Gzip support

uc1541

@@ -43,13 +43,19 @@ script behaviour:
 
 UC1541_DEBUG - if set, uc1541 will produce log in /tmp/uc1541.log file
 
-UC1541_VERBOSE - of set, script will be more verbose, i.e. error messages form
+UC1541_VERBOSE - if set, script will be more verbose, i.e. error messages form
 c1541 program will be passed to Midnight Commander, so that user will be aware
 of error cause if any.
 
 UC1541_HIDE_DEL - if set, no DEL entries will be shown
 
 Changelog:
+    2.7 Added support for gzipped disk images
+    2.6 Added mkdir and run handling (or rather lack of handling :). Minor
+        refactoring.
+    2.5 Fixed bug with filenames started with a '-' sign.
+    2.4 Fixed endless loop bug for reading directory in Python implemented
+        directory reader.
     2.3 Re added and missing method _correct_fname used for writing files
         into d64 image.
     2.2 Fixed bug(?) with unusual sector end (marked as sector 0, not 255),
@@ -68,14 +74,15 @@ Changelog:
     1.0 Initial release
 
 Author: Roman 'gryf' Dobosz <gryf73@gmail.com>
-Date: 2012-09-24
-Version: 2.3
+Date: 2013-11-12
+Version: 2.7
 Licence: BSD
 """
 
 import sys
 import re
 import os
+import gzip
 from subprocess import Popen, PIPE
 
 if os.getenv('UC1541_DEBUG'):
@@ -91,7 +98,7 @@ if os.getenv('UC1541_DEBUG'):
 else:
     class LOG(object):
         """
-        Dummy logger object. does nothing.
+        Dummy logger object. Does nothing.
         """
         @classmethod
         def debug(*args, **kwargs):
@@ -148,14 +155,30 @@ class D64(object):
         Init
         """
         LOG.debug('image: %s', dimage)
-        dimage = open(dimage, 'rb')
-        self.raw = dimage.read()
-        dimage.close()
-
+        self.raw = None
         self.current_sector_data = None
         self.next_sector = 0
         self.next_track = None
         self._dir_contents = []
+        self._already_done = []
+
+        self._get_raw(dimage)
+
+    def _get_raw(self, dimage):
+        """Try to get contents of the D64 image either it's gzip compressed or
+        not."""
+        fobj = gzip.open(dimage)
+        # Although the common approach with gzipped files is to check the
+        # magic number, in this case there is no guarantee that first track
+        # does not contain exactly the same byte sequence as the magic number.
+        # So the only way left is to actually try to uncompress the file.
+        try:
+            self.raw = fobj.read()
+        except IOError:
+            fobj.close()
+            fobj = open(dimage)
+            self.raw = fobj.read()
+            fobj.close()
 
     def _map_filename(self, string):
         """
@@ -172,6 +195,10 @@ class D64(object):
             character = D64.CHAR_MAP.get(ord(chr_), '?')
             filename.append(character)
 
+        # special cases
+        if filename[0] == "-":
+            filename[0] = "?"
+
         LOG.debug("string: ``%s'' mapped to: ``%s''", string,
                   "".join(filename))
         return "".join(filename)
@@ -182,7 +209,11 @@ class D64(object):
         Return False if the chain ends, True otherwise
         """
 
-        if self.next_track == 0 and self.next_sector in (0, 255):
+        # Well, self.next_sector _should_ have value $FF, but apparently there
+        # are the cases where it is not, therefore checking for that will not
+        # be performed and value of $00 on the next track will end the
+        # directory
+        if self.next_track == 0:
             LOG.debug("End of directory")
             return False
 
@@ -198,6 +229,15 @@ class D64(object):
 
         self.next_track = ord(self.current_sector_data[0])
         self.next_sector = ord(self.current_sector_data[1])
+
+        if (self.next_track, self.next_sector) in self._already_done:
+            # Just a failsafe. Endless loop is not what is expected.
+            LOG.debug("Loop in track/sector pointer at %d,%d",
+                      self.next_track, self.next_sector)
+            self._already_done = []
+            return False
+
+        self._already_done.append((self.next_track, self.next_sector))
         LOG.debug("Next track: %s,%s", self.next_track, self.next_sector)
         return True
 
@@ -239,7 +279,7 @@ class D64(object):
         Traverse through sectors and store entries in _dir_contents
         """
         sector = self.current_sector_data
-        for x in range(8):
+        for dummy in range(8):
             entry = sector[:32]
             ftype = ord(entry[2])
 
@@ -352,6 +392,16 @@ class Uc1541(object):
 
         return 0
 
+    def mkdir(self, dirname):
+        """Not supported"""
+        self.err = "D64 format doesn't support directories"
+        return self._show_error()
+
+    def run(self, fname):
+        """Not supported"""
+        self.err = "Not supported, unless you are using MC on real C64 ;)"
+        return self._show_error()
+
     def _correct_fname(self, fname):
         """
         Return filename with mapped characters, without .prg extension.
@@ -418,9 +468,13 @@ class Uc1541(object):
                 if '/' in display_name:
                     display_name = display_name.replace('/', '|')
 
-                # workaround for space at the beggining of the filename
-                if display_name[0] == ' ':
-                    display_name = '~' + display_name[1:]
+                # workaround for space and dash at the beggining of the
+                # filename
+                char_map = {' ': '~',
+                            '-': '_'}
+                display_name = "".join([char_map.get(display_name[0],
+                                                     display_name[0]),
+                                        display_name[1:]])
 
                 if ext == 'del':
                     perms = "----------"
@@ -441,9 +495,9 @@ class Uc1541(object):
         Pass out error output from c1541 execution
         """
         if self._verbose:
-            sys.exit(self.err)
+            return self.err
         else:
-            sys.exit(1)
+            return 1
 
     def _call_command(self, cmd, src=None, dst=None):
         """
@@ -465,16 +519,16 @@ class Uc1541(object):
         return not self.err
 
 
-CALL_MAP = {'list': lambda a: Uc1541(a.ARCH).list(),
-            'copyin': lambda a: Uc1541(a.ARCH).copyin(a.SRC, a.DST),
-            'copyout': lambda a: Uc1541(a.ARCH).copyout(a.SRC, a.DST),
-            'rm': lambda a: Uc1541(a.ARCH).rm(a.DST)}
+CALL_MAP = {'list': lambda a: Uc1541(a.arch).list(),
+            'copyin': lambda a: Uc1541(a.arch).copyin(a.src, a.dst),
+            'copyout': lambda a: Uc1541(a.arch).copyout(a.src, a.dst),
+            'mkdir': lambda a: Uc1541(a.arch).mkdir(a.dst),
+            'rm': lambda a: Uc1541(a.arch).rm(a.dst),
+            'run': lambda a: Uc1541(a.arch).run(a.dst)}
 
 
 def parse_args():
-    """
-    Use ArgumentParser to check for script arguments and execute.
-    """
+    """Use ArgumentParser to check for script arguments and execute."""
     parser = ArgumentParser()
     subparsers = parser.add_subparsers(help='supported commands')
     parser_list = subparsers.add_parser('list', help="List contents of D64 "
@@ -484,67 +538,79 @@ def parse_args():
     parser_copyout = subparsers.add_parser('copyout', help="Copy file out of "
                                            "D64 image")
     parser_rm = subparsers.add_parser('rm', help="Delete file from D64 image")
+    parser_mkdir = subparsers.add_parser('mkdir', help="Create directory in "
+                                         "archive")
+    parser_run = subparsers.add_parser('run', help="Execute archived file")
 
-    parser_list.add_argument('ARCH', help="D64 Image filename")
+    parser_list.add_argument('arch', help="D64 Image filename")
     parser_list.set_defaults(func=CALL_MAP['list'])
 
-    parser_copyin.add_argument('ARCH', help="D64 Image filename")
-    parser_copyin.add_argument('SRC', help="Source filename")
-    parser_copyin.add_argument('DST', help="Destination filename (to be "
+    parser_copyin.add_argument('arch', help="D64 Image filename")
+    parser_copyin.add_argument('src', help="Source filename")
+    parser_copyin.add_argument('dst', help="Destination filename (to be "
                                "written into D64 image)")
     parser_copyin.set_defaults(func=CALL_MAP['copyin'])
 
-    parser_copyout.add_argument('ARCH', help="D64 Image filename")
-    parser_copyout.add_argument('SRC', help="Source filename (to be read from"
+    parser_copyout.add_argument('arch', help="D64 Image filename")
+    parser_copyout.add_argument('src', help="Source filename (to be read from"
                                 " D64 image")
-    parser_copyout.add_argument('DST', help="Destination filename")
+    parser_copyout.add_argument('dst', help="Destination filename")
     parser_copyout.set_defaults(func=CALL_MAP['copyout'])
 
-    parser_rm.add_argument('ARCH', help="D64 Image filename")
-    parser_rm.add_argument('DST', help="File inside D64 image to be deleted")
+    parser_rm.add_argument('arch', help="D64 Image filename")
+    parser_rm.add_argument('dst', help="File inside D64 image to be deleted")
     parser_rm.set_defaults(func=CALL_MAP['rm'])
 
+    parser_mkdir.add_argument('arch', help="archive filename")
+    parser_mkdir.add_argument('dst', help="Directory name inside archive to "
+                              "be created")
+    parser_mkdir.set_defaults(func=CALL_MAP['mkdir'])
+
+    parser_run.add_argument('arch', help="archive filename")
+    parser_run.add_argument('dst', help="File to be executed")
+    parser_run.set_defaults(func=CALL_MAP['run'])
+
     args = parser.parse_args()
     return args.func(args)
 
 
 def no_parse():
-    """
-    Failsafe argument "parsing". Note, that it blindly takes positional
+    """Failsafe argument "parsing". Note, that it blindly takes positional
     arguments without checking them. In case of wrong arguments it will
-    silently exit
-    """
+    silently exit"""
     try:
-        if sys.argv[1] not in ('list', 'copyin', 'copyout', 'rm'):
+        if sys.argv[1] not in ('list', 'copyin', 'copyout', 'rm', 'mkdir',
+                               "run"):
             sys.exit(2)
     except IndexError:
         sys.exit(2)
 
     class Arg(object):
-        DST = None
-        SRC = None
-        ARCH = None
+        """Mimic argparse object"""
+        dst = None
+        src = None
+        arch = None
 
     arg = Arg()
 
     try:
-        arg.ARCH = sys.argv[2]
+        arg.arch = sys.argv[2]
         if sys.argv[1] in ('copyin', 'copyout'):
-            arg.SRC = sys.argv[3]
-            arg.DST = sys.argv[4]
-        elif sys.argv[1] == 'rm':
-            arg.DST = sys.argv[3]
+            arg.src = sys.argv[3]
+            arg.dst = sys.argv[4]
+        elif sys.argv[1] in ('rm', 'run', 'mkdir'):
+            arg.dst = sys.argv[3]
     except IndexError:
         sys.exit(2)
 
-    CALL_MAP[sys.argv[1]](arg)
+    return CALL_MAP[sys.argv[1]](arg)
 
 if __name__ == "__main__":
     LOG.debug("Script params: %s", str(sys.argv))
     try:
         from argparse import ArgumentParser
-        parse_func = parse_args
+        PARSE_FUNC = parse_args
     except ImportError:
-        parse_func = no_parse
+        PARSE_FUNC = no_parse
 
-    parse_func()
+    sys.exit(PARSE_FUNC())