Re: Bash PS4 and indirection level

[Chet Ramey]

On 11/17/20 9:30 AM, Kevin Shell wrote:
> On Tue, Nov 17, 2020 at 09:12:52AM -0500, Chet Ramey wrote:
> > On 11/17/20 8:12 AM, Kevin Shell wrote:
> > > Hello bash list.
> > >
> > > What constitutes a level of indirection?
> > > The bash manual says the first character of $PS4
> > > indicates one level of indirection but says nothing
> > > about what constitutes an indirection level.
> > >
> > > I found the eval command constitutes one indirection level.
> >
> > Yes, it's essentially a measure of command nesting.
> Is it mean the command will be processed
> by the bash lexer/parser one time per indirection level?

More or less. It's one time through the shell equivalent of the
read-eval-print loop (read-parse-execute-wait?).


--
``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/