bool const &Cached) {
 
        // setup the defaults for the compressiontypes => method mapping
        _config->CndSet("Acquire::CompressionTypes::bz2","bzip2");
+       _config->CndSet("Acquire::CompressionTypes::xz","xz");
        _config->CndSet("Acquire::CompressionTypes::lzma","lzma");
        _config->CndSet("Acquire::CompressionTypes::gz","gzip");
 
-       // Set default application paths to check for optional compression types
-       _config->CndSet("Dir::Bin::lzma", "/usr/bin/lzma");
-       _config->CndSet("Dir::Bin::bzip2", "/bin/bzip2");
+       setDefaultConfigurationForCompressors();
+       std::vector<APT::Configuration::Compressor> const compressors = getCompressors();
 
        // accept non-list order as override setting for config settings on commandline
        std::string const overrideOrder = _config->Find("Acquire::CompressionTypes::Order","");
@@ -48,19 +57,21 @@ const Configuration::getCompressionTypes(bool const &Cached) {
        // load the order setting into our vector
        std::vector<std::string> const order = _config->FindVector("Acquire::CompressionTypes::Order");
        for (std::vector<std::string>::const_iterator o = order.begin();
-            o != order.end(); o++) {
+            o != order.end(); ++o) {
                if ((*o).empty() == true)
                        continue;
                // ignore types we have no method ready to use
-               if (_config->Exists(string("Acquire::CompressionTypes::").append(*o)) == false)
+               std::string const method = std::string("Acquire::CompressionTypes::").append(*o);
+               if (_config->Exists(method) == false)
                        continue;
                // ignore types we have no app ready to use
-               string const appsetting = string("Dir::Bin::").append(*o);
-               if (_config->Exists(appsetting) == true) {
-                       std::string const app = _config->FindFile(appsetting.c_str(), "");
-                       if (app.empty() == false && FileExists(app) == false)
-                               continue;
-               }
+               std::string const app = _config->Find(method);
+               std::vector<APT::Configuration::Compressor>::const_iterator c = compressors.begin();
+               for (; c != compressors.end(); ++c)
+                       if (c->Name == app)
+                               break;
+               if (c == compressors.end())
+                       continue;
                types.push_back(*o);
        }
 
@@ -76,15 +87,23 @@ const Configuration::getCompressionTypes(bool const &Cached) {
                if (std::find(types.begin(),types.end(),Types->Tag) != types.end())
                        continue;
                // ignore types we have no app ready to use
-               string const appsetting = string("Dir::Bin::").append(Types->Value);
-               if (appsetting.empty() == false && _config->Exists(appsetting) == true) {
-                       std::string const app = _config->FindFile(appsetting.c_str(), "");
-                       if (app.empty() == false && FileExists(app) == false)
-                               continue;
-               }
+               std::vector<APT::Configuration::Compressor>::const_iterator c = compressors.begin();
+               for (; c != compressors.end(); ++c)
+                       if (c->Name == Types->Value)
+                               break;
+               if (c == compressors.end())
+                       continue;
                types.push_back(Types->Tag);
        }
 
+       // add the special "uncompressed" type
+       if (std::find(types.begin(), types.end(), "uncompressed") == types.end())
+       {
+               std::string const uncompr = _config->FindFile("Dir::Bin::uncompressed", "");
+               if (uncompr.empty() == true || FileExists(uncompr) == true)
+                       types.push_back("uncompressed");
+       }
+
        return types;
 }
                                                                        /*}}}*/
@@ -97,7 +116,7 @@ const Configuration::getCompressionTypes(bool const &Cached) {
    will result in "de_DE, de, en".
    The special word "none" is the stopcode for the not-All code vector */
 std::vector<std::string> const Configuration::getLanguages(bool const &All,
-                               bool const &Cached, char const * const Locale) {
+                               bool const &Cached, char const ** const Locale) {
        using std::string;
 
        // The detection is boring and has a lot of cornercases,
@@ -118,112 +137,199 @@ std::vector<std::string> const Configuration::getLanguages(bool const &All,
                }
        }
 
-       // get the environment language code
-       // we extract both, a long and a short code and then we will
-       // check if we actually need both (rare) or if the short is enough
-       string const envMsg = string(Locale == 0 ? std::setlocale(LC_MESSAGES, NULL) : Locale);
-       size_t const lenShort = (envMsg.find('_') != string::npos) ? envMsg.find('_') : 2;
-       size_t const lenLong = (envMsg.find('.') != string::npos) ? envMsg.find('.') : (lenShort + 3);
-
-       string envLong = envMsg.substr(0,lenLong);
-       string const envShort = envLong.substr(0,lenShort);
-       bool envLongIncluded = true, envShortIncluded = false;
-
-       // first cornercase: LANG=C, so we use only "en" Translation
-       if (envLong == "C") {
-               codes.push_back("en");
-               return codes;
-       }
-
-       if (envLong != envShort) {
-               // to save the servers from unneeded queries, we only try also long codes
-               // for languages it is realistic to have a long code translation file...
-               char const *needLong[] = { "cs", "en", "pt", "sv", "zh", NULL };
-               for (char const **l = needLong; *l != NULL; l++)
-                       if (envShort.compare(*l) == 0) {
-                               envLongIncluded = false;
-                               break;
+       // Include all Language codes we have a Translation file for in /var/lib/apt/lists
+       // so they will be all included in the Cache.
+       std::vector<string> builtin;
+       DIR *D = opendir(_config->FindDir("Dir::State::lists").c_str());
+       if (D != 0) {
+               builtin.push_back("none");
+               for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) {
+                       string const name = SubstVar(Ent->d_name, "%5f", "_");
+                       size_t const foundDash = name.rfind("-");
+                       size_t const foundUnderscore = name.rfind("_", foundDash);
+                       if (foundDash == string::npos || foundUnderscore == string::npos ||
+                           foundDash <= foundUnderscore ||
+                           name.substr(foundUnderscore+1, foundDash-(foundUnderscore+1)) != "Translation")
+                               continue;
+                       string const c = name.substr(foundDash+1);
+                       if (unlikely(c.empty() == true) || c == "en")
+                               continue;
+                       // Skip unusual files, like backups or that alike
+                       string::const_iterator s = c.begin();
+                       for (;s != c.end(); ++s) {
+                               if (isalpha(*s) == 0 && *s != '_')
+                                       break;
                        }
+                       if (s != c.end())
+                               continue;
+                       if (std::find(builtin.begin(), builtin.end(), c) != builtin.end())
+                               continue;
+                       builtin.push_back(c);
+               }
        }
-
-       // we don't add the long code, but we allow the user to do so
-       if (envLongIncluded == true)
-               envLong.clear();
+       closedir(D);
 
        // FIXME: Remove support for the old APT::Acquire::Translation
        // it was undocumented and so it should be not very widthly used
        string const oldAcquire = _config->Find("APT::Acquire::Translation","");
        if (oldAcquire.empty() == false && oldAcquire != "environment") {
+               // TRANSLATORS: the two %s are APT configuration options
+               _error->Notice("Option '%s' is deprecated. Please use '%s' instead, see 'man 5 apt.conf' for details.",
+                               "APT::Acquire::Translation", "Acquire::Languages");
                if (oldAcquire != "none")
                        codes.push_back(oldAcquire);
-               return codes;
+               codes.push_back("en");
+               allCodes = codes;
+               for (std::vector<string>::const_iterator b = builtin.begin();
+                    b != builtin.end(); ++b)
+                       if (std::find(allCodes.begin(), allCodes.end(), *b) == allCodes.end())
+                               allCodes.push_back(*b);
+               if (All == true)
+                       return allCodes;
+               else
+                       return codes;
+       }
+
+       // get the environment language codes: LC_MESSAGES (and later LANGUAGE)
+       // we extract both, a long and a short code and then we will
+       // check if we actually need both (rare) or if the short is enough
+       string const envMsg = string(Locale == 0 ? std::setlocale(LC_MESSAGES, NULL) : *Locale);
+       size_t const lenShort = (envMsg.find('_') != string::npos) ? envMsg.find('_') : 2;
+       size_t const lenLong = (envMsg.find_first_of(".@") != string::npos) ? envMsg.find_first_of(".@") : (lenShort + 3);
+
+       string const envLong = envMsg.substr(0,lenLong);
+       string const envShort = envLong.substr(0,lenShort);
+
+       // It is very likely we will need the environment codes later,
+       // so let us generate them now from LC_MESSAGES and LANGUAGE
+       std::vector<string> environment;
+       if (envShort != "C") {
+               // take care of LC_MESSAGES
+               if (envLong != envShort)
+                       environment.push_back(envLong);
+               environment.push_back(envShort);
+               // take care of LANGUAGE
+               const char *language_env = getenv("LANGUAGE") == 0 ? "" : getenv("LANGUAGE");
+               string envLang = Locale == 0 ? language_env : *(Locale+1);
+               if (envLang.empty() == false) {
+                       std::vector<string> env = VectorizeString(envLang,':');
+                       short addedLangs = 0; // add a maximum of 3 fallbacks from the environment
+                       for (std::vector<string>::const_iterator e = env.begin();
+                            e != env.end() && addedLangs < 3; ++e) {
+                               if (unlikely(e->empty() == true) || *e == "en")
+                                       continue;
+                               if (*e == envLong || *e == envShort)
+                                       continue;
+                               if (std::find(environment.begin(), environment.end(), *e) != environment.end())
+                                       continue;
+                               ++addedLangs;
+                               environment.push_back(*e);
+                       }
+               }
+       } else {
+               environment.push_back("en");
        }
 
-       // Support settings like Acquire::Translation=none on the command line to
+       // Support settings like Acquire::Languages=none on the command line to
        // override the configuration settings vector of languages.
        string const forceLang = _config->Find("Acquire::Languages","");
        if (forceLang.empty() == false) {
-               if (forceLang == "environment") {
-                       if (envLongIncluded == false)
-                               codes.push_back(envLong);
-                       if (envShortIncluded == false)
-                               codes.push_back(envShort);
+               if (forceLang == "none") {
+                       codes.clear();
+                       allCodes.clear();
+                       allCodes.push_back("none");
+               } else {
+                       if (forceLang == "environment")
+                               codes = environment;
+                       else
+                               codes.push_back(forceLang);
+                       allCodes = codes;
+                       for (std::vector<string>::const_iterator b = builtin.begin();
+                            b != builtin.end(); ++b)
+                               if (std::find(allCodes.begin(), allCodes.end(), *b) == allCodes.end())
+                                       allCodes.push_back(*b);
+               }
+               if (All == true)
+                       return allCodes;
+               else
+                       return codes;
+       }
+
+       // cornercase: LANG=C, so we use only "en" Translation
+       if (envShort == "C") {
+               allCodes = codes = environment;
+               allCodes.insert(allCodes.end(), builtin.begin(), builtin.end());
+               if (All == true)
+                       return allCodes;
+               else
                        return codes;
-               } else if (forceLang != "none")
-                       codes.push_back(forceLang);
-               return codes;
        }
 
        std::vector<string> const lang = _config->FindVector("Acquire::Languages");
        // the default setting -> "environment, en"
        if (lang.empty() == true) {
-               if (envLongIncluded == false)
-                       codes.push_back(envLong);
-               if (envShortIncluded == false)
-                       codes.push_back(envShort);
+               codes = environment;
                if (envShort != "en")
                        codes.push_back("en");
-               return codes;
+               allCodes = codes;
+               for (std::vector<string>::const_iterator b = builtin.begin();
+                    b != builtin.end(); ++b)
+                       if (std::find(allCodes.begin(), allCodes.end(), *b) == allCodes.end())
+                               allCodes.push_back(*b);
+               if (All == true)
+                       return allCodes;
+               else
+                       return codes;
        }
 
        // the configs define the order, so add the environment
        // then needed and ensure the codes are not listed twice.
        bool noneSeen = false;
        for (std::vector<string>::const_iterator l = lang.begin();
-            l != lang.end(); l++) {
+            l != lang.end(); ++l) {
                if (*l == "environment") {
-                       if (envLongIncluded == true && envShortIncluded == true)
-                               continue;
-                       if (envLongIncluded == false) {
-                               envLongIncluded = true;
-                               if (noneSeen == false)
-                                       codes.push_back(envLong);
-                               allCodes.push_back(envLong);
-                       }
-                       if (envShortIncluded == false) {
-                               envShortIncluded = true;
+                       for (std::vector<string>::const_iterator e = environment.begin();
+                            e != environment.end(); ++e) {
+                               if (std::find(allCodes.begin(), allCodes.end(), *e) != allCodes.end())
+                                       continue;
                                if (noneSeen == false)
-                                       codes.push_back(envShort);
-                               allCodes.push_back(envShort);
+                                       codes.push_back(*e);
+                               allCodes.push_back(*e);
                        }
                        continue;
                } else if (*l == "none") {
                        noneSeen = true;
                        continue;
-               } else if ((envLongIncluded == true && *l == envLong) ||
-                        (envShortIncluded == true && *l == envShort))
+               } else if (std::find(allCodes.begin(), allCodes.end(), *l) != allCodes.end())
                        continue;
 
                if (noneSeen == false)
                        codes.push_back(*l);
                allCodes.push_back(*l);
        }
+
+       for (std::vector<string>::const_iterator b = builtin.begin();
+            b != builtin.end(); ++b)
+               if (std::find(allCodes.begin(), allCodes.end(), *b) == allCodes.end())
+                       allCodes.push_back(*b);
+
        if (All == true)
                return allCodes;
        else
                return codes;
 }
                                                                        /*}}}*/
+// checkLanguage - are we interested in the given Language?            /*{{{*/
+bool const Configuration::checkLanguage(std::string Lang, bool const All) {
+       // the empty Language is always interesting as it is the original
+       if (Lang.empty() == true)
+               return true;
+       // filenames are encoded, so undo this
+       Lang = SubstVar(Lang, "%5f", "_");
+       std::vector<std::string> const langs = getLanguages(All, true);
+       return (std::find(langs.begin(), langs.end(), Lang) != langs.end());
+}
+                                                                       /*}}}*/
 // getArchitectures - Return Vector of prefered Architectures          /*{{{*/
 std::vector<std::string> const Configuration::getArchitectures(bool const &Cached) {
        using std::string;
@@ -234,9 +340,102 @@ std::vector<std::string> const Configuration::getArchitectures(bool const &Cache
 
        string const arch = _config->Find("APT::Architecture");
        archs = _config->FindVector("APT::Architectures");
+
+       if (unlikely(arch.empty() == true))
+               return archs;
+
+       // FIXME: It is a bit unclean to have debian specific code here…
+       if (archs.empty() == true) {
+               archs.push_back(arch);
+
+               // Generate the base argument list for dpkg
+               std::vector<const char *> Args;
+               string Tmp = _config->Find("Dir::Bin::dpkg","dpkg");
+               {
+                       string const dpkgChrootDir = _config->FindDir("DPkg::Chroot-Directory", "/");
+                       size_t dpkgChrootLen = dpkgChrootDir.length();
+                       if (dpkgChrootDir != "/" && Tmp.find(dpkgChrootDir) == 0) {
+                               if (dpkgChrootDir[dpkgChrootLen - 1] == '/')
+                                       --dpkgChrootLen;
+                               Tmp = Tmp.substr(dpkgChrootLen);
+                       }
+               }
+               Args.push_back(Tmp.c_str());
+
+               // Stick in any custom dpkg options
+               ::Configuration::Item const *Opts = _config->Tree("DPkg::Options");
+               if (Opts != 0) {
+                       Opts = Opts->Child;
+                       for (; Opts != 0; Opts = Opts->Next)
+                       {
+                               if (Opts->Value.empty() == true)
+                                       continue;
+                               Args.push_back(Opts->Value.c_str());
+                       }
+               }
+
+               Args.push_back("--print-foreign-architectures");
+               Args.push_back(NULL);
+
+               int external[2] = {-1, -1};
+               if (pipe(external) != 0)
+               {
+                       _error->WarningE("getArchitecture", "Can't create IPC pipe for dpkg --print-foreign-architectures");
+                       return archs;
+               }
+
+               pid_t dpkgMultiArch = ExecFork();
+               if (dpkgMultiArch == 0) {
+                       close(external[0]);
+                       std::string const chrootDir = _config->FindDir("DPkg::Chroot-Directory");
+                       int const nullfd = open("/dev/null", O_RDONLY);
+                       dup2(nullfd, STDIN_FILENO);
+                       dup2(external[1], STDOUT_FILENO);
+                       dup2(nullfd, STDERR_FILENO);
+                       if (chrootDir != "/" && chroot(chrootDir.c_str()) != 0)
+                               _error->WarningE("getArchitecture", "Couldn't chroot into %s for dpkg --print-foreign-architectures", chrootDir.c_str());
+                       execvp(Args[0], (char**) &Args[0]);
+                       _error->WarningE("getArchitecture", "Can't detect foreign architectures supported by dpkg!");
+                       _exit(100);
+               }
+               close(external[1]);
+
+               FILE *dpkg = fdopen(external[0], "r");
+               if(dpkg != NULL) {
+                       char buf[1024];
+                       while (fgets(buf, sizeof(buf), dpkg) != NULL) {
+                               char* arch = strtok(buf, " ");
+                               while (arch != NULL) {
+                                       for (; isspace(*arch) != 0; ++arch);
+                                       if (arch[0] != '\0') {
+                                               char const* archend = arch;
+                                               for (; isspace(*archend) == 0 && *archend != '\0'; ++archend);
+                                               string a(arch, (archend - arch));
+                                               if (std::find(archs.begin(), archs.end(), a) == archs.end())
+                                                       archs.push_back(a);
+                                       }
+                                       arch = strtok(NULL, " ");
+                               }
+                       }
+                       fclose(dpkg);
+               }
+               ExecWait(dpkgMultiArch, "dpkg --print-foreign-architectures", true);
+               return archs;
+       }
+
        if (archs.empty() == true ||
            std::find(archs.begin(), archs.end(), arch) == archs.end())
-               archs.push_back(arch);
+               archs.insert(archs.begin(), arch);
+
+       // erase duplicates and empty strings
+       for (std::vector<string>::reverse_iterator a = archs.rbegin();
+            a != archs.rend(); ++a) {
+               if (a->empty() == true || std::find(a + 1, archs.rend(), *a) != archs.rend())
+                       archs.erase(a.base()-1);
+               if (a == archs.rend())
+                       break;
+       }
+
        return archs;
 }
                                                                        /*}}}*/
@@ -248,4 +447,115 @@ bool const Configuration::checkArchitecture(std::string const &Arch) {
        return (std::find(archs.begin(), archs.end(), Arch) != archs.end());
 }
                                                                        /*}}}*/
+// setDefaultConfigurationForCompressors                               /*{{{*/
+void Configuration::setDefaultConfigurationForCompressors() {
+       // Set default application paths to check for optional compression types
+       _config->CndSet("Dir::Bin::bzip2", "/bin/bzip2");
+       _config->CndSet("Dir::Bin::xz", "/usr/bin/xz");
+       if (FileExists(_config->FindFile("Dir::Bin::xz")) == true) {
+               _config->Clear("Dir::Bin::lzma");
+               _config->Set("APT::Compressor::lzma::Binary", "xz");
+               if (_config->Exists("APT::Compressor::lzma::CompressArg") == false) {
+                       _config->Set("APT::Compressor::lzma::CompressArg::", "--format=lzma");
+                       _config->Set("APT::Compressor::lzma::CompressArg::", "-9");
+               }
+               if (_config->Exists("APT::Compressor::lzma::UncompressArg") == false) {
+                       _config->Set("APT::Compressor::lzma::UncompressArg::", "--format=lzma");
+                       _config->Set("APT::Compressor::lzma::UncompressArg::", "-d");
+               }
+       } else {
+               _config->CndSet("Dir::Bin::lzma", "/usr/bin/lzma");
+               if (_config->Exists("APT::Compressor::lzma::CompressArg") == false) {
+                       _config->Set("APT::Compressor::lzma::CompressArg::", "--suffix=");
+                       _config->Set("APT::Compressor::lzma::CompressArg::", "-9");
+               }
+               if (_config->Exists("APT::Compressor::lzma::UncompressArg") == false) {
+                       _config->Set("APT::Compressor::lzma::UncompressArg::", "--suffix=");
+                       _config->Set("APT::Compressor::lzma::UncompressArg::", "-d");
+               }
+       }
+}
+                                                                       /*}}}*/
+// getCompressors - Return Vector of usbale compressors                        /*{{{*/
+// ---------------------------------------------------------------------
+/* return a vector of compressors used by apt-ftparchive in the
+   multicompress functionality or to detect data.tar files */
+std::vector<APT::Configuration::Compressor>
+const Configuration::getCompressors(bool const Cached) {
+       static std::vector<APT::Configuration::Compressor> compressors;
+       if (compressors.empty() == false) {
+               if (Cached == true)
+                       return compressors;
+               else
+                       compressors.clear();
+       }
+
+       setDefaultConfigurationForCompressors();
+
+       compressors.push_back(Compressor(".", "", "", NULL, NULL, 1));
+       if (_config->Exists("Dir::Bin::gzip") == false || FileExists(_config->FindFile("Dir::Bin::gzip")) == true)
+               compressors.push_back(Compressor("gzip",".gz","gzip","-9n","-d",2));
+#ifdef HAVE_ZLIB
+       else
+               compressors.push_back(Compressor("gzip",".gz","false", NULL, NULL, 2));
+#endif
+       if (_config->Exists("Dir::Bin::bzip2") == false || FileExists(_config->FindFile("Dir::Bin::bzip2")) == true)
+               compressors.push_back(Compressor("bzip2",".bz2","bzip2","-9","-d",3));
+#ifdef HAVE_BZ2
+       else
+               compressors.push_back(Compressor("bzip2",".bz2","false", NULL, NULL, 3));
+#endif
+       if (_config->Exists("Dir::Bin::xz") == false || FileExists(_config->FindFile("Dir::Bin::xz")) == true)
+               compressors.push_back(Compressor("xz",".xz","xz","-6","-d",4));
+       if (_config->Exists("Dir::Bin::lzma") == false || FileExists(_config->FindFile("Dir::Bin::lzma")) == true)
+               compressors.push_back(Compressor("lzma",".lzma","lzma","-9","-d",5));
+
+       std::vector<std::string> const comp = _config->FindVector("APT::Compressor");
+       for (std::vector<std::string>::const_iterator c = comp.begin();
+            c != comp.end(); ++c) {
+               if (*c == "." || *c == "gzip" || *c == "bzip2" || *c == "lzma" || *c == "xz")
+                       continue;
+               compressors.push_back(Compressor(c->c_str(), std::string(".").append(*c).c_str(), c->c_str(), "-9", "-d", 100));
+       }
+
+       return compressors;
+}
+                                                                       /*}}}*/
+// getCompressorExtensions - supported data.tar extensions             /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+std::vector<std::string> const Configuration::getCompressorExtensions() {
+       std::vector<APT::Configuration::Compressor> const compressors = getCompressors();
+       std::vector<std::string> ext;
+       for (std::vector<APT::Configuration::Compressor>::const_iterator c = compressors.begin();
+            c != compressors.end(); ++c)
+               if (c->Extension.empty() == false && c->Extension != ".")
+                       ext.push_back(c->Extension);
+       return ext;
+}
+                                                                       /*}}}*/
+// Compressor constructor                                              /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+Configuration::Compressor::Compressor(char const *name, char const *extension,
+                                     char const *binary,
+                                     char const *compressArg, char const *uncompressArg,
+                                     unsigned short const cost) {
+       std::string const config = std::string("APT::Compressor::").append(name).append("::");
+       Name = _config->Find(std::string(config).append("Name"), name);
+       Extension = _config->Find(std::string(config).append("Extension"), extension);
+       Binary = _config->Find(std::string(config).append("Binary"), binary);
+       Cost = _config->FindI(std::string(config).append("Cost"), cost);
+       std::string const compConf = std::string(config).append("CompressArg");
+       if (_config->Exists(compConf) == true)
+               CompressArgs = _config->FindVector(compConf);
+       else if (compressArg != NULL)
+               CompressArgs.push_back(compressArg);
+       std::string const uncompConf = std::string(config).append("UncompressArg");
+       if (_config->Exists(uncompConf) == true)
+               UncompressArgs = _config->FindVector(uncompConf);
+       else if (uncompressArg != NULL)
+               UncompressArgs.push_back(uncompressArg);
+}
+                                                                       /*}}}*/
 }