Re: implementation of <() (creating a temp fifo) ?

[Timothee Cour <timothee.cour2@xxxxxxxxx>]

thanks!

On Sun, Feb 12, 2017 at 10:17 AM, Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>
wrote:

> On Feb 12,  4:32am, Timothee Cour wrote:
> }
> } Could someone kindly point me source code showing how zsh implements <()
> } (temporary named pipe creation)? (ideally a url)
> }
> } * my workaround is to use tempnam but docs says it's not recommended (
> } http://man7.org/linux/man-pages/man3/tempnam.3.html)
>
> There doesn't seem to be any better option for a temporary named pipe.
> mkfifo is relatively safe because there's no way to cause it to re-use
> an existing fifo, so as long as you're confident that the directory
> where the fifo is placed cannot itself be spoofed, using tempnam is OK.
>
> Note that the default build mode for zsh is to instead use /dev/fd/ or
> the equivalent to get a handle to the stdin or stdout of the process,
> and not use a named pipe at all.
>
> Also since any process can connect to a named pipe once it exists, be
> sure you're passing appropriately restrictive file modes to mkfifo.
>
> To answer your direct question:
>
> https://sourceforge.net/p/zsh/code/ci/master/tree/Src/exec.c
>    search for "namedpipe"
>
> https://sourceforge.net/p/zsh/code/ci/master/tree/Src/utils.c
>    search for "gettempname"
>