struct stat st;
if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0) // exists and is directory
struct stat st;
if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0) // exists and is directory