Re: utils/perldoc.Com vs utils/perldoc

On Sep 21, 2013, at 1:33 PM, "John E. Malmberg" =
<[email protected]> wrote:
>=20
> The wrapper that simulates the shebang only runs it in a way that =
produces an error message.  I can not find any way to run it that takes =
advantage of the wrapper and results in useful output.
>=20
> All attempts to run perldoc.com as a command instead of as a perl =
script that I can find just result in it emitting an error message.


OK.  I think I see where we are talking at cross purposes.  I was =
talking exclusively about how the shebang emulation works in the general =
case by having $Config{startperl} prepended to the .com file.  I assumed =
that perldoc.com would work just the same as any other comparable =
utility in this respect, but it doesn't.  Bad assumption on my part.  =
Sorry about that.

I think you might have been assuming the same thing in reverse, namely =
that if perldoc.com has a problem, there must be a more general problem =
with the shebang emulation.  But I don't think there is.

The following illustrations that the shebang emulation works just fine =
in the general case:

$ type testshebang.com
$ perl 'f$env("procedure")' "''p1'" "''p2'" "''p3'" "''p4'" "''p5'" =
"''p6'" "''p7'" "''p8'"!
$ exit++ + ++$status!=3D0 and $exit=3D$status=3Dundef; while($#ARGV !=3D =
-1 and $ARGV[$#ARGV] eq ''){pop @ARGV;}
    eval 'exec perl_root:[000000]Perl.exe -S $0 ${1+"$@"}'
	if 0;

require 5;
print "hello\n";
$ define DCL$PATH SYS$DISK:[]
%DCL-I-SUPERSEDE, previous value of DCL$PATH has been superseded
$ testshebang
hello

But perldoc.com doesn't work that way, as you discovered, and it's =
because it's a pretty thin wrapper around Pod::Perldoc::run.  So there =
is a bug in Pod::Perldoc (specifically Pod::Perldoc::program_name) which =
makes invalid and non-portable assumptions about the name of the file =
it's running.  As far as I can see from a quick look, the only real =
problem is that it doesn't know what to do with the version number, =
i.e., "perldoc.com;1" is unacceptable, whereas "perldoc.com" would be =
ok.

I have no time for (and not much interest in) pursuing this further, but =
most likely replacing the line in Perldoc.pm that looks like:

    (?: \. (?: bat | exe | com ) )?    # possible extension

with

    (?: \. (?: bat | exe | com | com;\d+ ) )?    # possible extension

would do the trick.  And version numbers on .exe files are also possible =
of course.  So folks interested in this bug might want to report/fix it =
at <https://rt.cpan.org/Public/Dist/Display.html?Name=3DPod-Perldoc>.

________________________________________
Craig A. Berry
mailto:[email protected]

"... getting out of a sonnet is much more
 difficult than getting in."
                 Brad Leithauser