How to get output of piped process?

[Jesse Phillips]

On Saturday, 6 March 2021 at 21:20:30 UTC, kdevel wrote:
>
> ```pipechain.d
> import std.stdio;
> import std.process;
> import std.conv;
> import std.array;
> import std.range;
> import std.algorithm;
>
> int main (string [] args)
> {
>    auto p = pipe ();
>    auto proc1 = spawnProcess (["cat"], stdin, p.writeEnd);
>    auto q = pipe ();
>    auto proc2 = spawnProcess (["cat"], p.readEnd, q.writeEnd);
>    auto os = appender!string;
>    q.readEnd.byChunk (4096).copy (os);
>    auto res2 = wait (proc2);
>    auto res1 = wait (proc1);
>    stderr.writeln ("res1 = ", res1, ", res2 = ", res2);
>    write (os[]);
>    stderr.writeln ("fin");
>    return 0;
> }
> ```
>
> AFAICS this is immune to SIGPIPE. Do I miss anything?

I probably missed that from the documentation and was trying to 
make it work with pipeProcess.