Re: [PATCH 1/2] tools/lib/api/fs: Add procfs int read/write helpers

[Arnaldo Carvalho de Melo]

Em Tue, Feb 07, 2017 at 02:09:17AM +0100, Borislav Petkov escreveu:
> From: Borislav Petkov <bp@xxxxxxx>
> 
> Add helper functions to be able to read/write ints into proc files.
> 
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> ---
>  tools/lib/api/fs/fs.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>  tools/lib/api/fs/fs.h |  3 +++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
> index 4b6bfc43cccf..8e4b9fe18b75 100644
> --- a/tools/lib/api/fs/fs.c
> +++ b/tools/lib/api/fs/fs.c
> @@ -314,6 +314,22 @@ int filename__read_int(const char *filename, int *value)
>  	return err;
>  }
>  
> +int filename__write_int(const char *filename, int value)
> +{
> +	char line[64];
> +	int fd = open(filename, O_WRONLY), err = -1;
> +
> +	if (fd < 0)
> +		return -1;
> +
> +	snprintf(line, sizeof(int), "%d", value);
> +
> +	err = write(fd, line, strnlen(line, 64));
> +
> +	close(fd);
> +	return err;
> +}
> +
>  /*
>   * Parses @value out of @filename with strtoull.
>   * By using 0 for base, the strtoull detects the
> @@ -400,6 +416,32 @@ int procfs__read_str(const char *entry, char **buf, size_t *sizep)
>  	return filename__read_str(path, buf, sizep);
>  }
>  
> +int procfs__read_int(const char *entry, int *value)
> +{
> +	char path[PATH_MAX];
> +	const char *procfs = procfs__mountpoint();
> +
> +	if (!procfs)
> +		return -1;
> +
> +	snprintf(path, sizeof(path), "%s/%s", procfs, entry);
> +
> +	return filename__read_int(path, value);
> +}
> +
> +int procfs__write_int(const char *entry, int value)
> +{
> +	char path[PATH_MAX];
> +	const char *procfs = procfs__mountpoint();
> +
> +	if (!procfs)
> +		return -1;
> +
> +	snprintf(path, sizeof(path), "%s/%s", procfs, entry);
> +
> +	return filename__write_int(path, value);
> +}
> +
>  int sysfs__read_ull(const char *entry, unsigned long long *value)
>  {
>  	char path[PATH_MAX];
> diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
> index 6b332dc74498..095f25d4c70f 100644
> --- a/tools/lib/api/fs/fs.h
> +++ b/tools/lib/api/fs/fs.h
> @@ -28,9 +28,12 @@ FS(bpf_fs)
>  
>  
>  int filename__read_int(const char *filename, int *value);
> +int filename__write_int(const char *filename, int value);
>  int filename__read_ull(const char *filename, unsigned long long *value);
>  int filename__read_str(const char *filename, char **buf, size_t *sizep);
>  
> +int procfs__read_int(const char *entry, int *value);
> +int procfs__write_int(const char *entry, int value);
>  int procfs__read_str(const char *entry, char **buf, size_t *sizep);
>  
>  int sysctl__read_int(const char *sysctl, int *value);

Isn't sysctl__read_int() what you want?

See next patch...