Re: [BUG] RETURN trap with -o functrace: infinite recursion on 'eval return'
On 4/10/18 5:56 AM, Martijn Dekker wrote:
> $ bash -o functrace -c 'fn() { eval "return"; }; trap "fn" RETURN; fn'
>
> Result: segfault due to infinite recursion.
Thanks for the report; I'll fix this.
__
>
> Even apart from this bug with 'eval return', the effect of '-o functrace'
> is a bit strange:
>
> $ bash -o functrace -c 'fn() { printf foo; fn2; };
> fn2() { printf bar; fn3; };
> fn3() { printf baz\\n; };
> trap fn RETURN; fn'
> foobarbaz
> foobarbaz
> foobarbaz
> foobarbaz
>
> (I'd expect one 'foobarbaz', not four)
>
> It seems odd that the RETURN trap would be triggered while a RETURN trap
> action is still being executed. Might it be better to temporarily
> deactivate the effect of '-o functrace' while a RETURN trap action is being
> executed?
Well, trap handlers are recursive, in the sense that you can execute a trap
on signal X from a signal X trap handler. If the RETURN trap is inherited
by functions, and traps are recursive, wouldn't the bash behavior be the
logical thing to do? (Yes, I know there are problems with recursive signal
handler invocations in bash-4.4.)
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/
Re: Character \001 disappears from here document if 'word' is unquoted.
On 4/12/18 12:13 PM, Jorge Alberto Baca Garcia wrote: > Bash Version: 4.4 > Patch Level: 18 > Release Status: release > > Description: > Character \001 disappears from here document if 'word' is unquoted. Thanks for the report. This will be fixed in the next devel branch push. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/
Re: Errors in documentation
On 4/12/18 6:07 PM, Jorge Maldonado Ventura wrote: >> The SVR4.2 shell has two privilege-related builtins (|mldmode| and > |priv|) not present in Bash. > > This text is under the section "Appendix B Major Differences From The > Bourne Shell"; it should be under the section "B.1 Implementation > Differences From The SVR4.2 Shell". No, that's not what that section means. -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/
Re: [BUG] RETURN trap with -o functrace: infinite recursion on 'eval return'
Op 14-04-18 om 03:49 schreef Chet Ramey: On 4/10/18 5:56 AM, Martijn Dekker wrote: It seems odd that the RETURN trap would be triggered while a RETURN trap action is still being executed. Might it be better to temporarily deactivate the effect of '-o functrace' while a RETURN trap action is being executed? Well, trap handlers are recursive, in the sense that you can execute a trap on signal X from a signal X trap handler. I'm not sure how that would happen. Isn't a signal blocked while executing its trap handler? If the RETURN trap is inherited by functions, and traps are recursive, wouldn't the bash behavior be the logical thing to do? I suppose. But if a signal is blocked while executing the respective trap, perhaps it would also be logical to deactivate the RETURN pseudosignal while executing a RETURN trap. It seems like this is already done for the ERR pseudosignal, as "trap false ERR; false" does not cause an infinite loop. - M.
