/usr/bin/env is the standard for developer systems where different
configurations are managed through environmental variables. However, it's
rather fragile for non-developers, as it requires properly conditioned
environmental variables.
This statement confuses me greatly. Can you elaborate? I think the only
environment variable which is relevant is PATH, and PATH will certainly
contain /usr/bin. So if PATH contains /usr/bin, and there is a
/usr/bin/ijconsole, then #!/usr/bin/env ijconsole will do the right thing. If
ijconsole is somewhere other than /usr/bin, and it is in PATH, then
#!/usr/bin/env ijconsole will pick it up, but #!/usr/bin/ijconsole will not.
So using /usr/bin/env is strictly less fragile.
Using /usr/bin/env is standard for scripts. /usr/bin/ijconsole entails
_strictly_ more fuss, more fragility, and less portability.
An example: on many BSD systems, bash does not come with the base system, but
is rather provided as a separate package, so it is placed in /usr/local/bin.
Some scripts developed on linux are distributed that use #!/bin/bash, and this
breaks on BSD systems because there is on bash in /bin; when those scripts use
#!/usr/bin/env bash instead, they work.
On Fri, 10 Mar 2023, Raul Miller wrote:
/usr/bin/$name is the earlier standard for minimal fuss distribution.
Given that most J users are going to be in some IDE, I don't see that
the /usr/bin/env approach would provide significant benefit to the J
community. Especially if we're considering people who would be baffled
about what to do with #!/usr/bin/ijconsole
Do you think I've overlooked something important here?
Thanks,
--
Raul
On Fri, Mar 10, 2023 at 7:42 PM Elijah Stone <elro...@elronnd.net> wrote:
Performance is irrelevant here--the difference in either case is miniscule.
Using /usr/bin/env is standard practice in shebangs for finding binaries on
the path. In some systems, it is conventional to put binaries that did not
come with the system in /usr/local/bin, or in /opt; whereas, the existence of
/usr/bin/env is mandated by posix. We should not presume any more than we
need to about the way a user's system will be organised.
On Fri, 10 Mar 2023, Raul Miller wrote:
> Yes, the name ijconsole (iverson j console) was adopted to work around
> java's jconsole being in $PATH on many systems.
>
> This would also be an issue with /usr/bin/env
>
> But I don't see any high priority problems with /usr/bin/ijconsole as
> a standard location. There will be some users who cannot install J
> there, but it should be simple enough for them to build a tool to
> patch incoming J scripts with the install location that they used.
>
> (And, /usr/bin/env is going to be considerably slower than a bit of
> undefined verb parsing and garbage collection within J.)
>
> --
> Raul
>
> On Fri, Mar 10, 2023 at 6:51 PM Elijah Stone <elro...@elronnd.net> wrote:
>>
>> Fair enough. I think the obvious thing is #!/usr/bin/env jconsole. But I
>> gather 'jconsole' is also the name of a java-related program, which might be
>> why debian uses 'ijconsole' (and I think I have seen 'jc' elsewhere--probably
>> for the same reason). I therefore propose:
>>
>> 1. Rename jconsole to something which doesn't collide with anything
heretofore
>> notable
>>
>> 2. Use #!/usr/bin/env that-something
>>
>> On Fri, 10 Mar 2023, Raul Miller wrote:
>>
>> > Perhaps, but I think it would be more useful to have a portable,
>> > agreed on path for systems which support the #! convention.
>> >
>> > That's required for J scripts to be distributable.
>> >
>> > Thanks,
>> >
>> > --
>> > Raul
>> >
>> > On Fri, Mar 10, 2023 at 12:04 AM Elijah Stone <elro...@elronnd.net> wrote:
>> >>
>> >> Perhaps it's simply time to tell the interpreter to start ignoring the
first
>> >> line of a script if it starts with #!...
>> >>
>> >> On Thu, 9 Mar 2023, Raul Miller wrote:
>> >>
>> >> > The recent change in directory naming from j903 to j9.4 introduces an
>> >> > interesting issue for shell scripts on unix-like systems.
>> >> >
>> >> > In J shell scripts, this works:
>> >> >
>> >> > #!/home/username/j903/bin/jconsole
>> >> >
>> >> > However, this fails with a spelling error:
>> >> >
>> >> > #!/home/username/j9.4/bin/jconsole
>> >> >
>> >> > Or, on OSX, the shebang line is different, but the spelling error
remains:
>> >> >
>> >> > #!/Applications/j9.4/bin/jconsole
>> >> >
>> >> > That said, there's some other issues here, related to portability. One
>> >> > of which is that (as a general rule) a home directory is personal
>> >> > rather than portable. Another is that there's official java jconsole
>> >> > which does not understand J.
>> >> >
>> >> > But, also, for a long time now, Debian based distributions have been
>> >> > distributing j with /usr/bin/ijconsole as a symbolic link to the
>> >> > current installed location for J. (Here, the 'i' in ijconsole stands
>> >> > for Iverson.)
>> >> >
>> >> > So I think that now would be a good time to adopt that as "documented
>> >> > standard practice" for j shell scripts.
>> >> >
>> >> > FYI,
>> >> >
>> >> > --
>> >> > Raul
>> >> > ----------------------------------------------------------------------
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