ExtUtils::PerlPP 1.2219

ExtUtils::PerlPP is a Perl Preprocessor.

SYNOPSIS

use ExtUtils::PerlPP;
my $config = { version => $VERSION,
driver => $DRIVER };


# The long and winding road ...
my $self = ExtUtils::PerlPP->new();

$self->{in_fh} = IO::File->new(file.PL, r);
$self->{out_fh} = IO::File->new(file, w);
$self->{config} =

$self->parse();


# And now a short cut for the same:
ppp(file.PL, file, $config);

Perls installation suite, ExtUtils::MakeMaker, contains a mechanism for installing preparsed files, so-called PL files: If the MakeMaker utility detects files with the extension .PL then these files are executed by make, usually creating a file of the same name, except the .PL extension.

Writing these PL files is usually always the same, for example a typical .PL file might look like this:

my $script = <<SCRIPT;
... # True file following here
SCRIPT

# Modify variable $script, depending on configuration, local
# site or whatever
...

if (!open(FILE, ">file") || !(print FILE $script) ||
!close(FILE)) {
die "Cannot write file: $!";
}

But in essence, what else is this than a Perl preprocessor?
Traditionally you have to write such a Perl preprocessor for yourself all the time, although I have found that they always do the same, for example:

-

Fix defaults, for example installation paths.

-

Including or excluding code sections. It is a matter of taste whether one likes to see

if ($] < 5.003) {
# Thirty lines of code following here
...
} else {
# A single line of code
...
}

when already using Perl 5.005. I dont.