Allow to read from gwsocket’s stdin with (unnamed) pipe

[jirutka]

It’d be great to be able to do simply tail -f /var/log/nginx/access.log | gwsocket.

Currently it’s possible to read user input from stdin and/or write to stdout using gwsocket --pipein=/dev/stdin --pipeout=/dev/stdout, but this doesn’t work with |.

[allinurl]

I'll look into this, shouldn't be too bad adding stdin to the fd set. Thanks for pointing this out!