1# pipe2.m4 serial 2
2dnl Copyright (C) 2009-2020 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_DEFUN([gl_FUNC_PIPE2],
8[
9  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
10
11  dnl Persuade glibc <unistd.h> to declare pipe2().
12  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
13
14  AC_CHECK_FUNCS_ONCE([pipe2])
15  if test $ac_cv_func_pipe2 != yes; then
16    HAVE_PIPE2=0
17  fi
18])
19