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CPAN::Mirrors - Get CPAN mirror information and select a fast one


use CPAN::Mirrors;

my $mirrors = CPAN::Mirrors->new( $mirrored_by_file );

my $seen = {};

my $best_continent = $mirrors->find_best_continents( { seen => $seen } );
my @mirrors        = $mirrors->get_mirrors_by_continents( $best_continent );

my $callback = sub {
    my( $m ) = @_;
    printf "%s = %s\n", $m->hostname, $m->rtt
$mirrors->get_mirrors_timings( \@mirrors, $seen, $callback, %args );

@mirrors = sort { $a->rtt <=> $b->rtt } @mirrors;

print "Best mirrors are ", map( { $_->rtt } @mirrors[0..3] ), "\n";



Create a new CPAN::Mirrors object from LOCAL_FILE_NAME. This file should look like that in .


Return a list of continents based on those defined in MIRRORED.BY.

countries( [CONTINENTS] )

Return a list of countries based on those defined in MIRRORED.BY. It only returns countries for the continents you specify (as defined in continents). If you don't specify any continents, it returns all of the countries listed in MIRRORED.BY.

mirrors( [COUNTRIES] )

Return a list of mirrors based on those defined in MIRRORED.BY. It only returns mirrors for the countries you specify (as defined in countries). If you don't specify any countries, it returns all of the mirrors listed in MIRRORED.BY.

get_mirrors_by_countries( [COUNTRIES] )

A more sensible synonym for mirrors.

get_mirrors_by_continents( [CONTINENTS] )

Return a list of mirrors for all of continents you specify. If you don't specify any continents, it returns all of the mirrors.

You can specify a single continent or an array reference of continents.

get_countries_by_continents( [CONTINENTS] )

A more sensible synonym for countries.


Returns the default mirror, . This mirror uses dynamic DNS to give a close mirror.


best_mirrors checks for the best mirrors based on the list of continents you pass, or, without that, all continents, as defined by CPAN::Mirrored::By. It pings each mirror, up to the value of how_many. In list context, it returns up to how_many mirrors. In scalar context, it returns the single best mirror.


how_many      - the number of mirrors to return. Default: 1
callback      - a callback for find_best_continents
verbose       - true or false on all the whining and moaning. Default: false
continents    - an array ref of the continents to check
external_ping - if true, use external ping via Net::Ping::External. Default: false

If you don't specify the continents, best_mirrors calls find_best_continents to get the list of continents to check.

If you don't have Net::Ping v2.13 or later, needed for timings, this returns the default mirror.

external_ping should be set and then Net::Ping::External needs to be installed, if the local network has a transparent proxy.

get_n_random_mirrors_by_continents( N, [CONTINENTS] )

Returns up to N random mirrors for the specified continents. Specify the continents as an array reference.

get_mirrors_timings( MIRROR_LIST, SEEN, CALLBACK, %ARGS );

Pings the listed mirrors and returns a list of mirrors sorted in ascending ping times.

MIRROR_LIST is an anonymous array of CPAN::Mirrored::By objects to ping.

The optional argument SEEN is a hash reference used to track the mirrors you've already pinged.

The optional argument CALLBACK is a subroutine reference to call after each ping. It gets the CPAN::Mirrored::By object after each ping.

find_best_continents( HASH_REF );

find_best_continents goes through each continent and pings N random mirrors on that continent. It then orders the continents by ascending median ping time. In list context, it returns the ordered list of continent. In scalar context, it returns the same list as an anonymous array.


n        - the number of hosts to ping for each continent. Default: 3
seen     - a hashref of cached hostname ping times
verbose  - true or false for noisy or quiet. Default: false
callback - a subroutine to run after each ping.
ping_cache_limit - how long, in seconds, to reuse previous ping times.
    Default: 1 day

The seen hash has hostnames as keys and anonymous arrays as values. The anonymous array is a triplet of a CPAN::Mirrored::By object, a ping time, and the epoch time for the measurement.

The callback subroutine gets the CPAN::Mirrored::By object, the ping time, and measurement time (the same things in the seen hashref) as arguments. find_best_continents doesn't care what the callback does and ignores the return value.

With a low value for N, a single mirror might skew the results enough to choose a worse continent. If you have that problem, try a larger value.


Andreas Koenig <>, David Golden <>, brian d foy <>


This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.