[PATCH 2/3] linux: use fd_to_filename instead of _fitoa_word in ttyname_r.

[Adhemerval Zanella]

On 03/05/2021 22:51, Érico Nogueira via Libc-alpha wrote:
> Simplifies the logic and makes intent clearer, while at the same time
> decreasing binary size.
> 
> On x86_64, dropped from 1883270 to 1883206, a 64 byte decrease.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/unix/sysv/linux/ttyname_r.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/ttyname_r.c b/sysdeps/unix/sysv/linux/ttyname_r.c
> index c1092d1695..fa1578fb64 100644
> --- a/sysdeps/unix/sysv/linux/ttyname_r.c
> +++ b/sysdeps/unix/sysv/linux/ttyname_r.c
> @@ -26,7 +26,7 @@
>  #include <string.h>
>  #include <stdlib.h>
>  
> -#include <_itoa.h>
> +#include <fd_to_filename.h>
>  
>  #include "ttyname.h"
>  
> @@ -92,7 +92,7 @@ getttyname_r (char *buf, size_t buflen, const struct stat64 *mytty,
>  int
>  __ttyname_r (int fd, char *buf, size_t buflen)
>  {
> -  char procname[30];
> +  struct fd_to_filename filename;
>    struct stat64 st, st1;
>    int dostat = 0;
>    int doispty = 0;
> @@ -122,9 +122,7 @@ __ttyname_r (int fd, char *buf, size_t buflen)
>      return errno;
>  
>    /* We try using the /proc filesystem.  */
> -  *_fitoa_word (fd, __stpcpy (procname, "/proc/self/fd/"), 10, 0) = '\0';
> -
> -  ssize_t ret = __readlink (procname, buf, buflen - 1);
> +  ssize_t ret = __readlink (__fd_to_filename (fd, &filename), buf, buflen - 1);
>    if (__glibc_unlikely (ret == -1 && errno == ENAMETOOLONG))
>      {
>        __set_errno (ERANGE);
>