Jack's module for parsing UNIX mailbox files

diff --git a/Lib/mailbox.py b/Lib/mailbox.py
new file mode 100755 (executable)
index 0000000..b7a5598
--- /dev/null
+++ b/Lib/mailbox.py
@@ -0,0 +1,137 @@
+#
+# A class to hand a unix-style or mmdf-style mailboxes
+#
+# Jack Jansen, CWI, March 1994.
+#
+import rfc822
+
+class _Mailbox:
+       def __init__(self, fp):
+               self.fp = fp
+               self.seekp = 0
+
+       def seek(self, pos):
+               self.seekp = pos
+
+       def next(self):
+               while 1:
+                       self.fp.seek(self.seekp)
+                       try:
+                               self._search_start()
+                       except EOFError:
+                               self.seekp = self.fp.tell()
+                               return None
+                       start = self.fp.tell()
+                       self._search_end()
+                       self.seekp = stop = self.fp.tell()
+                       if start <> stop:
+                               break
+               return rfc822.Message(_Subfile(self.fp, start, stop))
+
+class _Subfile:
+       def __init__(self, fp, start, stop):
+               self.fp = fp
+               self.start = start
+               self.stop = stop
+               self.pos = self.start
+
+       def read(self, *args):
+               if self.pos >= self.stop:
+                       return ''
+               if args == ():
+                       length = self.stop - self.pos
+               else:
+                       length = args[0]
+               self.fp.seek(self.pos)
+               self.pos = self.pos + length
+               return self.fp.read(length)
+
+       def readline(self, *args):
+               if self.pos >= self.stop:
+                       return ''
+               if args == ():
+                       length = self.stop - self.pos
+               else:
+                       length = args[0]
+               self.fp.seek(self.pos)
+               data = self.fp.readline(length)
+               if len(data) < length:
+                       length = len(data)
+               self.pos = self.pos + length
+               return data
+
+       def tell(self):
+               return self.pos - self.start
+
+       def seek(self, pos):
+               self.pos = pos + self.start
+
+       def close(self):
+               pass
+
+class UnixMailbox(_Mailbox):
+       def _search_start(self):
+               while 1:
+                       line = self.fp.readline()
+                       if not line:
+                               raise EOFError
+                       if line[:5] == 'From ':
+                               return
+
+       def _search_end(self):
+               while 1:
+                       pos = self.fp.tell()
+                       line = self.fp.readline()
+                       if not line:
+                               return
+                       if line[:5] == 'From ':
+                               self.fp.seek(pos)
+                               return
+
+class MmdfMailbox(_Mailbox):
+       def _search_start(self):
+               while 1:
+                       line = self.fp.readline()
+                       if not line:
+                               raise EOFError
+                       if line[:5] == '\001\001\001\001\n':
+                               return
+
+       def _search_end(self):
+               while 1:
+                       pos = self.fp.tell()
+                       line = self.fp.readline()
+                       if not line:
+                               return
+                       if line == '\001\001\001\001\n':
+                               self.fp.seek(pos)
+                               return
+
+if __name__ == '__main__':
+       import posix
+       import time
+       import sys
+       import string
+       mbox = '/usr/mail/'+posix.environ['USER']
+       fp = open(mbox, 'r')
+       mb = UnixMailbox(fp)
+       msgs = []
+       while 1:
+               msg = mb.next()
+               if not msg:
+                       break
+               msgs.append(msg)
+       if len(sys.argv) > 1:
+               num = string.atoi(sys.argv[1])
+               print 'Message %d body:'%num
+               msg = msgs[num-1]
+               msg.rewindbody()
+               sys.stdout.write(msg.fp.read())
+               sys.exit(0)
+       print 'Mailbox',mbox,'has',len(msgs),'messages:'
+       for msg in msgs:
+               f = msg.getheader('from')
+               s = msg.getheader('subject')
+               d = (msg.getheader('date'))
+               print '%20.20s   %18.18s   %-30.30s'%(f, d[5:], s)
+