Thanks for the bug-fixing and pointing out my misunderstanding of builtin.
I find that conditional expressions like ``[[ 3+3 ]]'' sometimes triger the bug, though I cannot repeat it. I hope it also get fixed in the previous version. At 2023-02-23 23:23:11, "Chet Ramey" <chet.ra...@case.edu> wrote: >On 2/23/23 3:26 AM, Qingsheng Huang wrote: >> Here shows the behavious of empty conditional expressions: >> >> ------------------------------------------------------------------------ >> infinite:~# [[ ]] >> -bash: syntax error near unexpected token `]]' >> infinite:~# [[ ]] >> infinite:~# [[ "$A" ]] >> -bash: syntax error near unexpected token `"$A"' > >This is a bug having to do with resetting the parser state in an >interactive shell after an error token. It was fixed back in October as >the result of > >https://savannah.gnu.org/support/?110745 > >and the fix is in the devel branch. It's ironic that this is the exact >same issue we discussed yesterday in > >https://lists.gnu.org/archive/html/bug-bash/2023-02/msg00150.html > >with a slightly different effect. > > >> According to the manual, I think an empty condition like ``[[ ]]'' and >> ``[[ $EMPTY ]]'' should always triger syntax error, > >No. There has to be at least one operand of [[, but since word expansions >are not performed until [[ executes, a variable expansion is a valid >operand. That's the difference between a compound command and a builtin. > > >-- >``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/
