begin-end command grouping isn't discoverable/documented prominently enough

[ulidtko]

Hi!

One thing with fish that I've stumbled over multiple times across years of usage, are situations of this kind: when I have a pipe, and need to inject another command into just one end of the pipe. Nigh realistic example:

🐟 printf 'GET / HTTP/1.1\nHost: example.net\n\n' | openssl s_client -connect example.net:443 -crlf -servername example.net -quiet

With this example, I need to test the server request timeout.
So my bash muscle does this before I even think:

🐟 { sleep 0.1; printf 'GET / HTTP/1.1\nHost: example.net\n\n' } | openssl s_client -connect example.net:443 -crlf -servername example.net -quiet

... which of course fails with fish: Illegal command name “{”.

---

It's not my aim to discuss syntax here; I was able to somehow discover the proper way to say it in fish:

🐟 begin echo ccc; echo zzz; echo aaa; end | sort
aaa
ccc
zzz

🐟 begin sleep 0.1; printf 'GET / HTTP/1.1\nHost: example.net\n\n'; end | openssl s_client -connect example.net:443 -crlf -servername example.net -quiet

What I want to raise issue with — it's too easy to forget and too hard to rediscover. The quick syntax guide, upon skimming, doesn't give answers. begin; end is demonstrated just once, in an example for something different; not easy to spot when you "don't know what you're looking for".

Better yet. Can fish suggest begin; end in the error message for Illegal command name “{”?
Just like it does in Unsupported use of '&&'. In fish, please use 'COMMAND; and COMMAND'.

I think I can roll an easy patch for this — if it sounds good, and the community approves. RFC!

[krobelus]

Better yet. Can fish suggest begin; end in the error message for Illegal command name “{”?
Just like it does in Unsupported use of '&&'. In fish, please use 'COMMAND; and COMMAND'.

A helpful error message would definitely be a great change. It might not
be straightforward because of brace expansion but maybe there's a
simple way to do it.

Btw fish 3 does support && and || :)

Supporting brace grouping natively could be a possibility for the future.
Or ship abbreviations like abbr { begin, but that doesn't work as of now.