Stylistic questions on UNIX C coding.
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From: io_x on 6 Mar 2010 15:37 "io_x" <a(a)b.c.invalid> ha scritto nel messaggio news:4b8e25c6$0$824$4fafbaef(a)reader5.news.tin.it... > > "Poster Matt" <postermatt(a)no_spam_for_me.org> ha scritto nel messaggio > news:ujehn.44277$Ym4.21796(a)text.news.virginmedia.com... >> Hi, >> >> I've a few questions concerning style when programming C on UNIX systems. I >> don't want to look like an amateur. :) > > all code here came from the poster "Peter Nilsson" from > news:f6245590-e586-4cb0-88f8-37afcebe15d4(a)s25g2000prd.googlegroups.com > > that can not be seen in my monitor editor, > here too in the editor of the news > is better than my amatorish stile > #include <string.h> > #include <stdlib.h> > > char* replace2_search(size_t n, char* s, > char* p, size_t pz, > char* q, size_t qz ) > {char *f, *r; > size_t z; > if(pz==0 || !(f = strstr(s, p))) > {z= strlen(s); r= (char*) malloc(n+z+1); > if(r) > strcpy(r+n, s); > } > else > {z= f-s; > r= replace2_search(n+z+qz, f+pz, p, pz, q, qz); > if(r){memcpy(r+n, s, z); > memcpy(r+n+z, q, qz); > } > } > return r; > } char* replace2_search(size_t n, char* s, char* p, size_t pz, char* q, size_t qz ) {char *f, *r; size_t z; if(pz==0 || !(f = strstr(s, p))) {z= strlen(s); if(r= (char*) malloc(n+z+1)) strcpy(r+n, s); } else {z= f-s; if(r=replace2_search(n+z+qz, f+pz, p, pz, q, qz)) {memcpy(r+n, s, z); memcpy(r+n+z, q, qz);} } return r; } > char* replace2(char *s, char *p, char *q) > {if(s==0||p==0||q==0) return 0; > return replace2_search(0, s, p, strlen(p), q, strlen(q)); > } > > that can be seen in one aye shot > > > >
From: Nick Keighley on 7 Mar 2010 05:15 On 5 Mar, 22:29, la...(a)ludens.elte.hu (Ersek, Laszlo) wrote: > For example, Pascal has := for assignment and = for equality (IIRC :)). Even > in C, I started out with "x == 7". I was occasionally bitten by > "if (x = 7)" typos. I even went though the occaisional x == 3; somehow AutoPilot (the not very bright bit of the brain that handles the routine stuff like getting to work and writing code) had come up with the rule "in C we double up '=' symbols"
From: Nick Keighley on 7 Mar 2010 05:28 On 5 Mar, 17:31, Tim Streater <timstrea...(a)waitrose.com> wrote: > On 05/03/2010 16:04, Richard Heathfield wrote: > > This is C we're discussing, not English. It is folly to pretend that the > > rules of English apply to C. > > But Richard, you have to read the code in order to interpret it mentally > and decide whether it's correct or not, or how to amend it. I gave up on > Forth, Lisp, and regexps for just this reason. I guess by "read" you mean subvocalise. I can read Lisp without difficulty and regexps rather slowly. Never seriously tried Forth. I'm pretty sure I subvocalise because I've acquired some odd pronounciations for words that had been in my reading vocabulary longer than my spoken vocabulary. I think the subroutine that assigns sounds to unfamiliar words is fast but stupid.
From: Nick Keighley on 7 Mar 2010 05:33 On 5 Mar, 18:26, Seebs <usenet-nos...(a)seebs.net> wrote: > On 2010-03-05, Richard Heathfield <r...(a)see.sig.invalid> wrote: > > > This is C we're discussing, not English. It is folly to pretend that the > > rules of English apply to C. > > Actually, I'm not exactly talking about English. I'm talking about the > underlying cognitive structures English (and every other language) maps to. ah! A disciple of Chompsky.I didn't know it had been proven beyond doubt that such a Deep Structure existed > So far as I know, regardless of language, humans distinguish between the > topic and the comment (thanks to another poster for providing the > terminology). > > > Ignoring. Probably a minor thinko on his part, no big deal. > > Not a big deal, but oddly, somewhat related -- it's the kind of mistake that > shows up as a side-effect of added complexity. If you add enough parentheses > to an expression, people will start mismatching them or putting them in the > wrong places because they can't track them automatically anymore, or because > the automatic tracking fails. to write lisp you pretty well have to have support from your editor. I seem to nest stuff deeper than most people- maybe this is something computer programmers tend to do but lisp easily busts my internal stack. > For me, swapping the "natural" order of a comparison (I expect the "topic" > to be first) is one extra layer, similar to an indirection, extra set of > parentheses, or whatever. I don't know how common that is, but I'm pretty > sure it's not going to change in the forseeable future. I'll suffer the pain of an extra translation stage if I think it buys me much. In this case I'd rather have the test the "right" way round.
From: Rainer Weikusat on 7 Mar 2010 07:15
pete <pfiland(a)mindspring.com> writes: [...] > To count down through an array with N elements, I use > > size_t i = N; > > while (i-- != 0) { > array[i]; > } And you excuse for writing confusing code which requests that the machine does useless things is that software to work around you has already been developed, right? |