1/* Query filename corresponding to an open FD. Linux version.
2 Copyright (C) 2001-2019 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <sys/stat.h>
20#include <string.h>
21#include <_itoa.h>
22
23#define FD_TO_FILENAME_SIZE ((sizeof ("/proc/self/fd/") - 1) \
24 + (sizeof ("4294967295") - 1) + 1)
25
26static inline const char *
27fd_to_filename (unsigned int fd, char *buf)
28{
29 *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
30
31 /* We must make sure the file exists. */
32 struct stat64 st;
33 if (__lxstat64 (_STAT_VER, buf, &st) < 0)
34 /* /proc is not mounted or something else happened. */
35 return NULL;
36 return buf;
37}
38