Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: Tim Rentsch Newsgroups: comp.lang.c Subject: Re: Isn't that beauty ? (no it's not) Date: Mon, 23 Mar 2026 21:23:47 -0700 Organization: A noiseless patient Spider Lines: 39 Message-ID: <86ecl94zzg.fsf@linuxsc.com> References: <10otm7r$1ntrg$1@raubtier-asyl.eternal-september.org> <10ougtt$21vgj$1@dont-email.me> <10ouhm6$22rm2$1@raubtier-asyl.eternal-september.org> <10ouje5$21vgj$5@dont-email.me> <10oul1g$241b4$1@raubtier-asyl.eternal-september.org> <10ov73a$2bugo$3@dont-email.me> <10p03uu$2nho7$1@dont-email.me> <10p07kn$2pg89$1@dont-email.me> <%jVsR.22274$_l2.6511@fx40.iad> <8634207ssj.fsf@linuxsc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Date: Tue, 24 Mar 2026 04:23:53 +0000 (UTC) Injection-Info: dont-email.me; posting-host="49275a8acb80bae5953bf00d88b0bbe4"; logging-data="774486"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1879RQCVM04pX6yQ9EmQpDnYEOeeigQJy0=" User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.4 (gnu/linux) Cancel-Lock: sha1:Hj40FFyH7Stt+cJcQkObgbKJZ1o= sha1:MZK8PfgIp8GKNY9gLnOAZ3SF6q4= Xref: csiph.com comp.lang.c:397170 scott@slp53.sl.home (Scott Lurndal) writes: > Tim Rentsch writes: >> scott@slp53.sl.home (Scott Lurndal) writes: >>> scott@slp53.sl.home (Scott Lurndal) writes: >>>> DFS writes: [...] >>>>> Why are you allowed to malloc size 0? >>>> >>>> "If the size of the space requested is 0, the behavior is >>>> implementation-defined: either a null pointer shall be returned, >>>> or the behavior shall be as if the size were some non-zero value, >>>> except that the behavior is undefined if the returned pointer is >>>> used to access an object." >>>> >>>> https://pubs.opengroup.org/onlinepubs/9799919799/functions/malloc.html >>> >>> IIRC, this caveat was added due to differences in the malloc(3) >>> implementations for System V Unix and BSD Unix. >> >> That sounds right, except I might say "put in" rather than "added" >> since as best I can determine that allowance was present in the >> earliest drafts of the C standard and POSIX discussions. >> >> Note that malloc() is not mentioned in K&R, and apparently was >> added to AT&T Unix in Unix V7. The timing on that was about the >> same time as the first BSD Unix. > > Right. K&R 1st Ed. defined a 'morecore' function based on sbrk. Ahh, I missed that. So it does. > K&R 2nd Ed. (ANSI) added malloc. Presumably malloc() was included in the early standard efforts well before K&R 2, which came out in 1988 IIRC. The early standardization work started in 1982 or 1983 IIANM, and malloc() had already been available since 1979, as both AT&T Unix V7 and BSD Unix were available at that time.