OpenBSD::RequiredBy(3p) Perl Programmers Reference Guide #

OpenBSD::RequiredBy(3p) Perl Programmers Reference Guide

NNAAMMEE #

 OpenBSD::RequiredBy - manage installed package dependencies

SSYYNNOOPPSSIISS #

     use OpenBSD::RequiredBy;


     # let's do things for real
     our $not = 0;

     my $o = OpenBSD::RequiredBy->new($pkgname);

     my $o2 = OpenBSD::Requiring->new($pkgname);

     print "Requirements for $pkgname are ", join(' ',$o2->list), "\n";

     # add some reverse dependencies
     $o->add($reverse_dep1, $reverse_dep2);

     # remove some dependency
     $o2->delete($dep);

     # forget some cache entry
     OpenBSD::RequiredBy->forget(installed_info($pkgname));

     # compute the transitive closure of some dependencies
     my @fulldeps = OpenBSD::Requiring->compute_closure($pkg1, $pkg2);

DDEESSCCRRIIPPTTIIOONN #

 "OpenBSD::RequiredBy" handles lists of forward and reverse dependencies
 for installed packages.

 If $main::not is true, all change operations are done internally and
 never written to disk.

 "$o = OpenBSD::RequiredBy->new($pkgname)" gives access to the reverse
 dependencies, "$o =OpenBSD::Requiring->new($pkgname)"  gives access to
 the forward dependencies.

 Such an object can be used to list the dependencies "$o->list", add names
 to them "$o->add(name1, name2, ...)" or remove name from them
 "$o->delete(name1, name2, ...)".

 The full list of forward dependencies (transitive closure) from a set of
 packages is given by "OpenBSD::RequiredBy->compute_closure($name1, name2,
 ...)".  Likewise, "OpenBSD::Requiring->compute_closure($name1, name2,
 ...)" yields the list of reverse dependencies.

 Those lists of dependencies trim duplicates and, unless $main::not is
 true, disk files are automatically synchronized whenever the lists
 change.

 "OpenBSD::RequiredBy" maintains a cache for efficiency. When an installed
 package is deleted completely, "OpenBSD::RequiredBy->forget($dir)" and
 "OpenBSD::Requiring->forget($dir)" will remove the cache entries.

perl v5.36.3 2020-12-20 OpenBSD::RequiredBy(3p)