4.3.4 Simple command
A simple command is a sequence of
variable assignments (optional)
command name
arguments (optional)
redirections (optional: > , >> ,
< , << , etc.)
control operator (optional: && , || ;
<newline> , ; , & , ( ,
) )
For more complex commands with quotations and substitutions, see Command-line processing, Section
13.2.6.
