> On Jun 1, 2023, at 6:18 PM, Joshua Root <j...@macports.org> wrote:
>
> Ken Cunningham wrote:
>
>> what you see is difficult to explain, unless the PATH changed between the
>> two tests.
>>
>> if
>>
>> 'which gcc' gives /opt/local/bin/gcc
>>
>> then
>>
>> gcc --version
>>
>> should give exactly the same as
>>
>> /opt/local/bin/gcc --version
>
> Not necessarily. Shells cache command locations, so if 'gcc' was run prior to
> the creation of /opt/local/bin/gcc, subsequently invocations will continue to
> run the previously found gcc. Running 'hash -r' or starting a new shell will
> give you an empty cache and thus set things right.
>
> The 'which' command doesn't know about the shell's cache state; it only looks
> at the current PATH. This is why 'type' often helps to understand what's
> going on in these situations, as Richard hinted.
>
> - Josh
>
You have probably already noted that which and type are both built in to the
default zsh on Ventura and as far as I can tell from my testing here give
identical results in every case. Both correctly predict the binary that will be
executed in every case I tried.
What will happen when you add and remove binaries from an upstream PATH folder
is a bit difficult to predict accurately. I won't try to summarize the findings
only to have someone point out their idea of an exception, but it's fair to say
that it's best to open a new shell to get predictable results.
K
