- Use the tarfile module to unpack tarfiles.
- Allow setting the destination install directory. If this is set then
  it is used for the modules, other items (header files, etc) are not
  installed, and warnings are printed if the package would have liked to.

Unfortunaltey binary installs seem broken due to a tarfile bug (#721871)
or my misunderstanding of how tarfile works.
diff --git a/Lib/plat-mac/pimp.py b/Lib/plat-mac/pimp.py
index 786f40a..8998990 100644
--- a/Lib/plat-mac/pimp.py
+++ b/Lib/plat-mac/pimp.py
@@ -22,6 +22,9 @@
 import distutils.util
 import distutils.sysconfig
 import md5
+import tarfile
+import tempfile
+import shutil
 
 __all__ = ["PimpPreferences", "PimpDatabase", "PimpPackage", "main"]
 
@@ -42,13 +45,101 @@
 DEFAULT_INSTALLDIR=distutils.sysconfig.get_python_lib()
 DEFAULT_PIMPDATABASE="http://www.cwi.nl/~jack/pimp/pimp-%s.plist" % distutils.util.get_platform()
 
+def _cmd(output, dir, *cmditems):
+    """Internal routine to run a shell command in a given directory."""
+    
+    cmd = ("cd \"%s\"; " % dir) + " ".join(cmditems)
+    if output:
+        output.write("+ %s\n" % cmd)
+    if NO_EXECUTE:
+        return 0
+    child = popen2.Popen4(cmd)
+    child.tochild.close()
+    while 1:
+        line = child.fromchild.readline()
+        if not line:
+            break
+        if output:
+            output.write(line)
+    return child.wait()
+
+class PimpUnpacker:
+    """Abstract base class - Unpacker for archives"""
+    
+    _can_rename = False
+    
+    def __init__(self, argument,
+            dir="",
+            renames=[]):
+        self.argument = argument
+        if renames and not self._can_rename:
+            raise RuntimeError, "This unpacker cannot rename files"
+        self._dir = dir
+        self._renames = renames
+                
+    def unpack(self, archive, output=None):
+        return None
+        
+class PimpCommandUnpacker(PimpUnpacker):
+    """Unpack archives by calling a Unix utility"""
+    
+    _can_rename = False
+    
+    def unpack(self, archive, output=None):
+        cmd = self.argument % archive
+        if _cmd(output, self._dir, cmd):
+            return "unpack command failed"
+            
+class PimpTarUnpacker(PimpUnpacker):
+    """Unpack tarfiles using the builtin tarfile module"""
+    
+    _can_rename = True
+    
+    def unpack(self, archive, output=None):
+        tf = tarfile.open(archive, "r")
+        members = tf.getmembers()
+        skip = []
+        if self._renames:
+            for member in members:
+                for oldprefix, newprefix in self._renames:
+                    if oldprefix[:len(self._dir)] == self._dir:
+                        oldprefix2 = oldprefix[len(self._dir):]
+                    else:
+                        oldprefix2 = None
+                    if member.name[:len(oldprefix)] == oldprefix:
+                        if newprefix is None:
+                            skip.append(member)
+                            #print 'SKIP', member.name
+                        else:
+                            member.name = newprefix + member.name[len(oldprefix):]
+                            print '    ', member.name
+                        break
+                    elif oldprefix2 and member.name[:len(oldprefix2)] == oldprefix2:
+                        if newprefix is None:
+                            skip.append(member)
+                            #print 'SKIP', member.name
+                        else:
+                            member.name = newprefix + member.name[len(oldprefix2):]
+                            #print '    ', member.name
+                        break
+                else:
+                    skip.append(member)
+                    #print '????', member.name
+        for member in members:
+            if member in skip:
+                continue
+            tf.extract(member, self._dir)
+        if skip:
+            names = [member.name for member in skip if member.name[-1] != '/']
+            return "Not all files were unpacked: %s" % " ".join(names)
+        
 ARCHIVE_FORMATS = [
-    (".tar.Z", "zcat \"%s\" | tar -xf -"),
-    (".taz", "zcat \"%s\" | tar -xf -"),
-    (".tar.gz", "zcat \"%s\" | tar -xf -"),
-    (".tgz", "zcat \"%s\" | tar -xf -"),
-    (".tar.bz", "bzcat \"%s\" | tar -xf -"),
-    (".zip", "unzip \"%s\""),
+    (".tar.Z", PimpTarUnpacker, None),
+    (".taz", PimpTarUnpacker, None),
+    (".tar.gz", PimpTarUnpacker, None),
+    (".tgz", PimpTarUnpacker, None),
+    (".tar.bz", PimpTarUnpacker, None),
+    (".zip", PimpCommandUnpacker, "unzip \"%s\""),
 ]
 
 class PimpPreferences:
@@ -67,10 +158,18 @@
             downloadDir = DEFAULT_DOWNLOADDIR
         if not buildDir:
             buildDir = DEFAULT_BUILDDIR
-        if not installDir:
-            installDir = DEFAULT_INSTALLDIR
         if not pimpDatabase:
             pimpDatabase = DEFAULT_PIMPDATABASE
+        if installDir:
+            # Installing to non-standard location.
+            self.installLocations = [
+                ('--install-lib', installDir),
+                ('--install-headers', None),
+                ('--install-scripts', None),
+                ('--install-data', None)]
+        else:
+            installDir = DEFAULT_INSTALLDIR
+            self.installLocations = []
         self.flavorOrder = flavorOrder
         self.downloadDir = downloadDir
         self.buildDir = buildDir
@@ -106,7 +205,7 @@
                     break
             else:
                 rv += "Warning: Install directory \"%s\" is not on sys.path\n" % self.installDir
-        return rv           
+        return rv
         
     def compareFlavors(self, left, right):
         """Compare two flavor strings. This is part of your preferences
@@ -388,23 +487,6 @@
             rv.append((pkg, descr))
         return rv
             
-    def _cmd(self, output, dir, *cmditems):
-        """Internal routine to run a shell command in a given directory."""
-        
-        cmd = ("cd \"%s\"; " % dir) + " ".join(cmditems)
-        if output:
-            output.write("+ %s\n" % cmd)
-        if NO_EXECUTE:
-            return 0
-        child = popen2.Popen4(cmd)
-        child.tochild.close()
-        while 1:
-            line = child.fromchild.readline()
-            if not line:
-                break
-            if output:
-                output.write(line)
-        return child.wait()
         
     def downloadPackageOnly(self, output=None):
         """Download a single package, if needed.
@@ -425,7 +507,7 @@
         if not self._archiveOK():
             if scheme == 'manual':
                 return "Please download package manually and save as %s" % self.archiveFilename
-            if self._cmd(output, self._db.preferences.downloadDir,
+            if _cmd(output, self._db.preferences.downloadDir,
                     "curl",
                     "--output", self.archiveFilename,
                     self._dict['Download-URL']):
@@ -451,15 +533,16 @@
         """Unpack a downloaded package archive."""
         
         filename = os.path.split(self.archiveFilename)[1]
-        for ext, cmd in ARCHIVE_FORMATS:
+        for ext, unpackerClass, arg in ARCHIVE_FORMATS:
             if filename[-len(ext):] == ext:
                 break
         else:
             return "unknown extension for archive file: %s" % filename
         self.basename = filename[:-len(ext)]
-        cmd = cmd % self.archiveFilename
-        if self._cmd(output, self._db.preferences.buildDir, cmd):
-            return "unpack command failed"
+        unpacker = unpackerClass(arg, dir=self._db.preferences.buildDir)
+        rv = unpacker.unpack(self.archiveFilename, output=output)
+        if rv:
+            return rv
             
     def installPackageOnly(self, output=None):
         """Default install method, to be overridden by subclasses"""
@@ -527,37 +610,48 @@
         
         If output is given it should be a file-like object and it
         will receive a log of what happened."""
-        print 'PimpPackage_binary installPackageOnly'
                     
-        msgs = []
-        if self._dict.has_key('Pre-install-command'):
-            msg.append("%s: Pre-install-command ignored" % self.fullname())
         if self._dict.has_key('Install-command'):
-            msgs.append("%s: Install-command ignored" % self.fullname())
-        if self._dict.has_key('Post-install-command'):
-            msgs.append("%s: Post-install-command ignored" % self.fullname())
+            return "%s: Binary package cannot have Install-command" % self.fullname()
+                    
+        if self._dict.has_key('Pre-install-command'):
+            if _cmd(output, self._buildDirname, self._dict['Pre-install-command']):
+                return "pre-install %s: running \"%s\" failed" % \
+                    (self.fullname(), self._dict['Pre-install-command'])
                     
         self.beforeInstall()
 
         # Install by unpacking
         filename = os.path.split(self.archiveFilename)[1]
-        for ext, cmd in ARCHIVE_FORMATS:
+        for ext, unpackerClass, arg in ARCHIVE_FORMATS:
             if filename[-len(ext):] == ext:
                 break
         else:
-            return "unknown extension for archive file: %s" % filename
+            return "%s: unknown extension for archive file: %s" % (self.fullname(), filename)
+        self.basename = filename[:-len(ext)]
         
-        # Extract the files in the root folder.
-        cmd = cmd % self.archiveFilename
-        if self._cmd(output, "/", cmd):
-            return "unpack command failed"
+        install_renames = []
+        for k, newloc in self._db.preferences.installLocations:
+            if not newloc:
+                continue
+            if k == "--install-lib":
+                oldloc = DEFAULT_INSTALLDIR
+            else:
+                return "%s: Don't know installLocation %s" % (self.fullname(), k)
+            install_renames.append((oldloc, newloc))
+                
+        unpacker = unpackerClass(arg, dir="/", renames=install_renames)
+        rv = unpacker.unpack(self.archiveFilename, output=output)
+        if rv:
+            return rv
         
         self.afterInstall()
         
         if self._dict.has_key('Post-install-command'):
-            if self._cmd(output, self._buildDirname, self._dict['Post-install-command']):
-                return "post-install %s: running \"%s\" failed" % \
+            if _cmd(output, self._buildDirname, self._dict['Post-install-command']):
+                return "%s: post-install: running \"%s\" failed" % \
                     (self.fullname(), self._dict['Post-install-command'])
+
         return None
         
     
@@ -579,22 +673,44 @@
         will receive a log of what happened."""
                     
         if self._dict.has_key('Pre-install-command'):
-            if self._cmd(output, self._buildDirname, self._dict['Pre-install-command']):
+            if _cmd(output, self._buildDirname, self._dict['Pre-install-command']):
                 return "pre-install %s: running \"%s\" failed" % \
                     (self.fullname(), self._dict['Pre-install-command'])
                     
         self.beforeInstall()
         installcmd = self._dict.get('Install-command')
+        if installcmd and self._install_renames:
+            return "Package has install-command and can only be installed to standard location"
+        # This is the "bit-bucket" for installations: everything we don't
+        # want. After installation we check that it is actually empty
+        unwanted_install_dir = None
         if not installcmd:
-            installcmd = '"%s" setup.py install' % sys.executable
-        if self._cmd(output, self._buildDirname, installcmd):
+            extra_args = ""
+            for k, v in self._db.preferences.installLocations:
+                if not v:
+                    # We don't want these files installed. Send them
+                    # to the bit-bucket.
+                    if not unwanted_install_dir:
+                        unwanted_install_dir = tempfile.mkdtemp()
+                    v = unwanted_install_dir
+                extra_args = extra_args + " %s \"%s\"" % (k, v)
+            installcmd = '"%s" setup.py install %s' % (sys.executable, extra_args)
+        if _cmd(output, self._buildDirname, installcmd):
             return "install %s: running \"%s\" failed" % \
                 (self.fullname(), installcmd)
+        if unwanted_install_dir and os.path.exists(unwanted_install_dir):
+            unwanted_files = os.listdir(unwanted_install_dir)
+            if unwanted_files:
+                rv = "Warning: some files were not installed: %s" % " ".join(unwanted_files)
+            else:
+                rv = None
+            shutil.rmtree(unwanted_install_dir)
+            return rv
         
         self.afterInstall()
         
         if self._dict.has_key('Post-install-command'):
-            if self._cmd(output, self._buildDirname, self._dict['Post-install-command']):
+            if _cmd(output, self._buildDirname, self._dict['Post-install-command']):
                 return "post-install %s: running \"%s\" failed" % \
                     (self.fullname(), self._dict['Post-install-command'])
         return None
@@ -672,11 +788,13 @@
         
         
     
-def _run(mode, verbose, force, args):
+def _run(mode, verbose, force, args, prefargs):
     """Engine for the main program"""
     
-    prefs = PimpPreferences()
-    prefs.check()
+    prefs = PimpPreferences(**prefargs)
+    rv = prefs.check()
+    if rv:
+        sys.stdout.write(rv)
     db = PimpDatabase(prefs)
     db.appendURL(prefs.pimpDatabase)
     
@@ -697,7 +815,10 @@
             print "%-20.20s\t%s" % (pkgname, description)
             if verbose:
                 print "\tHome page:\t", pkg.homepage()
-                print "\tDownload URL:\t", pkg.downloadURL()
+                try:
+                    print "\tDownload URL:\t", pkg.downloadURL()
+                except KeyError:
+                    pass
     elif mode =='status':
         if not args:
             args = db.listnames()
@@ -751,17 +872,18 @@
     
     import getopt
     def _help():
-        print "Usage: pimp [-v] -s [package ...]  List installed status"
-        print "       pimp [-v] -l [package ...]  Show package information"
-        print "       pimp [-vf] -i package ...   Install packages"
-        print "       pimp -d                     Dump database to stdout"
+        print "Usage: pimp [options] -s [package ...]  List installed status"
+        print "       pimp [options] -l [package ...]  Show package information"
+        print "       pimp [options] -i package ...    Install packages"
+        print "       pimp -d                          Dump database to stdout"
         print "Options:"
-        print "       -v  Verbose"
-        print "       -f  Force installation"
+        print "       -v     Verbose"
+        print "       -f     Force installation"
+        print "       -D dir Set destination directory (default: site-packages)"
         sys.exit(1)
         
     try:
-        opts, args = getopt.getopt(sys.argv[1:], "slifvd")
+        opts, args = getopt.getopt(sys.argv[1:], "slifvdD:")
     except getopt.Error:
         _help()
     if not opts and not args:
@@ -769,6 +891,7 @@
     mode = None
     force = 0
     verbose = 0
+    prefargs = {}
     for o, a in opts:
         if o == '-s':
             if mode:
@@ -788,9 +911,11 @@
             force = 1
         if o == '-v':
             verbose = 1
+        if o == '-D':
+            prefargs['installDir'] = a
     if not mode:
         _help()
-    _run(mode, verbose, force, args)
+    _run(mode, verbose, force, args, prefargs)
                 
 if __name__ == '__main__':
     main()