1# pipe2.m4 serial 2 2dnl Copyright (C) 2009-2012 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