What does pipe character do in vim command mode? (for example, :vimgrep /pattern/ file | another_cmd)

Question

What does pipe character do in vim command mode?

For example, :vimgrep /pattern/ file | copen

Does it act like a pipe in Linux Command Line? Contents of vimgrep gets piped to copen?

Or does it separate commands like ; in Command Line?

Answer 1

| is used to execute more than one command at a time.

In your example:

:vimgrep /pattern/ file | copen

This finds for the pattern in the specified file and then opens a window to show current list of occurrence of pattern.

The second command (and subsequent commands) are only executed if the prior command succeeds.