pipes on steroids

I though I had blogged about that before, but I can't find it anywhere, so I'm just gonna put it here (again?).

Pipes are great. You know that, I know that, everyone knows that. Because/But they are restricted to linear, non conditional flow.

Sometimes, I'd like to have an out-of-band pipe that bypasses a command in the middle, and there's no clear way how to do it.

So here are a few links on how to use file descriptors for advanced use cases. You can use them for this, and for other smart stuff in shells.

• https://catonmat.net/bash-one-liners-explained-part-three
• https://wiki.bash-hackers.org/howto/redirection_tutorial
• http://tldp.org/LDP/abs/html/ioredirintro.html
• http://catern.com/posts/pipes.html
• https://mosermichael.github.io/jq-illustrated/dir/content.html
• https://news.ycombinator.com/item?id=21700014 ( https://www2.dmst.aueb.gr/dds/sw/dgsh/ )
• http://dongyuxuan.me/posts/pipeline.html 
• https://stackoverflow.com/questions/2990414/echo-that-outputs-to-stderr
• http://www.tldp.org/LDP/abs/html/io-redirection.html
• http://wiki.bash-hackers.org/howto/redirection_tutorial 
• https://news.ycombinator.com/item?id=22704774