Added proctect bits, configuration variables

uc1541

@@ -6,9 +6,18 @@ This extfs provides an access to disk image files for the Commodore
 VIC20/C64/C128. It requires the utility c1541 that comes bundled with Vice,
 the emulator for the VIC20, C64, C128 and other computers made by Commodore.
 
+Changelog:
+    1.2 Added configuration env variables: UC1541_VERBOSE and UC1541_HIDE_DEL.
+        First one, if set to any value, will cause that error messages from
+        c1541 program will be redirected as a failure messages visible in MC.
+        The other variable, when set to any value, cause "del" entries to be
+        not shown in the lister.
+    1.1 Added protect bits, added failsafe for argparse module
+    1.0 Initial release
+
 Author: Roman 'gryf' Dobosz <gryf73@gmail.com>
-Date: 2012-08-07
+Date: 2012-08-16
-Version: 1.0
+Version: 1.2
 Licence: BSD
 """
 
@@ -16,7 +25,6 @@ import sys
 import re
 import os
 from subprocess import Popen, PIPE
-from argparse import ArgumentParser
 
 
 class Uc1541(object):
@@ -29,6 +37,8 @@ class Uc1541(object):
         self.arch = archname
         self.out = ''
         self.err = ''
+        self._verbose = os.getenv("UC1541_VERBOSE", False)
+        self._hide_del =  os.getenv("UC1541_HIDE_DEL", False)
 
     def list(self):
         """
@@ -43,14 +53,20 @@ class Uc1541(object):
             if Uc1541.PRG.match(line):
                 blocks, fname, ext, rw = Uc1541.PRG.match(line).groups()
 
+                if ext == 'del' and self._hide_del:
+                    continue
+
                 if '/' in fname:
                     fname = fname.replace('/', '\\')
 
-                rw = rw.strip() and "-" or "w"
+                if ext == 'del':
+                    perms = "----------"
+                else:
+                    perms = "-r%s-r--r--" % (rw.strip() and "-" or "w")
 
-                #fname = ".".join([fname, ext])
+                fname = ".".join([fname, ext])
-                sys.stdout.write("-r%s-r--r--   1 %-8d %-8d %8d Jan 01 1980"
+                sys.stdout.write("%s   1 %-8d %-8d %8d Jan 01 1980"
-                                 " %s\n" % (rw, os.getuid(), os.getgid(),
+                                 " %s\n" % (perms, os.getuid(), os.getgid(),
                                             int(blocks) * 256, fname))
         return 0
 
@@ -62,12 +78,15 @@ class Uc1541(object):
         if not self._call_command('delete', dst=dst):
             return self._show_error()
 
-        # In case of error during removing, ERRORCODE is sent to stdout
+        # During removing, a message containing ERRORCODE is sent to stdout
-        # instead of stderr AND 'ERRORCODE 1' means: # 'everything fine'
+        # instead of stderr. Everything other than 'ERRORCODE 1' (which means:
-        if '\nERRORCODE 1\n' in self.out:
+        # 'everything fine') is actually a failure. In case of verbose error
-            return 0
+        # output it is needed to copy self.out to self.err.
+        if '\nERRORCODE 1\n' not in self.out:
+            self.err = self.out
+            return self._show_error()
 
-        sys.exit(self.out)
+        return 0
 
     def copyin(self, dst, src):
         """
@@ -102,8 +121,8 @@ class Uc1541(object):
         if "\\" in fname:
             fname = fname.replace('\\', '/')
 
-        #if fname.lower().endswith('.prg') or fname.lower().endswith('.del'):
+        if fname.lower().endswith('.prg') or fname.lower().endswith('.del'):
-        #    fname = fname[:-4]
+            fname = fname[:-4]
 
         return fname
 
@@ -111,7 +130,10 @@ class Uc1541(object):
         """
         Pass out error output from c1541 execution
         """
-        sys.exit(self.err)
+        if self._verbose:
+            sys.exit(self.err)
+        else:
+            sys.exit(1)
 
     def _call_command(self, cmd, src=None, dst=None):
         """
@@ -133,7 +155,16 @@ class Uc1541(object):
         return not self.err
 
 
-if __name__ == "__main__":
+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)}
+
+
+def parse_args():
+    """
+    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 "
@@ -145,25 +176,63 @@ if __name__ == "__main__":
     parser_rm = subparsers.add_parser('rm', help="Delete file from D64 image")
 
     parser_list.add_argument('ARCH', help="D64 Image filename")
-    parser_list.set_defaults(func=lambda a: Uc1541(a.ARCH).list())
+    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 "
                                "written into D64 image)")
-    parser_copyin.set_defaults(func=lambda a: Uc1541(a.ARCH). \
+    parser_copyin.set_defaults(func=CALL_MAP['copyin'])
-            copyin(a.SRC, a.DST))
 
     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.set_defaults(func=lambda a: Uc1541(a.ARCH). \
+    parser_copyout.set_defaults(func=CALL_MAP['copyout'])
-            copyout(a.SRC, a.DST))
 
     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=lambda a: Uc1541(a.ARCH).rm(a.DST))
+    parser_rm.set_defaults(func=CALL_MAP['rm'])
 
     args = parser.parse_args()
-    args.func(args)
+    return args.func(args)
+
+def no_parse():
+    """
+    Failsafe argument "parsing". Note, that it blindly takes positional
+    arguments without checking them. In case of wrong arguments it will
+    silently exit
+    """
+    try:
+        if sys.argv[1] not in ('list', 'copyin', 'copyout', 'rm'):
+            sys.exit(2)
+    except IndexError:
+        sys.exit(2)
+
+    class Arg(object):
+        DST = None
+        SRC = None
+        ARCH = None
+
+    arg = Arg()
+
+    try:
+        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]
+    except IndexError:
+        sys.exit(2)
+
+    CALL_MAP[sys.argv[1]](arg)
+
+if __name__ == "__main__":
+    try:
+        from argparse import ArgumentParser
+        parse_func = parse_args
+    except ImportError:
+        parse_func = no_parse
+
+    parse_func()