[TUHS] Use of "{}" in the Shell?

[Alexis via TUHS]

Dave Horsfall via TUHS <tuhs at tuhs.org> writes:

> A long time ago, in a Unix manpage far away, I saw a reference 
> to "{}"
> which acted similar to "()" except that it did not fork 
> e.g. "{exit}" would
> do just that :-)
>
> Does anyone know the provenance of this Shell?  I can't seem to 
> reproduce
> it on the MacBook or the FreeBSD box here (my Penguin box is 
> currently
> dead).

Well, the dash(1) man page has:

  Grouping Commands Together
    Commands may be grouped by writing either

        (list)

    or

        { list; }

    The first of these executes the commands in a subshell. 
    Builtin commands
    grouped into a (list) will not affect the current shell.  The 
    second form
    does not fork another shell so is slightly more efficient.


Alexis.