Slash Boxes
NOTE: use Perl; is on undef hiatus. You can read content, but you can't post it. More info will be forthcoming forthcomingly.

All the Perl that's Practical to Extract and Report

use Perl Log In

Log In

[ Create a new account ]

pudge (1)

  (email not shown publicly)
AOL IM: Crimethnk (Add Buddy, Send Message)

I run this joint, see?

Journal of pudge (1)

Thursday June 05, 2008
02:54 PM

Stupid Slash Tricks: Auto-Encapsulation of Tasks

[ #36597 ]

The slashd program in slash runs "tasks" which are separate files. It performs a require(). The problem is that sometimes symbols in each task can conflict with another.

We have many tasks so rather than edit each one, we decided to handle the encapsulation in slashd itself. It creates a package name, and has code to import symbols from main into the package, and then sets the line number correctly.

        (my $tmppackage = $file) =~ s/\.pl$//;
        $tmppackage =~ s/\W/_/g;
        $tmppackage =~ s/^([^a-zA-Z])/a_$1/g;
        $tmppackage = "Slash::Task::$tmppackage";
        # replace tmppackage in string where appropriate
        (my $addtxt = <<'EOT') =~ s/\${?tmppackage}?/$tmppackage/g;
package $tmppackage;
{ no strict 'refs';
    my @scalar = qw(me task_exit_flag);
    my @hash   = qw(task);
    my @code   = (qw(
            slashdLog slashdErrnote slashdLogDie
            tagboxLog verbosity db_time init_cron
        grep { *{"main::$_"}{CODE} }
            @Slash::EXPORT, @Slash::Display::EXPORT,
            @LWP::UserAgent::EXPORT, @URI::Escape::EXPORT,
            @File::Basename::EXPORT, @File::Path::EXPORT,
            @Time::Local::EXPORT, @Time::HiRes::EXPORT
    *{"${tmppackage}::$_"} = *{"main::$_"}{HASH}   for @hash;
    *{"${tmppackage}::$_"} = *{"main::$_"}{SCALAR} for @scalar;
    *{"${tmppackage}::$_"} = *{"main::$_"}{CODE}   for @code;
#line 1
        my($tmpfh, $tmpfile) = tempfile();
        my $tmptxt = do { open my $fh, '<', $fullname; local $/; <$fh> };
        print $tmpfh $addtxt, $tmptxt;
        $tmpfh->flush; # can't close fh until we require the file,
                       # else the file might disappear
        my $ok = 0;
        eval { local $me = $file; $ok = require $tmpfile };

Cross-posted on <pudge/*>.

The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
More | Login | Reply
Loading... please wait.