Date: Tue, 31 Mar 2009 08:54:17 -0700 From: Gary Kline <kline@thought.org> To: Polytropon <freebsd@edvax.de> Cc: FreeBSD Mailing List <freebsd-questions@freebsd.org> Subject: Re: Why?? (prog question) Message-ID: <20090331155416.GA8590@thought.org> In-Reply-To: <20090331112122.ae329221.freebsd@edvax.de> References: <20090331025726.GA10888@thought.org> <20090331112122.ae329221.freebsd@edvax.de>
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On Tue, Mar 31, 2009 at 11:21:22AM +0200, Polytropon wrote:
> I don't want to start a "style debate", but forgive me the
> following annotations:
>
> 1. Use the tab character for indentation. You can set its
> length with your favourite editor (e. g. mcedit: F9,
> Options, General; joe: ^TD). Don't waste with spaces.
Ja, been doing this since 1978. Does anybody hit space-key
8 times!?
>
> 2. The main() function should be declared as
> int main(int argc, char *argv[])
> or
> int main(int argc, char **argv)
> Note that it's returning (int). Use this functionality.
I've come to prefer the *char argv[] ... I didn't use the formal int
return because this was supposed throwaway code. (Going on years now
tho, so ... my-bad.)
>
> 3. In case of errors (e. g. incorrect number of parameters)
> use fprintf() to stderr, or perror() with the builtin
> error handling (e. g. for "file not found" by fopen()).
>
> 4. Use the predefined return codes, don't hardcode them.
> FreeBSD has EXiT_SUCCESS and EXIT_FAILURE, they're for
> maximum compatibility (such as with Linux). There are
> more exit codes for differentiation, but they're specific
> to FreeBSD, as far as I know.
This I did not know. I have a prefab include file with a bunch
of my own similar #defines. Wow, great!
>
> 5. This is highly debatable: Use a good style for { and }.
>
Well, you're using the K&R { }; but for me, the "Ingres"
style [[ yes, it was invented by someone else ]] gets my vote.
I scan
{
and
}
more easily. 6 of one, half-dozen of another... .
> 6. Use delimiters around operators, e. g. buf[strlen(buf) - 1]
> instead of buf[strlen(buf)-1]; increases readability.
>
Yup.
> Here is the program again, with some stylistic modifications
> and the "correct" (read: recommended, usual) exit code handling:
>
>
I'll swipe this. I use this code with openoffice and abiword
because I compose with vi; but I almost always forget to run
my text thru joinlines and have to quit the word processor, run
jlines <foo> bar; mv bar foo; then restart the word processor.
I figure that I've spend several centuries of my lifetime messing
with jlines, so i'm overdue for doing it right....
gary
>
>
> /*
> * simple prog to join all | very nearly all lines of a text file
> * that make up one paragraph into one LONG line.
> *
> * paragraphs are delimiated by a single \n break.
> */
>
> #include <stdio.h>
> #include <string.h>
> #include <stdlib.h>
>
> int main(int argc, char *argv[])
> {
> char buf[65536];
>
>
> if(argc == 1) {
> fprintf(stderr, "Usage: %s < file > newfile\n", argv[0]);
> exit(EXIT_FAILURE);
> }
>
> while (fgets(buf, sizeof buf, stdin)) {
> if(*buf == '\n') {
> fprintf(stdout, "\n\n");
> } else {
> buf[strlen(buf) - 1] = ' ';
> fputs(buf, stdout);
> }
> }
>
> return EXIT_SUCCESS;
> }
>
>
>
>
>
> Note that compiling with -Wall (always a good option) doesn't
> show any warning.
>
>
>
> I read my advices again... makes me sound sooooo old! :-)
>
>
>
> --
> Polytropon
> From Magdeburg, Germany
> Happy FreeBSD user since 4.0
> Andra moi ennepe, Mousa, ...
--
Gary Kline kline@thought.org http://www.thought.org Public Service Unix
http://jottings.thought.org http://transfinite.thought.org
The 2.41a release of Jottings: http://jottings.thought.org/index.php
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