+AC_CHECK_LIB(iconv, iconv_open, ICONV_LIBS="-liconv")
+AC_CHECK_LIB(iconv, libiconv_open, ICONV_LIBS="-liconv")
+AC_SUBST(ICONV_LIBS)
+LIBS="$LIBS $ICONV_LIBS"
+AC_SEARCH_LIBS(sqrtf, m)
+
+# nanosleep may not be part of libc, also search it in other libraries
+AC_SEARCH_LIBS(nanosleep, rt)
+
+AC_SEARCH_LIBS(dlopen, dl)