openssl/util/with_fallback.pm

#! /usr/bin/perl

package with_fallback;

sub import {
    use File::Basename;
    use File::Spec::Functions;
    foreach (@_) {
	eval "require $_";
	if ($@) {
	    unshift @INC, catdir(dirname(__FILE__), "..", "external", "perl");
	    my $transfer = "transfer::$_";
	    eval "require $transfer";
	    shift @INC;
	    warn $@ if $@;
	}
    }
}
1;
Refactor file writing - arrange for use of bundled Perl modules as fallback For our own convenience, we need a mechanism to be able to fall back on bundled Perl modules. It's a minimal package that's called like this: use with_fallback qw(Module1 Module2 ...); For each module, it will try to require them from the system installation, and failing that, it will temporarly add external/perl and try to require transfer::{ModuleName}. It requires that each bundled Perl modules is accompanied by a small transfer module (external/perl/transfer/ModuleName.pm in our example) that knows exactly what to load. Reviewed-by: Rich Salz <rsalz@openssl.org> 2016-01-22 19:37:31 +08:00			`#! /usr/bin/perl`

			`package with_fallback;`

			`sub import {`
			`use File::Basename;`
			`use File::Spec::Functions;`
			`foreach (@_) {`
			`eval "require $_";`
			`if ($@) {`
			`unshift @INC, catdir(dirname(__FILE__), "..", "external", "perl");`
			`my $transfer = "transfer::$_";`
			`eval "require $transfer";`
			`shift @INC;`
			`warn $@ if $@;`
			`}`
			`}`
			`}`
			`1;`