Re: [PATCH] memusage.1: Use sizeof consistently

Michael Kerrisk (man-pages)
2020-09-04T08:20:13Z

Hello Alex,

On 9/3/20 12:23 PM, Alejandro Colomar wrote:
> Hi Michael,
>
> Continuing with the series, this is the first of the last set of
> patches: (2).1 as numbered in previous emails.

I must admit that I don't care too much either way on this.
That is to say, I'm not sure one way is any clearer than
the other. However, I have applied the patch.

In passing, I note that there is a clarity issue that I do
find more significant though: the repeated calculations in
the malloc() and printf() calls. So I changed that:
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=15fc4aab1f22c2d4f62ab7f74bbb844942708633

Thanks,

Michael

> ------------------------------------------------------------------------
>>From ad5f958ed68079791d6e35f9d70ca5ec2a72c43b Mon Sep 17 00:00:00 2001
> From: Alejandro Colomar <colomar.6.4.3@gmail.com>
> Date: Thu, 3 Sep 2020 12:11:18 +0200
> Subject: [PATCH] memusage.1: Use sizeof consistently
>
> Use ``sizeof`` consistently through all the examples in the following
> way:
>
> - Use the name of the variable instead of its type as argument for
> ``sizeof``.
>
> Rationale:
> https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
>
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
> ---
> man1/memusage.1 | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/man1/memusage.1 b/man1/memusage.1
> index fa1987c79..a03468442 100644
> --- a/man1/memusage.1
> +++ b/man1/memusage.1
> @@ -247,8 +247,8 @@ main(int argc, char *argv[])
> int i, j;
> int *p;
>
> - printf("malloc: %zd\en", sizeof(int) * 100);
> - p = malloc(sizeof(int) * 100);
> + printf("malloc: %zd\en", sizeof(*p) * 100);
> + p = malloc(sizeof(*p) * 100);
>
> for (i = 0; i < CYCLES; i++) {
> if (i < CYCLES / 2)
> @@ -256,11 +256,11 @@ main(int argc, char *argv[])
> else
> j--;
>
> - printf("realloc: %zd\en", sizeof(int) * (j * 50 + 110));
> - p = realloc(p, sizeof(int) * (j * 50 + 100));
> + printf("realloc: %zd\en", sizeof(*p) * (j * 50 + 110));
> + p = realloc(p, sizeof(*p) * (j * 50 + 100));
>
> - printf("realloc: %zd\en", sizeof(int) * ((j+1) * 150 + 110));
> - p = realloc(p, sizeof(int) * ((j + 1) * 150 + 110));
> + printf("realloc: %zd\en", sizeof(*p) * ((j+1) * 150 + 110));
> + p = realloc(p, sizeof(*p) * ((j + 1) * 150 + 110));
> }
>
> free(p);
>

--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/