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From: Arkady Belousov <ark@munic.msk.su>
Subject: Re: What's the best language to start with? [was: Re: Should I learn
 C or Pascal?]
Date: 1996/09/03
Message-ID: <322D08A6.7AC0@munic.msk.su>#1/1
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Date: 1996-09-03T00:00:00+00:00
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Hello!

Richard A. O'Keefe wrote:

> Consider
>         char *dupcat(char const *a, char const *b) {
>             char *result = malloc(strlen(a) + strlen(b) + 1);
>             assert(result != 0);
>             memcpy(result, a, strlen(a));
>             memcpy(result + strlen(a), b, strlen(b));
>             memcpy(result + strlen(a) + strlen(b), "", 1);
>             return result;
>         }
> I repeat, this is NOT the way I would normally write it.
> I contend that it is _inefficient_ but not "stupid".
> If a malicious (and not strictly conforming) signal handler smashes
> NBTS(a) or NBTS(b), then you have worse problems than just possible
> changes to strlen().  Manually saving the numbers won't protect you
> from the fact that the null-terminated-byte-strings have changed,
> so that the function result (as an NBTS) is not the concatenation
> of its NBTS arguments.

     For ease controlling such situation standard have "volatile"
keyword. So you are right, I think.