new file mode 100644
--- /dev/null
+++ b/auto/func
@@ -0,0 +1,21 @@
+
+echo "checking for $NGX_FUNC"
+
+echo "$NGX_UNISTD_H" > autotest.c
+echo "$NGX_FUNC_INC" >> autotest.c
+echo "int main() { $NGX_FUNC_TEST; return 0; }" >> autotest.c
+
+eval "${CC} -o autotest autotest.c > /dev/null 2>&1"
+
+if [ -x autotest ]; then
+    echo " + $NGX_FUNC found"
+
+    echo "#ifndef $NGX_HAVE"      >> $NGX_AUTO_CONFIG_H
+    echo "#define $NGX_HAVE  1"   >> $NGX_AUTO_CONFIG_H
+    echo "#endif"                 >> $NGX_AUTO_CONFIG_H
+    echo                          >> $NGX_AUTO_CONFIG_H
+else
+    echo " + $NGX_FUNC not found"
+fi
+
+rm autotest*