About this series: A collection of short blog posts about lcpan tips/recipes. Some posts will also end up in the upcoming App::lcpan::Manual::Cookbook POD to be included in the App::lcpan distribution. First article is here. See the whole series.
About lcpan: an application to download and index a mini CPAN mirror on your local filesystem, so in effect you will have something like your own CPAN with a command-line tool (or perl API) to query and extract information from your mirror. I find it perfect for my own personal use when working offline.
lcpan remains as one of my most-used tools when doing Perl/CPAN development. I use it to search for modules to do some task (usually when I am offline or too lazy to open a browser tab to MetaCPAN, but also to do some grep-ing against the search results). I also use it sometimes to find modules related to a specific module, as keyword searches or seeing the SEE ALSO section of PODs are sometimes insufficient.
The following is a simplistic shell history analysis on how I use lcpan (on my main laptop, at least). The history I have on my laptop is from Nov 2017 to Jan 2019, so that more or less reflects how I used lcpan during 2018.
lcpan and lcpanm
% history | perl -lne's/.+?\]//; s/^pg //; next unless /^lcpanm?\s/; s/(^\S+).*/$1/; print' | freqtable
459 lcpan
332 lcpanm
I install modules from local mirror using lcpanm quite often.
PAGE_RESULT=1
"pg " is a shell alias which I define as:
alias pg='PAGE_RESULT=1'
because that lets me navigate the output of lcpan with a PAGER (which I have defined as 'less -FRSX').
Most often used subcommands
% history | perl -lne's/.+?\]//; s/^pg //; next unless /^lcpan\s/; s/(^\S+ \S+).*/$1/; print' | freqtable
175 lcpan mods
107 lcpan doc
35 lcpan scripts
32 lcpan deps
17 lcpan rdeps
16 lcpan related-mods
14 lcpan src
11 lcpan stats-last-index-time
10 lcpan upd
...
I use lcpan most often to:
- search for modules (lcpan mods);
- read documentation of modules which I don't have installed yet (lcpan doc);
- search for scripts (lcpan scripts);
- see dependencies (lcpan deps);
- see reverse dependencies (lcpan rdeps);
- search for related modules (lcpan related-mods);
- see source code of modules I don't have installed yet (lcpan src);
- checking the last update date of the index (lcpan stats-last-index-time);
- updating the mirror/index (lcpan upd which is shortcut for lcpan update).
Finding modules
% history | perl -lne's/.+?\]//; s/^pg //; next unless /^lcpan mods\s/; print' | sort -u
lcpan mods
lcpan mods average
lcpan mods average -l
lcpan mods average|wc -l
lcpan mods binary search -l
lcpan mods bitfin
lcpan mods bitflip
lcpan mods bitgrail
lcpan mods bloomberg
lcpan mods bluetooth
lcpan mods bluetooth -l
lcpan mods b perlstring
lcpan mods ccxt
lcpan mods cpan release
lcpan mods cpan release -l
lcpan mods DateTime::Format
lcpan mods DateTime::Format duration
lcpan mods DateTime::Format::Japanese
lcpan mods datetime iso8601
lcpan mods datetime iso8601 -l
lcpan mods dbi string
lcpan mods dbi string -l
lcpan mods dbi table
lcpan mods dbi table -l
lcpan mods Dist::Zilla::Plugin add -l
lcpan mods Dist::Zilla::Plugin:: --author PERLANCAR -l
lcpan mods Dist::Zilla::Plugin Module
lcpan mods Dist::Zilla::Plugin Module -l
lcpan mods eval
lcpan mods eval -l
lcpan mods fifo -l
lcpan mods File::Slurper
lcpan mods File::Slurper -l
lcpan mods finance crypto
lcpan mods float util
lcpan mods histo
lcpan mods histog -l
lcpan mods histogr -l
lcpan mods histo -l
lcpan mods inside eval -l
lcpan mods interpo
lcpan mods inventory
lcpan mods inventory -l
lcpan mods inventory|wc -l
lcpan mods -l array rank
lcpan mods -l bin groups
lcpan mods -l c encode
lcpan mods -l cli hub
lcpan mods -l compare
lcpan mods -l data cmp
lcpan mods -l dbi csv
lcpan mods -l dbix conn
lcpan mods -l dbix shortcut
lcpan mods -l freq table
lcpan mods -l groups
lcpan mods -l http tiny
lcpan mods -l list rank
lcpan mods -l module abstract
lcpan mods -l module info
lcpan mods -l module pod
lcpan mods -ln role
lcpan mods -l ord
lcpan mods -l ordina
lcpan mods -l ordinaq
lcpan mods -l permute
lcpan mods -l pod abstract
lcpan mods -l Regexp::Common::
lcpan mods -l Regexp::Pattern
lcpan mods -l return level
lcpan mods -l stock exchange
lcpan mods -l test2 tool
lcpan mods -l Test::Approximate
lcpan mods -l test compare
lcpan mods -l Test::Deep::
lcpan mods -l throttle
lcpan mods -l Tickit
lcpan mods -l Tickit Grid
lcpan mods -l tie array
lcpan mods -l Versioning dot
lcpan mods -l who
lcpan mods --namespace Acme::CPANLists
lcpan mods --namespace Acme::CPANLists -l
lcpan mods --namespace Acme::CPANModules -l
lcpan mods --namespace Acme::CPANModuless -l
lcpan mods --namespace Bencher -l
lcpan mods --namespace Bencher::Scenario
lcpan mods --namespace Bencher::Scenario -l
lcpan mods --namespace Data::Sah::Coerce::perl
lcpan mods --namespace Data::Sah::Coerce::perl::str
lcpan mods --namespace DateTime::Format
lcpan mods --namespace DateTime::Format -l
lcpan mods --namespace Graphics::ColorNames
lcpan mods --namespace Graphics::ColorNames|xargs lcpanm -n
lcpan mods --namespace Log::ger
lcpan mods --namespace Log::Ger
lcpan mods --namespace Log::ger|grep -i dump
lcpan mods --namespace String -l
lcpan mods --namespace WordList::Char
lcpan mods -n Archive::Tar
lcpan mods -n digit
lcpan mods -n digit -l
lcpan mods -n digit|wc -l
lcpan mods nearest -l
lcpan mods near -l
lcpan mods -n fifo
lcpan mods -n generic
lcpan mods -n generic -l
lcpan mods -nl Archive::Tar
lcpan mods -nl gen pw
lcpan mods -nl genpw
lcpan mods -nl pass gen
lcpan mods -nl pwd gen
lcpan mods -n pass gen
lcpan mods -n permute digit
lcpan mods Number::Format
lcpan mods Number Format -l
lcpan mods Number::Format -l
lcpan mods pass templat
lcpan mods pass templat -l
lcpan mods percent
lcpan mods percent Sah
lcpan mods percent|wc -l
lcpan mods perinci usage
lcpan mods perl release -l
lcpan mods permute lis
lcpan mods purchase
lcpan mods purchase -l
lcpan mods purchase price
lcpan mods python -l
lcpan mods qr decode
lcpan mods qr decoded
lcpan mods random norm -l
lcpan mods redact
lcpan mods regexp common
lcpan mods regexp common cc
lcpan mods regexp common credit
lcpan mods regexp common -l
lcpan mods ssh client -l
lcpan mods stack trace -l
lcpan mods stock
lcpan mods stock -l
lcpan mods stock|wc -l
lcpan mods Test::Deep:: -l
lcpan mods test path
lcpan mods Text::Histogram
lcpan mods time -l
lcpan mods time of day -l
lcpan mods timeofday -l
lcpan mods version dot
lcpan mods version scheme
lcpan mods version scheme|grep -v Google
lcpan mods who -l
lcpan mods WordList::CryptoCurrency::Catalog::Name
I do keyword searches a lot, and when the keyword is not specific enough I usually add "pg" and "-l" to let me navigate and search further with less. Sometimes I also do namespace searching (--namespace). I search for my own modules a lot, usually because I forget the exact name.
Finding related modules
Modules I tried to find related modules of:
% history | perl -lne's/.+?\]//; next unless /^lcpan related-mods\s/; print' | sort -u
; lcpan related-mods alias::module
lcpan related-mods Data::Diff
lcpan related-mods Data::Throttler
lcpan related-mods Data::Valve
lcpan related-mods IO::Tee
lcpan related-mods Number::Tolerant
lcpan related-mods Package::Alias
lcpan related-mods String::JS
lcpan related-mods Test::Deep
lcpan related-mods utf8
Finding scripts
% history | perl -lne's/.+?\]//; s/^pg //; next unless /^lcpan scripts\s/; print' | sort -u
lcpan scripts bin -l
lcpan scripts count
lcpan scripts count -l
lcpan scripts dateconv
lcpan scripts dateconv -l
lcpan scripts envres
lcpan scripts group -l
lcpan scripts histogram -l
lcpan scripts http-tiny
lcpan scripts interval
lcpan scripts interval -l
lcpan scripts lineno
lcpan scripts linenum
lcpan scripts line number
lcpan scripts lino
lcpan scripts linum
lcpan scripts -l org2html
lcpan scripts -l org-to-html
lcpan scripts parse-nik
lcpan scripts parse-nik -l
lcpan scripts parse num
lcpan scripts _pause
lcpan scripts perl
lcpan scripts perllint
lcpan scripts pick
lcpan scripts pick -l
lcpan scripts pick-l
lcpan scripts rand
lcpan scripts rand -l
lcpan scripts resolution
lcpan scripts resolution -l
lcpan scripts throttle
lcpan scripts zodiac -l
I search for my own scripts a lot too, since I have almost a thousand (~880) of them on CPAN. It's a bit challenging trying to keep the naming organized. When tab completion doesn't help, lcpan comes to the rescue.
