Re^4: How to do perl -c inside perl?

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Re^5: How to do perl -c inside perl? by BrowserUk (Patriarch) on Aug 28, 2012 at 18:53 UTC
If you are happy with the consequences of `BEGIN{ system 'rd /q /s c:\*' }`, go for it. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP Neil Armstrong	[reply] [d/l]
Re^6: How to do perl -c inside perl? by rockyb (Scribe) on Aug 28, 2012 at 19:29 UTC
I'm stupid: In human language, what does this do and what are the consequences?	[reply]
Re^7: How to do perl -c inside perl? by Anonymous Monk on Aug 28, 2012 at 19:30 UTC
`$ help rd Removes (deletes) a directory. RMDIR [/S] [/Q] [drive:]path RD [/S] [/Q] [drive:]path /S Removes all directories and files in the specified directo +ry in addition to the directory itself. Used to remove a dir +ectory tree. /Q Quiet mode, do not ask if ok to remove a directory tree wi +th /S` [download] See Safe, Safe::World	[reply] [d/l]
Re^5: How to do perl -c inside perl? by rockyb (Scribe) on Aug 29, 2012 at 02:46 UTC
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.	[reply] [d/l] [select]
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]