Re: checkpatch guide for newbies

From: Bjorn Helgaas
Date: Tue Sep 24 2013 - 16:13:51 EST

On Tue, Sep 24, 2013 at 1:29 PM, Peter Senna Tschudin
<peter.senna@xxxxxxxxx> wrote:
> On Tue, Sep 24, 2013 at 7:26 PM, Alexander Holler <holler@xxxxxxxxxxxxx> wrote:
>>> On Mon, Sep 23, 2013 at 3:01 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>>> wrote:
>>>> Long Lines
>>>> Historically screens were 80 characters wide and it was annoying when
>>>> code went
>>>> over the edge. These days we have larger screens, but we keep the 80
>>>> character
>>>> limit because it forces us to write simpler code.
>> Sorry, but that just isn't true and never was. Having a line wide limit of
>> 80 characters while forcing tabs to be 8 characters long limits most code to
>> just 72 characters. And even less (max 64) inside constructs like if, for or
>> while.
>> The only outcome of that totally silly rule is that variable names will
>> become shorted to silly acronyms almost nobody does understand make code
>> unreadable.

In the context of a two-sentence paragraph, Dan's original text is
pithy and accurate. A Wikipedia article would deserve more

Obviously the skill of the programmer is the overwhelming factor, but
I think restricting the line length does help encourage simpler,
better-factored code. It's also part of the whole "it's better to be
consistent than to be better" thing. If 95% of the files in Linux use
80-character lines and the remainder use longer lines, it's just an
ongoing hassle for the reader.

>> I always feel like beeing in the IT stone age when programmers thought they
>> have to use variable names like a, b and c to save storage, memory or to
>> type less when reading linux kernel code.
> I was about to disagree because I've never seen variables named a, b
> or c, but I found that there are at least 2238 variables named a, b or
> c in linux-next. This is not good.

That is not self-evident. In many cases, e.g., loop iterators, simple
names are fine. Nothing is gained by renaming a loop counter from "a"
to "array_index." Simple names for simple things help the reader
focus on more important aspects of the code.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at