dnl check if libtcl library links
tcl_link_works=no
LIBTCL=""
AC_CHECK_LIB(tcl, Tcl_Main, tcl_link_works=yes ; LIBTCL="-ltcl")
AC_CHECK_LIB(tcl84, Tcl_Main, tcl_link_works=yes ; LIBTCL="-ltcl84")
AC_CHECK_LIB(tcl8.4, Tcl_Main, tcl_link_works=yes ; LIBTCL="-ltcl8.4")
AC_CHECK_LIB(tcl8.5, Tcl_Main, tcl_link_works=yes ; LIBTCL="-ltcl8.5")
AC_CHECK_LIB(tcl8.6, Tcl_Main, tcl_link_works=yes ; LIBTCL="-ltcl8.6")