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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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