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Re: OS_File question

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In article <5cafa1143ebob@sick-of-spam.invalid>,
   Bob Latham <bob@sick-of-spam.invalid> wrote:
> I would like to understand what this means...

> It's from PRM OS_File 13.
> If R0=13
>  R4 = pointer to control-character terminated comma separated path
> string.
> What does that mean? I can find no examples anywhere.

It means what it says! Remember a path ends in a full stop.
I assume that the 'comma separated' is referring to the register
separation, not the components of the path string, which are separated
by full stops (or colon)

> I have no problem with OS_File 17, I've used it for years but 13 I
> just can't work out what I'm doing wrong but work for me it does
> not.

> I read this as R4 points to a path to a directory terminated by
> zero. R1 points to a file name, zero terminated.

Zero terminators would work, but it can be any control character.

> So I expect this to look for the file in that directory but it
> doesn't.
> And what have commas got to do with it?

From that I assume you are writing in BASIC. The commas separate the
register parameters. The single line:

    SYS "OS_File",13,"Desktop",,,"ADFS::SSD.$.!Boot.Choices.Boot." 
        TO r0%,r1%,r2%,r3%,r4%,r5%

reads details for the Desktop file in Boot, setting registers to
something like:

    r0%=1 ~r1%=&4E9FD0 ~r2%=&FFFFEA5B ~r3%=&ECF6D418 
    r4%=5389 r5%=3

The three commas after "Desktop" pass null values in for registers r2
and r3, as they are not used.

-- 
Martin Avison 
Note that unfortunately this email address will become invalid
without notice if (when) any spam is received. 

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Thread

OS_File question Bob Latham <bob@sick-of-spam.invalid> - 2026-02-23 11:40 +0000
  Re: OS_File question Martin <News04@avisoft.f9.co.uk> - 2026-02-23 12:33 +0000
    Re: OS_File question Theo <theom+news@chiark.greenend.org.uk> - 2026-02-23 13:20 +0000
      Re: OS_File question Martin <News04@avisoft.f9.co.uk> - 2026-02-23 14:13 +0000
      Re: OS_File question Bob Latham <bob@sick-of-spam.invalid> - 2026-02-23 14:22 +0000
    Re: OS_File question Bob Latham <bob@sick-of-spam.invalid> - 2026-02-23 14:15 +0000

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