Path: utzoo!attcan!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.lang.c
Subject: Re: Life after free?
Keywords: free malloc
Message-ID: <1990Sep28.232247.24199@virtech.uucp>
Date: 28 Sep 90 23:22:47 GMT
References: <quan.654410256@sol> <606@oglvee.UUCP>
Reply-To: cpcahil@virtech.UUCP (Conor P. Cahill)
Organization: Virtual Technologies Inc., Sterling VA
Lines: 29

In article <606@oglvee.UUCP> norm@oglvee.UUCP (Norman Joseph) writes:
>In <quan.654410256@sol> quan@sol.surv.utas.oz (Stephen Quan) writes:
>
>>char *funny(ch)
>>char ch;
>>{
>>  char *tmp;
>>  [...]
>>  return tmp;
>>}
>
>No, but I -do- have a comment on returning tmp at all.  The storage
>class in the declaration of tmp defaults to "auto".  This gives the

However, if tmp is a pointer and you return the value contained in 
the pointer, who cares about tmp.  It is just used during the 
exection of the function.  The fact that tmp is no longer a valid
variable outside of this function will have no effect on the
availability of the data at the malloc'd region that tmp pointed to 
while it existed.

Note that I am NOT saying that you can free(tmp) and then return it.  If
the free was not there, the use of tmp would be totally correct.


-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170