On 1/4/24 8:36 AM, Oğuz wrote:
These bugs affect the development branch only.1. `wait -n' doesn't work inside nofork command substitution. I think it should, or wait without `-n' shouldn't work either, or what works and what doesn't should be documented.
Nofork command substitution freezes the jobs list, because you don't want jobs appearing and disappearing in the list while you're running word expansion. If the jobs list is frozen, wait -n doesn't even try waiting, since you don't want jobs removed from the list in, say, a SIGCHLD trap. I think it's ok to do the wait but not delete the job, regardless of what posix says, so I'll make that change for funsubs.
$ sleep 3 & sleep 1; echo ${| wait -n -p REPLY;}
[1] 433
$
[1]+ Done sleep 3
$
2. Sending a signal other than SIGTERM to an asynchronous process
created inside nofork command substitution kills the parent shell.
This should not happen.
Everything in a command substitution is in the same process group as the parent shell, since word expansions are performed by the parent shell and command substitution is a synchronous operation. As a result, asynchronous processes in nofork command substitutions aren't run in a separate process group when job control is active. If you send a signal to the process group, the shell gets it, too. I'm not sure of the right approach here; I'll have to think about it.
There are other cases where the parent shell exits unexpectedly, such as when the exec command fails inside nofork command substitution, but I'm not sure if those are bugs or intended behavior.
Why would that be unexpected, since you're explicitly running something in the calling shell's context, with the expected side effects to that environment?
3. Linking REPLY to a variable inside nofork command substitution renders the target variable unset. I don't think this should be the case; and if it has to, it should be documented.
I agree; I don't think the implicit creation of REPLY as a local variable
should follow namerefs here.
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/
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