Re^5: How to do perl -c inside perl?

Ok. I think I have gotten to the heart of it. And like other things of this ilk, it looks to me like a bug or misfeature.

I would have thought this would work:

package B::Syntax;
sub compile {
    return sub {
    $O::BEGIN_output =~ /Syntax OK/ ? exit 0 : exit 1;
    }
};
1;
[download]

And then call with:

   # $prog_or_e_option = ... ; 
   system("perl -MO=-qq,Syntax $prog_or_e_option");
   # Test $?
[download]

Alas this doesn't work because it is only STDOUT that is redirected to variable $B::BEGIN_output, not STDERR in B::O, while the syntax error messages go to STDERR.

I guess I will have to seek guidance from perl5-porters.

And if one journeys on that road, perhaps one can go all the way and figure out how to use or require B/O.pm inside Perl.

Comment on Re^5: How to do perl -c inside perl? Select or Download Code

Replies are listed 'Best First'.
Re^6: How to do perl -c inside perl? by rockyb (Scribe) on Aug 29, 2012 at 06:51 UTC
This works: `package Syntax; our $VERSION = '1.00'; use B qw(minus_c save_BEGINs); sub import { eval q[ BEGIN { minus_c; save_BEGINs; close STDERR; open (STDERR, ">", \$Syntax::stderr); } ]; die $@ if $@; } 1;` [download] And invoke like this: perl -MSyntax -e '1+' # gives non-zero return code perl -MSyntax -e '1+2' # gives zero return code perl -MSyntax my_program.pl When there is an error, that is captured in `$Syntax::stderr` above. The module could be extended to allow one to pass in a file name to write when there is an error. A still open question is to remove the "perl" invocation and have available `$Syntax::stderr`. do looks close, but is still a ways off. I may try to fill out the above and make a perl Module out of it.	[reply] [d/l]
Re^7: How to do perl -c inside perl? by rockyb (Scribe) on Aug 31, 2012 at 01:58 UTC
I've now dotted all the i's and crossed all the t's to make this a full-fledged package with tests and pod. That said, I am a little disappointed in the benefit of this over say `system("perl -c $program 2>/dev/null")`. Presumably it might work on more OS's. The main benefit I see putting this out there is for pedagogical purposes or for using this as a spring-board to do more — like avoiding the perl call altogether. Sigh. Sometimes life is like that. Better luck, next lifetime.	[reply] [d/l]