[cs631apue] question about pipeline

[zding4]

Hi everyone,

When we deal with pipeline, like
cmd1 | cmd2 | cmd3

Should our shell wait for all 3 cmd?

please check the commands below
$ sleep 10 | echo hello (this case shell will output hello and will also 
wait for sleep cmd)
$ ls -R / | echo hello (this case shell only output hello, it seems 
shell didn't wait for ls -R / cmd)
So I got a little bit confused.

Sincerely,
Zhizhuo