Re: nofork command substitution

[Chet Ramey]

On 5/25/23 8:13 AM, Robert Elz wrote:

> Note that ${C } is not a group - it is syntax that delimits a command
> substituition in a word, and what's in a command substitution is a list
> (which can contain groups, or be one, but isn't required to be).

There's not any real difference. A group command is

'{' compound_list '}',

a nofork command substitution is

'${' compound_list '}',

and a command substitution is

'$(' compound_list ')'.

(Similar to how a subshell command is

'(' compound_list ')' ).

This is consistent with the POSIX grammar. The difference, as you say, is
that a command substitution is allowed as part of a word, so the closing
brace isn't a reserved word according to the strict definition.

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/