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

[James A. Robinson]

On Sat, Aug 31, 2013 at 10:23 AM, James A. Robinson <ji...@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

[James A. Robinson]

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

[Alexander Sychev]

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

--
Best regards,

  santucco

[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

[James A. Robinson]

Thank you both for the explanation!