Path: utzoo!attcan!uunet!dptechno!dave
From: dave@dptechno.UUCP (Dave Lee)
Newsgroups: comp.unix.internals
Subject: Re: shmat() & shmdt() questions.
Message-ID: <583@dptechno.UUCP>
Date: 19 Sep 90 17:58:52 GMT
References: <13782@hydra.gatech.EDU> <13783@hydra.gatech.EDU>
Reply-To: dave@dptechno.UUCP (Dave Lee)
Organization: D.P. Technology Corp. Camarillo California
Lines: 25

In article <13783@hydra.gatech.EDU> gt0178a@prism.gatech.EDU (BURNS,JIM) writes:
>in article <13782@hydra.gatech.EDU>, I write:
>>    myshmid = shmget (some-made-up-not-in-use-int-id, 4096, IPC_CREAT|600);
>                                               ^^^
>
>I suppose that should actually be 'long', as in 'key_t'. I actually
>normally use an ascii representation of a 4-char string (assuming
>key_t=long). E.g. - if I want the key to be 'phs1', I use '0x70687331'.


And just how is one supposed to know what is "not-in-use" ?, unless ofcourse,
you just happen to be in controll of all the sources to all programs that 
may ever run on your machine.

If everyone would use ftok(path,id)  (see stdipc(3C)) as recomended in the FM,
(and then document the path and id used), then selecting a key would have a 
lot less chance of colliding with other program uses.  Unless you really
want a private key, then use IPC_PRIVATE.

IMHO of course.

 
-- 
Dave Lee
uunet!dptechno!dave