/// <summary>Linux specific implementation of <see cref="IO.GetFilePermissionsForFilePath"/> </summary>
internal static int GetFilePermissionsForFilePath(string path, bool followSymlink)
{
var stat = new stat_buf();
int errorCode = StatFile(AT_FDCWD, path, followSymlink, ref stat);
return(errorCode == 0 ? (int)stat.st_mode : ERROR);
}
private static bool IsSymlink(string path)
{
var buf = new stat_buf();
return
(fstatat(__Ver, AT_FDCWD, path, ref buf, AT_SYMLINK_NOFOLLOW) == 0 &&
(buf.st_mode & (ushort)FilePermissions.S_IFLNK) != 0);
}
private static int StatFile(int fd, string path, bool followSymlink, ref StatBuffer statBuf)
{
// using 'fstatat' instead of the newer 'statx' because Ubuntu 18.04 doesn't have iit
var buf = new stat_buf();
int result = StatFile(fd, path, followSymlink, ref buf);
if (result != 0)
{
return(ERROR);
}
else
{
Translate(buf, ref statBuf);
return(0);
}
}
/// <summary>
/// pathname, dirfd, and flags to identify the target file in one of the following ways:
///
/// An absolute pathname
/// If pathname begins with a slash, then it is an absolute pathname that identifies the target file. In this
/// case, dirfd is ignored.
///
/// A relative pathname
/// If pathname is a string that begins with a character other than a slash and dirfd is AT_FDCWD, then
/// pathname is a relative pathname that is interpreted relative to the process's current working directory.
///
/// A directory-relative pathname
/// If pathname is a string that begins with a character other than a slash and dirfd is a file descriptor
/// that refers to a directory, then pathname is a relative pathname that is interpreted relative to the
/// directory referred to by dirfd.
/// </summary>
private static int StatFile(int dirfd, string pathname, bool followSymlink, ref stat_buf buf)
{
Contract.Requires(pathname != null);
int flags = 0
| (!followSymlink ? AT_SYMLINK_NOFOLLOW : 0)
| (string.IsNullOrEmpty(pathname) ? AT_EMPTY_PATH : 0);
int result;
while (
(result = fstatat(__Ver, dirfd, pathname, ref buf, flags)) < 0 &&
Marshal.GetLastWin32Error() == (int)Errno.EINTR)
{
;
}
return(result);
}
