1 /* Copyright (C) 2005, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
27 #include <kernel-features.h>
30 /* Make a symbolic link to FROM named TO relative to TOFD. */
32 symlinkat (from, tofd, to)
40 # ifndef __ASSUME_ATFCTS
41 if (__have_atfcts >= 0)
44 result = INLINE_SYSCALL (symlinkat, 3, from, tofd, to);
45 # ifndef __ASSUME_ATFCTS
46 if (result == -1 && errno == ENOSYS)
54 #ifndef __ASSUME_ATFCTS
57 if (tofd != AT_FDCWD && to[0] != '/')
59 size_t tolen = strlen (to);
60 static const char procfd[] = "/proc/self/fd/%d/%s";
61 /* Buffer for the path name we are going to use. It consists of
62 - the string /proc/self/fd/
63 - the file descriptor number
64 - the file name provided.
65 The final NUL is included in the sizeof. A bit of overhead
66 due to the format elements compensates for possible negative
68 size_t buflen = sizeof (procfd) + sizeof (int) * 3 + tolen;
69 buf = __alloca (buflen);
71 __snprintf (buf, buflen, procfd, tofd, to);
75 INTERNAL_SYSCALL_DECL (err);
77 result = INTERNAL_SYSCALL (symlink, err, 2, from, to);
79 if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
81 __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), tofd, buf);