+AC_CACHE_CHECK([for GNU sed],[rjk_cv_gnused],[
+ rjk_cv_gnused="not found"
+ for candidate in sed gsed; do
+ if $candidate --version >/dev/null 2>&1; then
+ rjk_cv_gnused=$candidate
+ fi
+ done
+])
+GNUSED="${GNUSED:-$rjk_cv_gnused}"
+if test "$GNUSED" = "not found"; then
+ AC_MSG_ERROR([GNU sed is required to build this program])
+fi
+AC_SUBST([GNUSED])
+