CPAN::Visitor - Generic traversal of distributions in a CPAN repository
version 0.003
use CPAN::Visitor; my $visitor = CPAN::Visitor->new( cpan => "/path/to/cpan" ); # Prepare to visit all distributions $visitor->select(); # Or a subset of distributions $visitor->select( subtrees => [ qr{D/DA}, qr{A/AD} ], # relative to authors/id/ exclude => qr{/Acme-}, # No Acme- dists match => qr{/Test-} # Only Test- dists ); # Action is specified via a callback $visitor->iterate( visit => sub { my $job = shift; print $job->{distfile} if -f 'Build.PL' } ); # Or start with a list of files $visitor = CPAN::Visitor->new( cpan => "/path/to/cpan", files => \@distfiles, # e.g. ANDK/CPAN-1.94.tar.gz ); $visitor->iterate( visit => \&callback ); # Iterate in parallel $visitor->iterate( visit => \&callback, jobs => 5 );
A very generic, callback-driven program to iterate over a CPAN repository.
Needs better documentation and tests, but is provided for others to examine, use or contribute to.
my $visitor = CPAN::Visitor->new( @args );
Object attributes include:
cpan -- path to CPAN or mini CPAN repository. Required.
cpan
quiet -- whether warnings should be silenced (e.g. from extraction). Optional.
quiet
stash -- hash-ref of user-data to be made available during iteration. Optional.
stash
files -- array-ref with a pre-selection of of distribution files. These must be in AUTHOR/NAME.suffix format. Optional.
files
$visitor->select( @args );
Valid arguments include:
subtrees -- path or array-ref of paths. These must be relative to the 'authors/id/' directory within a CPAN repo. If given, only files within those subtrees will be considered. If not specified, the entire 'authors/id' tree is searched.
subtrees
exclude -- qr() or array-ref of qr() patterns. If a path matches any pattern, it is excluded
exclude
match -- qr() or array-ref of qr() patterns. If an array-ref is provided, only paths that match all patterns are included
match
all_files -- boolean that determines whether all files or only files that have a distribution archive suffix are selected. Default is false.
append -- boolean that determines whether the selected files should be appended to previously selected files. The default is false, which replaces any previous selection
The select method returns a count of files selected.
select
$visitor->iterate( @args );
jobs -- non-negative integer specifying the maximum number of forked processes. Defaults to none.
jobs
check -- code reference callback
check
start -- code reference callback
start
extract -- code reference callback
extract
enter -- code reference callback
enter
visit -- code reference callback
visit
leave -- code reference callback
leave
finish -- code reference callback
finish
See "ACTION CALLBACKS" for more. Generally, you only need to provide the visit callback, which is called from inside the unpacked distribution directory.
The iterate method always returns true.
iterate
Each selected distribution is processed with a series of callback functions. These are each passed a hash-ref with information about the particular distribution being processed.
sub _my_visit { my $job = shift; # do stuff }
The job hash-ref is initialized with the following fields:
distfile -- the unique, short CPAN distfile name, e.g. DAGOLDEN/CPAN-Visitor-0.001.tar.gz
distfile
distpath -- the absolute path the distribution archive, e.g. /my/cpan/authors/id/D/DA/DAGOLDEN/CPAN-Visitor-0.001.tar.gz
distpath
tempdir -- a File::Temp directory object for extraction or other things
tempdir
stash -- the 'stash' hashref from the Visitor object
quiet -- the 'quiet' flag from the Visitor object
result -- an empty hashref to start; the return values from each action are added and may be referenced by subsequent actions
result
The result field is used to accumulate the return values from action callbacks. For example, the return value from the default 'extract' action is the unpacked distribution directory:
$job->{result}{extract} # distribution directory path
You do not need to store the results yourself -- the iterate method takes care of it for you.
Callbacks occur in the following order. Some callbacks skip further processing if the return value is false.
check -- determines whether the distribution should be processed; goes to next file if false; default is always true
start -- used for any setup, logging, etc; default does nothing
extract -- extracts a distribution into a temp directory or otherwise prepares for visiting; skips to finish action if it returns a false value; default returns the path to the extracted directory
enter -- skips to the finish action if it returns false; default takes the result of extract, chdir's into it, and returns the original directory
visit -- examine the distribution or otherwise do stuff; the default does nothing;
leave -- default returns to the original directory (the result of enter)
finish -- any teardown processing, logging, etc.
These allow complete customization of the iteration process. For example, one could do something like this:
replace the default extract callback with one that returns an arrayref of distribution files without actually unpacking it into a physical directory
replace the default enter callback with one that does nothing but return a true value; replace the default leave callback likewise
have the visit callback get the $job->{result}{extract} listing and examine it for the presence of certain files
$job->{result}{extract}
This could potentially speed up iteration if only the file names within the distribution are of interest and not the contents of the actual files.
Please report any bugs or feature requests using the CPAN Request Tracker web interface at http://rt.cpan.org/Dist/Display.html?Queue=CPAN-Visitor
When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.
App::CPAN::Mini::Visit
CPAN::Mini::Visit
Please report any bugs or feature requests through the issue tracker at http://rt.cpan.org/Public/Dist/Display.html?Name=CPAN-Visitor. You will be notified automatically of any progress on your issue.
This is open source software. The code repository is available for public review and contribution under the terms of the license.
https://github.com/dagolden/cpan-visitor
git clone https://github.com/dagolden/cpan-visitor.git
David Golden <dagolden@cpan.org>
This software is Copyright (c) 2010 by David Golden.
This is free software, licensed under:
The Apache License, Version 2.0, January 2004
To install CPAN::Visitor, copy and paste the appropriate command in to your terminal.
cpanm
cpanm CPAN::Visitor
CPAN shell
perl -MCPAN -e shell install CPAN::Visitor
For more information on module installation, please visit the detailed CPAN module installation guide.