[9fans] reading addr always returns #0,#0?

[9fans] reading addr always returns #0,#0?

[James A. Robinson]

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Say I have an acme window with a $winid of 2.
If I type the following commands:

$ echo -n , | 9p write acme/2/addr
$ echo dot=addr | 9p write acme/2/ctl

I see the entire text of the window get selected.
I had assumed that if I then read addr that I would
get back two numbers, 0 and the final byte offset
of the file (it is a non-zero length file).

However, I get back two zeros:

$ 9p read acme/2/addr
          0           0

What am I missing?

Jim

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Re: [9fans] reading addr always returns #0,#0?

[James A. Robinson]

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On Sat, Aug 31, 2013 at 10:23 AM, James A. Robinson <
jimr@highwire.stanford.edu> wrote:

> I see the entire text of the window get selected.
> I had assumed that if I then read addr that I would
> get back two numbers, 0 and the final byte offset
> of the file (it is a non-zero length file).
>
> However, I get back two zeros:
>
> $ 9p read acme/2/addr
>           0           0
>
> What am I missing?
>

I should have said character offset, not byte offset.
I was also experimenting with using addr=dot, but
didn't see any change in behavior.

Jim

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Re: [9fans] reading addr always returns #0,#0?

[Alexander Sychev]

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Hi,
The problem is the "addr" file is closed between your calls. When you open
the "addr" file next time, an internal address is set to 0,0.
But after the writing the address is actual and if you read "data" file you
will see the text according to your address.

I you write the code on C or Go without a closing a descriptor of "addr"
file, everything will be ok :-)
<------------------------------------------------------------------------------------->
santucco@santucco ~/work/go/src/test $ cat test.go
package main

import (
        "bitbucket.org/santucco/goacme"
        "fmt"
        "io"
)

func main() {
        w, err:=goacme.New()
        if err!=nil {
                panic(err)
        }
        defer w.Close()
        if _, err:=w.Write([]byte("test\ntest2\n")); err!=nil {
                panic(err)
        }
        if err:=w.WriteAddr("#5,#10"); err!=nil {
                panic(err)
        }
        f, err:=w.File("addr")
        if err!=nil {
                panic(err)
        }
        b:=make([]byte,100)
        if _, err:=f.Read(b); err!=nil&&err!=io.EOF {
                panic(err)
        }
        fmt.Println(string(b))
}
santucco@santucco ~/work/go/src/test $ go build
santucco@santucco ~/work/go/src/test $ ./test
          5          10

<------------------------------------------------------------------------------------->
Best regards,
  santucco


On Sat, Aug 31, 2013 at 9:29 PM, James A. Robinson <
jimr@highwire.stanford.edu> wrote:

> On Sat, Aug 31, 2013 at 10:23 AM, James A. Robinson <
> jimr@highwire.stanford.edu> wrote:
>
>> I see the entire text of the window get selected.
>> I had assumed that if I then read addr that I would
>> get back two numbers, 0 and the final byte offset
>> of the file (it is a non-zero length file).
>>
>> However, I get back two zeros:
>>
>> $ 9p read acme/2/addr
>>           0           0
>>
>> What am I missing?
>>
>
> I should have said character offset, not byte offset.
> I was also experimenting with using addr=dot, but
> didn't see any change in behavior.
>
> Jim
>
>


--
Best regards,
  santucco

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Re: [9fans] reading addr always returns #0,#0?

[dexen deVries]

On Monday 02 of September 2013 14:13:56 Alexander Sychev wrote:
> The problem is the "addr" file is closed between your calls. When you open
> the "addr" file next time, an internal address is set to 0,0.
> But after the writing the address is actual and if you read "data" file you
> will see the text according to your address.
> 
> I you write the code on C or Go without a closing a descriptor of "addr"
> file, everything will be ok :-)


or use 9p rdwr:


echo -n , | 9p write acme/2/addr
echo 'dot=addr' | 9p rdwr acme/2/ctl 

-- 
dexen deVries

[[[↓][→]]]

Take care of the luxuries and the necessities will take care of themselves.
                -- L. Long

Re: [9fans] reading addr always returns #0,#0?

[James A. Robinson]

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Thank you both for the explanation!


On Mon, Sep 2, 2013 at 3:38 AM, dexen deVries <dexen.devries@gmail.com>wrote:

> On Monday 02 of September 2013 14:13:56 Alexander Sychev wrote:
> > The problem is the "addr" file is closed between your calls. When you
> open
> > the "addr" file next time, an internal address is set to 0,0.
> > But after the writing the address is actual and if you read "data" file
> you
> > will see the text according to your address.
> >
> > I you write the code on C or Go without a closing a descriptor of "addr"
> > file, everything will be ok :-)
>
>
> or use 9p rdwr:
>
>
> echo -n , | 9p write acme/2/addr
> echo 'dot=addr' | 9p rdwr acme/2/ctl
>
> --
> dexen deVries
>
> [[[↓][→]]]
>
> Take care of the luxuries and the necessities will take care of themselves.
>                 -- L. Long
>
>
>

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