Re: [PATCH v3] close_range.2: Add _GNU_SOURCE and unistd.h to SYNOPSIS

[Alejandro Colomar <alx@kernel.org>]

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Hi Mark,

On Mon, Feb 12, 2024 at 01:07:04PM +0100, Mark Wielaard wrote:
> close_range is defined in unistd.h when _GNU_SOURCE is defined.
> The linux/close_range.h include file only defines the (linux specific)
> flags constants. The flags argument is an int, not an unsigned int, in
> the glibc wrapper. Use the close_range library call in the example code
> instead of syscall.
> 
> Fixes: 71a62d6c3c56 ("close_range.2: Glibc added a wrapper recently")
> Fixes: c2356ba085ed ("close_range.2: Glibc 2.34 has added a close_range() wrapper")
> 
> Reported-by: Alexandra Hájková <ahajkova@redhat.com>
> Signed-off-by: Mark Wielaard <mark@klomp.org>

Thanks for the patch!  I've tweaked it a little bit, and applied it:
<https://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git/commit/?h=contrib&id=9dc4cba62c1d19ff3aa02e062e4a0c03f5299182>

Have a lovely night!
Alex

> ---
>  man2/close_range.2 | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/man2/close_range.2 b/man2/close_range.2
> index 380a47365..53ee5524e 100644
> --- a/man2/close_range.2
> +++ b/man2/close_range.2
> @@ -11,10 +11,14 @@ Standard C library
>  .RI ( libc ", " \-lc )
>  .SH SYNOPSIS
>  .nf
> -.B #include <linux/close_range.h>
> +.BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
> +.B #include <unistd.h>
> +.P
> +.BR "#include <linux/close_range.h>" " /* Definition of " CLOSE_RANGE_* "
> +.BR "" "                                  constants */"
>  .P
>  .BI "int close_range(unsigned int " first ", unsigned int " last ,
> -.BI "                unsigned int " flags );
> +.BI "                int " flags );
>  .fi
>  .SH DESCRIPTION
>  The
> @@ -205,7 +209,6 @@ result from the calls to
>  #include <limits.h>
>  #include <stdio.h>
>  #include <stdlib.h>
> -#include <sys/syscall.h>
>  #include <unistd.h>
>  \&
>  /* Show the contents of the symbolic links in /proc/self/fd */
> @@ -259,7 +262,7 @@ main(int argc, char *argv[])
>  \&
>      printf("========= About to call close_range() =======\en");
>  \&
> -    if (syscall(SYS_close_range, 3, \[ti]0U, 0) == \-1) {
> +    if (close_range(3, \[ti]0U, 0) == \-1) {
>          perror("close_range");
>          exit(EXIT_FAILURE);
>      }
> -- 
> 2.39.3
> 

-- 
<https://www.alejandro-colomar.es/>
Looking for a remote C programming job at the moment.

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