+AC_ARG_WITH([readline],
+ [AS_HELP_STRING([--with-readline],
+ [use GNU readline for line-editing functionality (default: auto)])],
+ [], [with_readline=auto])
+AS_CASE([$with_readline],
+ [no], [gl_cv_lib_readline=no],
+ [yes|auto], [:],
+ [*], [AC_MSG_ERROR([invalid option --with-readline=$with_readline])])
+