Re: When a hashed pathname is deleted, search PATH

[Linda Walsh]

Chet Ramey wrote:
> Because the execution fails in a child process.  You'd be able to fix it
> for that process, but would do nothing about the contents of the parent
> shell's hash table.
>
> The way the option works now is to check the hash lookups and delete
> anything that is no longer an executable file, then redo the lookup and
> hash the new value.
----
Wouldn't bash notice that the child exited in <.1 seconds (
or is it less?

I.e. if bash spawns a child for an exec and gets a sigchild
from it < (some small value of time) later, THEN it could
check the path that was just executed ???

That would keep any side performance hits to a rather small
number of cases with relatively few false positives.

The up side is the delay in the parent would only happen
AFTER a command has been attempted, and immediately failed.
I think a further lookup in the parent should happen in
< 1ms given that the path lookup just happened in the
child and most OS's would have cached the path lookup
when the child did it.  I.e. -  the parent would have next to
zero delay in rewalking a "hot" path.