Shell Grammar: multiplecomplete_commands

[39555]

This question should live in the separate discussion. I found the good answer for it.

why are there multiple complete_commands inside the program.

[39555]

In older version of the standard there was only one complete_command See: Stackoverflow answer. Hovewer this was changed in https://www.austingroupbugs.net/view.php?id=1055&nbn=4 to allow streaming evaluation.

The separator between complete_commands is an arbitrary number of newlines, so the program:

echo hello
echo word

has 2 complete_commands.
According to Posix spec

complete_commands: complete_commands newline_list complete_command
                 |                                complete_command
                 ;
complete_command : list separator_op
                 | list
                 ;
list             : list separator_op and_or
                 |                   and_or
separator_op     : '&'
                 | ';'