Salir sin un traceback con el valor de retorno apropiado ante excepciones

diff --git a/taller/ejercicios/ej1-20082/tp.py b/taller/ejercicios/ej1-20082/tp.py
index 79c9b2c762818ab35f0ebcaf58335dd15f8156ac..05b1e6ffdff0c1434bc309fd33f7bc9d04c94168 100755 (executable)
--- a/taller/ejercicios/ej1-20082/tp.py
+++ b/taller/ejercicios/ej1-20082/tp.py
@@ -282,23 +282,54 @@ def decode_message(str, msg, indent_level=1):
 # Main
 ##########################################################################
 
-def main(*args):
+class MessageNotFoundError(Exception):
+       pass
+
+def main(schmfile, pbfile, msgname):
        msgs = [Message('int'), Message('string')] \
-                       + parse(file(args[0]).read())
+                       + parse(schmfile.read())
        check_types(msgs)
        print msgs
-       msg = search(msgs, args[1])
+       msg = search(msgs, msgname)
        if msg is None:
-               print "can't find message with name %s in %s" % (args[1],
-                               args[0])
-               return 7
-       pbfile = sys.stdin
-       if len(args) > 2:
-               pbfile = file(args[2])
+               raise MessageNotFoundError("can't find message %s" % msgname)
        decode_message(pbfile.read(), msg)
-       return 0
 
 if __name__ == '__main__':
        import sys
-       sys.exit(main(*sys.argv[1:]))
+       try:
+               schmfile = sys.argv[1]
+               msgname = sys.argv[2]
+       except:
+               print 'wrong usage'
+               sys.exit(1)
+       try:
+               schmfile = file(args[0])
+       except:
+               print "can't open schema file %s" % schmfile
+               sys.exit(2)
+       pbfile = sys.stdin
+       if len(sys.argv) > 3:
+               try:
+                       pbfile = file(sys.argv[3])
+               except:
+                       print "can't open pb file %s" % sys.argv[3]
+                       sys.exit(3)
+       try:
+               main(schmfile, pbfile, msgname)
+       except LexicError, e:
+               print e
+               sys.exit(4)
+       except ParserError, e:
+               print e
+               sys.exit(5)
+       except SemanticError, e:
+               print e
+               sys.exit(6)
+       except MessageNotFoundError, e:
+               print e
+               sys.exit(7)
+       except DecodeError, e:
+               print e
+               sys.exit(8)