Recommended style

[Kelvin Moss]

Hi all,

Which is the recommended style in production code for the following -

....
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
....
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
....
}

Thanks.

[Alex]

how about

if((fp=fopen(fi lename,"mode")) ==NULL)
{
//failed
}

"Kelvin Moss" <km**********@y ahoo.com> wrote in message
news:11******** **************@ c13g2000cwb.goo glegroups.com.. .

Hi all,

Which is the recommended style in production code for the following -

...
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
...
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
...
}

Thanks.

[Artie Gold]

Kelvin Moss wrote:

Hi all,

Which is the recommended style in production code for the following -

...
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
...
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
...
}

Thanks.

I think in a case like this, either one would be just fine; it's just
the case that the former is more explicit, while the latter employs a
well-known C idiom.

You might want to keep it consistent in a project -- but either choice
is sufficiently transparent. (I prefer the second, but that's pure opinion.)

HTH,
--ag

--
Artie Gold -- Austin, Texas
http://it-matters.blogspot.com (new post 12/5)
http://www.cafepress.com/goldsays

[The Dragon]

Alex wrote:

how about

if((fp=fopen(fi lename,"mode")) ==NULL)
{
//failed
}

or, conversely:

if ( NULL == ( fp = fopen( filename, mode ) ) ) {
/* Failed */
}

Constants going on the left makes the C compiler bitch about =
instead of == which is a common programmer error that generally
takes a long time to find during runtime debugging ;}

Same with below:

fp = fopen( filename, mode );
if ( NULL == fp ) {
/* failed */
}

if ( !fp ) doesn't require constants on the left, since ! is a
unary logic operator.

-- The Dragon

Hi all,

Which is the recommended style in production code for the following -

...
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
...
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
...
}

Thanks.

[Martin Ambuhl]

Kelvin Moss wrote:

Hi all,

Which is the recommended style in production code for the following -

...
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
...
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
...
}

Anyone who tells you that either of these is "recommende d style" except
with reference to your local coding standards is blowing smoke.

For what it's worth, I prefer
if (!(fp = fopen("xyz.txt" ,"r"))) {
/* handle error */
}

[infobahn]

Kelvin Moss wrote:

Hi all,

Which is the recommended style in production code for the following -

....
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
....
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
....
}

It depends who you ask.

If your employer/client/whatever doesn't impose a house style, decide
which you think is more logical, and use it.

Some people (including myself) argue that a pointer is not a boolean
variable and should not be treated like one. Other people argue
that !fp is just a shorthand for == 0, and so there's no harm in
using if(!fp), and if(fp == NULL) is only for people who love typing.

I hate typing, but I would rather type a few more characters if the
result is code which I find easier to maintain.

Personally, I use this:

fp = fopen(fn, fmode);
if(fp != NULL)
{
rc = foo(fp);
fclose(fp);
}
else
{
deal with the error
}

but there is no "right" answer to this question.

[Emmanuel Delahaye]

Kelvin Moss wrote on 30/12/04 :

Which is the recommended style in production code for the following -

...
fp = fopen("xyz.txt" , "r");
if (fp == NULL) {
...
}

OR
fp = fopen("xyz.txt" , "r");
if (!fp) {
...
}

Thanks.

The first one. No option!

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

"Clearly your code does not meet the original spec."
"You are sentenced to 30 lashes with a wet noodle."
-- Jerry Coffin in a.l.c.c++

[Emmanuel Delahaye]

Alex wrote on 30/12/04 :

how about

if((fp=fopen(fi lename,"mode")) ==NULL)
{
//failed
}

Certainely not. Ugly, hard to read, hard to maintain.

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

"C is a sharp tool"

[Emmanuel Delahaye]

infobahn wrote on 30/12/04 :

Personally, I use this:

fp = fopen(fn, fmode);
if(fp != NULL)
{
rc = foo(fp);
fclose(fp);
}
else
{
deal with the error
}

Agreed.

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

"Clearly your code does not meet the original spec."
"You are sentenced to 30 lashes with a wet noodle."
-- Jerry Coffin in a.l.c.c++

[Kelvin Moss]

infobahn wrote:

Kelvin Moss wrote: Some people (including myself) argue that a pointer is not a boolean
variable and should not be treated like one. Other people argue
that !fp is just a shorthand for == 0, and so there's no harm in
using if(!fp), and if(fp == NULL) is only for people who love typing.
I too belong to the same school of thought. In fact in my whole code I
have used this syntax.

I hate typing, but I would rather type a few more characters if the
result is code which I find easier to maintain.

Personally, I use this:

fp = fopen(fn, fmode);
if(fp != NULL)
{
rc = foo(fp);
fclose(fp);
}
else
{
deal with the error
}

but there is no "right" answer to this question.

I too feel that doing this makes the code more readable.

Thanks.