Re: Explicit interpreter paths considered harmful

[Jim Meyering]

Eric Blake wrote:
> According to Jim Meyering on 10/30/2009 2:52 AM:
>> FYI, this appears to work, both when invoked directly, and when invoked
>> as "perl gitlog-to-changelog ...", but I'm still on the fence...
>> Is it worth the ugliness, when invoking with $(PERL) is so easy, and
>> when the recommended usage is not to run them from the command line.
>>
>> diff --git a/build-aux/gitlog-to-changelog b/build-aux/gitlog-to-changelog
>> index a0f8a08..7f1880c 100755
>> --- a/build-aux/gitlog-to-changelog
>> +++ b/build-aux/gitlog-to-changelog
>> @@ -1,7 +1,9 @@
>> -#!/usr/bin/perl
>> +eval '(exit $?0)' && eval 'exec perl -wS "$0" ${1+"$@"}'
>> +  & eval 'exec /usr/bin/perl -wS "$0" $argv:q'
>> +    if 0;
>
> Wow.  That does start to get hairy.  But I think a script that can be run
> by both $(PERL) script and by ./script is worth the patch.  Why?  Because
> we should (eventually) support ./script --help, in case someone wonders
> why we included the script as part of the tarball and doesn't realize that
> it is normally a maintainer-only tool.

Ok.  Ludovic, if you can confirm that this works on all systems
you care about, then I'll commit it.

FYI, the above is verbatim from "man perlrun" but with added quotes
around each $0.