lynx-dev "configure" advice needed

[pg]

Hello, Lyncei,

As I work on my patch for Lynx on a non-ASCII system, I
have put the following in config.hin:

    + #undef  NOT_ASCII
    + #if '0'!=48   /* S/390 -- gil -- 1404 */
    + #define NOT_ASCII 1
    + #if '0'==240
    + #undef  EBCDIC
    + #define EBCDIC 1
    + #else
    + #error "Unknown character set"
    + #endif
    + #endif

I now realize this is poorly done; the script that extracts
the configuration definitions is not sensitive to the
compile-time conditionals.  But the C compiler makes these
tests easily, and I know of no simple way to make the same test
in a shell script.  Can anyone suggest a clever way to do
this test at "configure" time?  Should I add a C program
to the suite to emit the lines?

Thanks,
gil