Pipe | Redirection < > Precedence

Question

I want to make clear when does pipe | or redirection < > takes precedence in a command?

This is my thought but need confirmation this is how it works.

Exa

Answer 1

It's a little unorthodox, but perfectly legal, to place the < anywhere you like, so I prefer this as it better illustrates the left-to-right data flow:

output.txt

The only time you cannot do this is with built-in control structure commands (for, if, while).

# Unfortunately, NOT LEGAL

Note that all of these are equivalent commands, but to avoid confusion you should use only the first or the last one:

Because the file name must always come directly after the redirection operator, I prefer to leave out the optional space between the < and the file name.