Parsing command-line arguments for module commands
Terje Slettebø
module, the command entry point receives the command tail, and the
number of arguments there is, but the arguments are not separated in
any way.
Is there a way using RISC OS to split the tail up, to get e.g. an
array of arguments, in a way that takes into account quoted strings
(like RISC OS apparently does when it counts the arguments)?
Regards,
Terje
Martin Bazley
SWI "OS_ReadArgs".
Good luck wrangling with the explanation of the syntax string format,
though; it took me hours of experimentation to determine exactly what
each letter code did, and what they did when combined. Let me know if
you need help and I'll see if I can dig out my old notes.
--
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Terje Slettebø
wrote:
> SWI "OS_ReadArgs".
>
> Good luck wrangling with the explanation of the syntax string format,
> though; it took me hours of experimentation to determine exactly what
> each letter code did, and what they did when combined. Let me know if
> you need help and I'll see if I can dig out my old notes.
Hi Martin.
Thanks. I did look at OS_ReadArgs, but it seemed to only support
parameters of the type "-<name>[ <value>]", so you couldn't use it
e.g. to parse the parameters of a command like "*copy <from> <to>".
In any case, I found that in my case, I'll manage with a simple way of
doing this, since it doesn't need to handle quoted strings.
Regards,
Terje
Martin Bazley
> On Sep 11, 1:13 am, Martin Bazley <martin.baz...@blueyonder.co.uk>
> wrote:
>
> > SWI "OS_ReadArgs".
> >
> parameters of the type "-<name>[ <value>]", so you couldn't use it
> e.g. to parse the parameters of a command like "*copy <from> <to>".
string is entirely optional - all you need are the commas separating
each argument, and /A inserted between them if a parameter is
compulsory.
As the StrongHelp manual puts it, "," is a perfectly valid syntax
string. Presumably the null string is also. The last time I used this,
I was writing a utility to save memory starting from a certain address
to a file (determining the length of memory to save from the contents of
the address given being the purpose of the utility). I used the string
"/A,/A/E".
One thing you do have to watch out for is that OS_ReadArgs generates a
rather unhelpful error if the parameters are junk, so standard practice
is to call it with the X flag set and, if V set, print a message of your
own along the lines of, "Syntax: <program> [-<arg1>] -<arg2>".
Terje Slettebø
wrote:
>
> > On Sep 11, 1:13 am, Martin Bazley <martin.baz...@blueyonder.co.uk>
> > wrote:
>
> > > SWI "OS_ReadArgs".
>
> > Thanks. I did look at OS_ReadArgs, but it seemed to only support
> > parameters of the type "-<name>[ <value>]", so you couldn't use it
> > e.g. to parse the parameters of a command like "*copy <from> <to>".
>
> Yes, you can. I do it all the time. The <name> part in the syntax
> string is entirely optional - all you need are the commas separating
> each argument, and /A inserted between them if a parameter is
> compulsory.
>
> As the StrongHelp manual puts it, "," is a perfectly valid syntax
> string. Presumably the null string is also. The last time I used this,
> I was writing a utility to save memory starting from a certain address
> to a file (determining the length of memory to save from the contents of
> the address given being the purpose of the utility). I used the string
> "/A,/A/E".
>
> One thing you do have to watch out for is that OS_ReadArgs generates a
> rather unhelpful error if the parameters are junk, so standard practice
> is to call it with the X flag set and, if V set, print a message of your
> own along the lines of, "Syntax: <program> [-<arg1>] -<arg2>".
Regards,
Terje