int
linkat (int fd1, char const *file1, int fd2, char const *file2, int flag)
{
if (flag & ~AT_SYMLINK_FOLLOW)
{
errno = EINVAL;
return -1;
}
return at_func2 (fd1, file1, fd2, file2,
flag ? link_follow : link_immediate);
}
int
rpl_linkat (int fd1, char const *file1, int fd2, char const *file2, int flag)
{
if (flag & ~AT_SYMLINK_FOLLOW)
{
errno = EINVAL;
return -1;
}
# if LINKAT_TRAILING_SLASH_BUG
/* Reject trailing slashes on non-directories. */
{
size_t len1 = strlen (file1);
size_t len2 = strlen (file2);
if ((len1 && file1[len1 - 1] == '/')
|| (len2 && file2[len2 - 1] == '/'))
{
/* Let linkat() decide whether hard-linking directories is legal.
If fstatat() fails, then linkat() should fail for the same reason;
if fstatat() succeeds, require a directory. */
struct stat st;
if (fstatat (fd1, file1, &st, flag ? 0 : AT_SYMLINK_NOFOLLOW))
return -1;
if (!S_ISDIR (st.st_mode))
{
errno = ENOTDIR;
return -1;
}
}
}
# endif
if (!flag)
{
int result = linkat (fd1, file1, fd2, file2, flag);
# if LINKAT_SYMLINK_NOTSUP
/* OS X 10.10 has linkat() but it doesn't support
hardlinks to symlinks. Fallback to our emulation
in that case. */
if (result == -1 && (errno == ENOTSUP || errno == EOPNOTSUPP))
return at_func2 (fd1, file1, fd2, file2, link_immediate);
# endif
return result;
}
/* Cache the information on whether the system call really works. */
{
static int have_follow_really; /* 0 = unknown, 1 = yes, -1 = no */
if (0 <= have_follow_really)
{
int result = linkat (fd1, file1, fd2, file2, flag);
if (!(result == -1 && errno == EINVAL))
{
have_follow_really = 1;
return result;
}
have_follow_really = -1;
}
}
return linkat_follow (fd1, file1, fd2, file2);
}
