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Re: Input line editing

Thor Lancelot Simon wrote:
On Thu, Feb 12, 2009 at 11:51:58AM +0100, Johnny Billquist wrote:
Finally someone said it. :-)

But the COMND% JSYS wasn't exactly just line editing. I could just wish for COMND%, but that's not likely to happen. COMND% was more about describing the structure of the line expected, so that completion could be done on it. (TOPS-20 can to completion on everything, not just filenames.)

If you want this on Unix, the 'ccmd' library from Columbia MM is probably
the easiest way to get it.

There are, though, three basic problems with ccmd:

1) It's more or less a translation from PDP-10 assembly into C.  Not so
   easy to maintain.

2) It's very large, despite #1.

3) It uses 8th-bit-stealing to encode state as it parses.  So it will
   never be able to deal with alternate character sets without a major,
   almost total, rewrite.

True. And it also isn't really system global, but yet another library that you must link into your specific program. But that's partly a result from the design philosophy of Unix. Keep as little as possible in the kernel, and let each program deal with things by itself, in the fashion that it sees fit. It has its pros and cons.

Do anyone even maintain ccmd these days?


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email:             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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