Spawning a pty in D

[Colin Grogan]

On Thursday, 17 October 2013 at 14:12:36 UTC, Adam D. Ruppe wrote:
> On Thursday, 17 October 2013 at 13:53:39 UTC, Colin Grogan 
> wrote:
>> Anyone have any experience with this?
>
> I actually have been writing a terminal emulator for the last 
> few weeks
> https://github.com/adamdruppe/terminal-emulator
>
> But for reading and writing from the pty, I just used the unix 
> read and write syscalls instead of wrapping it. tbh I don't 
> think there's much point in wrapping it; I think std.stdio.File 
> is hard to use for any byte-at-a-time tasks anyway...
>
> If you do want to wrap it... well I think you'd have to modify 
> phobos. The constructor that takes a FILE* is private. 
> (std.stdio is itself just a wrapper around C's <stdio.h>)
>
>
> But I wouldn't even bother, it is easiest to just use "import 
> core.sys.posix.unistd;" and then read()/write() to it.
>
>> As an aside, I'd prefer to do this in a pure D way, and not 
>> have to compile against any external C libraries, does anyone 
>> know if it is possible to spawn a pty in D without resorting 
>> to calling external C libs?
>
> eh you could probably open /dev/ptmx and the other /dev/pts/* 
> to test and reimplement what openpty does yourself, but there 
> really is no pure D way, because it is perfectly normal in D to 
> use C interfaces to talk to the operating system (it IS 
> possible to use D without a C lib, but even druntime assumes it 
> is there). I've never seen a unix install without the terminal 
> util lib, so it is basically part of the OS.

Thanks for that Adam, was a great help to me.

I studied your code quite a bit (and reused some of it if that's 
ok?!). I stuck an initial draft of dexpect up on github, located:
     https://github.com/grogancolin/dexpect
if you want to see the fruits of your labor :)

Theres still some bugs I need to iron out, but I threw it up 
there to keep safe nonetheless.

I ended up going with what you said and didnt wrap any of the C 
functions, turns out using them is kind of satisfying and pretty 
easy anyway. Just need to read up on documentation a bit more is 
all!

Cheers,
Colin