On Wed, Feb 2, 2022, 21:59 Chet Ramey <chet.ra...@case.edu> wrote: > On 2/2/22 1:40 PM, Martijn Dekker wrote: > > Op 01-02-22 om 15:23 schreef Chet Ramey: > >> Historically, bash (and ksh93) has favored the former. Just about all > the > >> other shells claiming some sort of POSIX conformance favor the latter > (all > >> the ash-based shells, yash, mksh). > >> > >> What are your plans here? > > > > I've no current plans. Any remotely plausible use of aliases is not going > > to be affected either way. I've done some pretty innovative stuff in > > modernish that involves aliases and that too would be unaffected. In my > > view, this difference is relevant to standards and regression test > writers > > and probably no one else. > > I agree; most current scripts will continue to run just fine. > > > Having said that, I've never understood why ksh stores command > > substitutions as unparsed source code (including comments and all) in the > > parse tree and only parses that at execution time -- including in dot > > scripts (which are otherwise parsed in their entirety before execution) > and > > shcomp bytecode output. That seems bizarre. It doesn't do that for > regular > > subshells in parentheses or for process substitutions. > > Probably because the paren commands are never parts of words and it makes > no sense to join a process substitution to another word. > > But command substitutions are parts of words (granted, most of the time the > complete word) so it's simpler to retain the text, parse it again to find > the closing `)' during expansion, and perform the command substitution > than to carry around an arbitrary number of parse trees along with the > word, including where each should start and end. It's probably more > bookkeeping than Korn wanted to do, though Ken Almquist managed it. >
you just need two parts an expander, i guess a language parser and the alias expansion is like text expansion second part is again language interpret but then execute > > Chet > > -- > ``The lyf so short, the craft so long to lerne.'' - Chaucer > ``Ars longa, vita brevis'' - Hippocrates > Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/ > >
