Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.sys.acorn.programmer > #5485
| Path | csiph.com!feeder.erje.net!2.eu.feeder.erje.net!ecngs!feeder2.ecngs.de!proxad.net!feeder1-1.proxad.net!cleanfeed2-b.proxad.net!nnrp3-2.free.fr!not-for-mail |
|---|---|
| From | "John Williams (News)" <UCEbin@tiscali.co.uk> |
| Subject | Re: Testing from a BASIC program the existence of a module |
| Newsgroups | comp.sys.acorn.programmer |
| Date | Fri, 20 Jul 2018 17:48:00 +0100 |
| Message-ID | <571aa88b3dUCEbin@tiscali.co.uk> (permalink) |
| References | <2c617d2a-d8ae-45e3-b90b-4845c5eb243a@googlegroups.com> |
| User-Agent | Pluto/3.16 (RISC OS/5.25) NewsHound/v1.52-32 |
| Organization | League of Underpaid, Overworked, Undervalued, and Overwhelmed |
| X-Disclaimer | I reserve the right to be wrong! |
| Reply-To | UCEbin@tiscali.co.uk |
| Lines | 46 |
| NNTP-Posting-Date | 20 Jul 2018 18:48:06 CEST |
| NNTP-Posting-Host | 81.155.66.107 |
| X-Trace | 1532105286 news-2.free.fr 5487 81.155.66.107:50739 |
| X-Complaints-To | abuse@proxad.net |
| Xref | csiph.com comp.sys.acorn.programmer:5485 |
Show key headers only | View raw
In article <2c617d2a-d8ae-45e3-b90b-4845c5eb243a@googlegroups.com>, Xavier Louis Tardy <xltardy@gmail.com> wrote: > As the title says, how can I test, from BASIC, the existence of a module ? > I'd like a real test for existence please, not a call and handling an > error returned if the module is not present. Thanks in advance. Normally one would use the OS command RMEnsure in a Run file to check for the presence of a module and this allows a command to be executed if it's not present. Normally this would be a command to RMLoad the module. But it could be anything. It could be to raise an error, but it could be something else You obviously have some reason for doing this from within a BASIC program, whether multi or single-tasking. I think if I had this problem I would call an Obeyfile from within the BASIC and get it to set a system variable depending on the result. When this OSCLI command returned to BASIC I would interrogate the system variable using a routine such as this: : DEF FN_readsysvariable(sysvar$) SYS"OS_ReadVarVal",sysvar$,block%,255,0,3 TO ,,val% block%?val%=13 val$=$block% =val$ : Note that this requires a variable block% to have been dimensioned to size 255. You then treat the returned string as a flag and do whatever you wish with it. This avoids the error scenario as you wish. John -- John Williams, now back in the UK - no attachments to these addresses! Non-RISC OS posters change user to johnrwilliams or put 'risc' in subject! Who is John Williams? http://petit.four.free.fr/picindex/author/
Back to comp.sys.acorn.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Testing from a BASIC program the existence of a module xltardy@gmail.com - 2018-07-20 01:40 -0700
Re: Testing from a BASIC program the existence of a module Vince M Hudd <atdotcodotuk@dotcodotukat.co.uk> - 2018-07-20 11:08 +0100
Re: Testing from a BASIC program the existence of a module "John Williams (News)" <UCEbin@tiscali.co.uk> - 2018-07-20 17:48 +0100
Re: Testing from a BASIC program the existence of a module Vince M Hudd <atdotcodotuk@dotcodotukat.co.uk> - 2018-07-20 18:58 +0100
Re: Testing from a BASIC program the existence of a module "John Williams (News)" <UCEbin@tiscali.co.uk> - 2018-07-20 19:47 +0100
Re: Testing from a BASIC program the existence of a module Steve Fryatt <news@stevefryatt.org.uk> - 2018-07-20 20:01 +0100
Re: Testing from a BASIC program the existence of a module lydia.harston2@gmail.com - 2018-07-21 08:53 -0700
Re: Testing from a BASIC program the existence of a module Vince M Hudd <atdotcodotuk@dotcodotukat.co.uk> - 2018-07-21 22:28 +0100
Re: Testing from a BASIC program the existence of a module lydia.harston2@gmail.com - 2018-07-22 04:01 -0700
csiph-web