1 ////////////////////////////////////////////////////////////////////////
2 //
3 // Copyright (C) 2016-2021 The Octave Project Developers
4 //
5 // See the file COPYRIGHT.md in the top-level directory of this
6 // distribution or <https://octave.org/copyright/>.
7 //
8 // This file is part of Octave.
9 //
10 // Octave is free software: you can redistribute it and/or modify it
11 // under the terms of the GNU General Public License as published by
12 // the Free Software Foundation, either version 3 of the License, or
13 // (at your option) any later version.
14 //
15 // Octave is distributed in the hope that it will be useful, but
16 // WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 // GNU General Public License for more details.
19 //
20 // You should have received a copy of the GNU General Public License
21 // along with Octave; see the file COPYING. If not, see
22 // <https://www.gnu.org/licenses/>.
23 //
24 ////////////////////////////////////////////////////////////////////////
25
26 // select may be provided by gnulib. We don't include gnulib headers
27 // directly in Octave's C++ source files to avoid problems that may be
28 // caused by the way that gnulib overrides standard library functions.
29
30 // We don't need select directly, we just need to use it to wait for
31 // input on an open file descriptor.
32
33 #if defined (HAVE_CONFIG_H)
34 # include "config.h"
35 #endif
36
37 #include <sys/select.h>
38
39 #include "wait-for-input.h"
40
41 int
octave_wait_for_input(int fid)42 octave_wait_for_input (int fid)
43 {
44 int retval = -1;
45
46 #if defined (HAVE_SELECT)
47 if (fid >= 0)
48 {
49 fd_set set;
50
51 FD_ZERO (&set);
52 FD_SET (fid, &set);
53
54 retval = select (FD_SETSIZE, &set, 0, 0, 0);
55 }
56 #else
57 octave_unused_parameter (fid);
58
59 retval = 1;
60 #endif
61
62 return retval;
63 }
64