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Groups > alt.sys.pdp10 > #9970
| From | Rich Alderson <news@alderson.users.panix.com> |
|---|---|
| Newsgroups | alt.sys.pdp10 |
| Subject | Re: Command line parsing and MACRO-20 |
| Date | 2026-08-29 17:51 -0400 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <mdd7bl8fvdy.fsf@panix5.panix.com> (permalink) |
| References | <87fqzyjexe.fsf@atr2.ath.cx> <aykkS.2694$aIQa.1285@fx18.iad> <87h5kchpbs.fsf@atr2.ath.cx> |
jayjwa <jayjwa@atr2.ath.cx.invalid> writes:
> erjmp [hrroi t1, [asciz /Error on .RSINI. Exiting./]
> psout%
> haltf%] ; Halt on rscan/rsini error
Every one of your ERJMP routines ends incorrectly.
HALTF% does not prevent the EXEC from continuing the program, which it will do
from the instruction following the HALTF%.
"But wait!" you say, "there's no following instruction!"
Oh, yes, there is. You just have no idea what it might be.
Literals are packed together in the space following the main program text, or
following a LIT pseudo-op if you use one. Since your ERJMPs all type out error
messages, a continue after one will type the next error message in order
through your program.
The correct idiom, and I know it's present in Ralph's book, is to put a
JRST .-1
after each HALTF%, so that a CONTINUE command forces the return to the EXEC.
NB: A JRST .-3 would repeat the "correct" error message and then stop.
--
Rich Alderson news@alderson.users.panix.com
Audendum est, et veritas investiganda; quam etiamsi non assequamur,
omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen
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Command line parsing and MACRO-20 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-08-28 14:08 -0400
Re: Command line parsing and MACRO-20 scott@slp53.sl.home (Scott Lurndal) - 2026-08-28 18:35 +0000
Re: Command line parsing and MACRO-20 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-08-29 12:19 -0400
Re: Command line parsing and MACRO-20 Rich Alderson <news@alderson.users.panix.com> - 2026-08-29 17:51 -0400
Re: Command line parsing and MACRO-20 Rich Alderson <news@alderson.users.panix.com> - 2026-08-28 20:59 -0400
Re: Command line parsing and MACRO-20 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-08-29 12:37 -0400
Re: Command line parsing and MACRO-20 Rich Alderson <news@alderson.users.panix.com> - 2026-08-29 18:04 -0400
Re: Command line parsing and MACRO-20 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-08-30 11:38 -0400
Re: Command line parsing and MACRO-20 Rich Alderson <news@alderson.users.panix.com> - 2026-08-30 22:18 -0400
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