First C Program

Hi Barbara



Thank you for your kind information, much appreciated.

I am afraid I have been tempted by the dark side.

I admit I got the code from an IBM book.

ILE C for AS/400(R) Programmer's Guide Version 4 pp160



I am still learning how to apply Paul Contes guidelines.

Hopefully I will keep to the light.



Frank

*Subject: Re: First C program

*From: Barbara Morris <bmorris@xxxxxxxxxx>

*Date: Wed, 02 Apr 2014 15:52:03 -0400

On 2014-04-02 02:32, frank kolmann wrote:

...

1. Don't use = in an if statement expression, unless it is

absolutely necessary.

Frank, this code seems to violate that guideline.

if ((pf = _Ropen(PFILENAME, "rr")) EQ NULL)

{ printf("can't open file %s\n", PFILENAME); exit(1); }

I think it's a very good guideline.

I would code that like this. (I'll go along with the EQ ...)

pf = _Ropen(PFILENAME, "rr");

if (pf EQ NULL)

...

I would also spread out the code under the "if".

I think it's too easy to miss the exit statement

when the printf and exit are on the same line.

I also think it's easier to see exactly what code

is conditioned by the "if" when the curly braces

are coded on their own lines.

pf = _Ropen(PFILENAME, "rr");

if (pf EQ NULL)

{

printf("can't open file %s\n", PFILENAME);

exit(1);

}

This code takes up a few more lines than yours,

but I find it much more readable-at-a-glance.

If you want to collapse the code to make it easier to follow
the whole program, you could put all the opens into a separate function.