Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!uwvax!uwmacc!hobbes!root From: root@hobbes.UUCP (John Plocher) Newsgroups: comp.unix.xenix Subject: Microport Users' Group Bug List (LONG) Message-ID: <157@hobbes.UUCP> Date: Thu, 23-Jul-87 14:09:55 EDT Article-I.D.: hobbes.157 Posted: Thu Jul 23 14:09:55 1987 Date-Received: Sat, 25-Jul-87 11:55:15 EDT References: <166@qetzal.UUCP> Reply-To: root@hobbes.UUCP (John Plocher) Followup-To: comp.unix.xenix Organization: U of Wisconsin - Madison Spanish Department Lines: 35 +---- (Robert White) writes the following in article <166@qetzal.UUCP> ---- | | Compiler problems -- specifically: | | 10. Passing (char *) NULL to a function in a large model program can cause | a core dump/program abort. This makes some programs, which work under | small model, fail under large for no apparent reason. Symptom is that | the dump occurs between the function call and the first executable | instruction in the function itself (usually a Mem fault or Segv) | This blows up a LOT of things, including printf("%s", (char *) NULL) | (or equivalent). +---- WRONG! Passing the NULL pointer is not what is wrong! What IS wrong is the ASSUMPTION that the data stored at location NULL is anything useful! printf("%s", (char *) NULL); says print the string at address 0. This happens to work on a VAX because that machine SPECIFICALLY has set things up so that the contents of location 0 is 0. This bad coding practice hits owners of Sun machines as well and is NOT a compiler bug. +---- | 17. Along the same line, so is 'ps' with no arguments (produces nothing, | should show your processes.) 'ps' with arguments works fine. New problem | with 2.2.2. +---- Try removing the file /etc/ps_data This will make ps work again. ps_data is a cache of namelist info from /unix; when you changed versions, you forgot to invalidate the 'cache'. FLAME: ps should check the dates on /unix and on /etc/ps_data and do the invalidation itself! -- John Plocher uwvax!geowhiz!uwspan!plocher plocher%uwspan.UUCP@uwvax.CS.WISC.EDU