Re: [go-nuts] hook into os.Stdout / os.Stderr

['Axel Wagner' via golang-nuts]

As os.Stdout/os.Stderr are *os.File, not io.Writer, you need to go a step
further and use os.Pipe . Something like
this:
https://play.golang.org/p/V6ygCmwlsiz
TBH, it's not great to do this. As you can tell from the code, this is
pretty complicated and if you want error handling, it gets even more
complex. Then there is the problem that writes are not synchronous, which
can't really be solved, as you write to an `os.File` (going to the OS
directly, so this can't be changed) which can do internal buffering, so the
write can return before your spawned goroutine even sees it.

Really, it is better to pass a custom `io.Writer` or something to whatever
produces the output you want to modify.

On Sat, Sep 19, 2020 at 9:59 PM Raffaele Sena  wrote:

> You can create your own writer and overwrite os.Stdout/Stderr (just supply
> your own write method with the appropriate before/after hooks)
>
> Sent from my iPhone
>
> On Sep 19, 2020, at 12:38 PM, Alexander Mills 
> wrote:
>
> Forgive me for this pigeon code, I am looking to do something like:
>
> os.Stdout.BeforeWrite(func (){
>
> });
>
> os.Stderr.AfterWrite(func(){
>
> })
>
> so I can hook into the system and clear the terminal before hand, and
> write a status line, after wards. Is this possible?
>
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> .
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> .
>

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Re: [go-nuts] hook into os.Stdout / os.Stderr

[Raffaele Sena]

You can create your own writer and overwrite os.Stdout/Stderr (just supply your 
own write method with the appropriate before/after hooks)

Sent from my iPhone

> On Sep 19, 2020, at 12:38 PM, Alexander Mills  
> wrote:
> 
> Forgive me for this pigeon code, I am looking to do something like:
> 
> os.Stdout.BeforeWrite(func (){
> 
> });
> 
> os.Stderr.AfterWrite(func(){
> 
> })
> 
> so I can hook into the system and clear the terminal before hand, and write a 
> status line, after wards. Is this possible?
> -- 
> You received this message because you are subscribed to the Google Groups 
> "golang-nuts" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to golang-nuts+unsubscr...@googlegroups.com.
> To view this discussion on the web visit 
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[go-nuts] hook into os.Stdout / os.Stderr

[Alexander Mills]

Forgive me for this pigeon code, I am looking to do something like:

os.Stdout.BeforeWrite(func (){

});

os.Stderr.AfterWrite(func(){

})

so I can hook into the system and clear the terminal before hand, and write 
a status line, after wards. Is this possible?

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