Perl Weekly Challenge 038: Date Finder and Word Game

Date Finder

Create a script to accept a 7 digits number, where the first number can only be 1 or 2. The second and third digits can be anything 0-9. The fourth and fifth digits corresponds to the month i.e. 01, 02, 03…, 11, 12. And the last 2 digits respresents the days in the month i.e. 01, 02, 03…, 29, 30, 31. Your script should validate if the given number is valid as per the rule and then convert into human readable format date.


  1. If 1st digit is 1, then prepend 20 otherwise 19 to the 2nd and 3rd digits to make it 4-digits year.
  2. The 4th and 5th digits together should be a valid month.
  3. The 6th and 7th digits together should be a valid day for the above month.

For example, the given number is 2230120, it should print 1923-01-20.

As we’ve done several times, we’ll use the core module Time::Piece to handle dates.

Some 10 Year Stats. recently turned 10 years old. I was curious about the level of traffic so grabbed all of the post URLs and meta information to create the lists below. These are accurate up until the posting of this post (excluding this post):

  • Total Posts: 8,091
  • Total Posts (2016 Onwards): 2,595
  • Total Unique Authors: 676
  • Authors With Only 1 Post: 246

Most Active Authors (All Time):

  • byterock - 604
  • jt_smith - 442
  • ovid - 382
  • sawyer_x - 304
  • brian_d_foy - 227
  • steven_haryanto - 160
  • yuki_kimoto - 153
  • ron_savage - 148
  • joel_berger - 132

Most Active Authors (2016 onwards):

  • byterock - 417
  • sawyer_x - 138
  • yuki_kimoto - 93
  • dean - 72
  • mohammad_s_anwar - 69
  • melezhik - 66
  • zoffix_znet - 65
  • ovid - 59
  • neilb - 55

Most Active Months:

  • 2012-07: 163
  • 2010-08: 134
  • 2012-04: 128
  • 2011-10: 121
  • 2014-03: 121
  • 2013-02: 119
  • 2012-05: 118
  • 2012-03: 117
  • 2010-07: 114
  • 2011-11: 111

Total Post Count By Year:

  • 2009 - 116
  • 2010 - 1,023
  • 2011 - 1,094
  • 2012 - 1,274
  • 2013 - 1,006
  • 2014 - 983
  • 2015 - 542
  • 2016 - 535
  • 2017 - 459
  • 2018 - 664
  • 2019 - 395

Perl Subroutine Signatures Opinion Blog

I have great respect for Perl developers.

I am always grateful for the work.

On the other hand, I have a very strong concern in the future of Perl.

I created a site for my opinions on subroutine signatures so that themes would not be missed in the discussion.

Perl Subroutine Signatures Opinion Blog

I have no final authority. I pray Perl developers make a good decision.

Apache SpamAssassin 3.4.3 has been released!

Apache SpamAssassin 3.4.3 contains numerous tweaks and bug fixes as we prepare to move to version 4.0.0 with better, native UTF-8 handling. There are a number of functional patches, improvements as well as security reasons to upgrade to 3.4.3. In this release, there is also one new plugin and there are bug fixes for two CVEs:
  • CVE-2019-12420 for Multipart Denial of Service Vulnerability
  • CVE-2018-11805 for nefarious CF files can be configured to run system commands without any output or errors.
*** On March 1, 2020, we will stop publishing rulesets with SHA-1 signatures. If you do not update to 3.4.2 or later, you will be stuck at the last ruleset with SHA-1 signatures. ***


See also

Paws XXXV (Well not a wrap but close)

Well it looks like a wrap for Paws S3

I made up my own test creation caller. No rocket science in this one. I just added in a few useful attributes;

Type::Tiny 1.8.0 released

Type::Tiny 1.8.0 (1.008000) was released today.

The new features are pretty minor. Most of the improvements are in documentation and testing.

  • Totally rewritten manual/tutorial.

  • Every issue on RT has been handled.

  • Bigger test suite. The exact number of tests run varies based on the availability of optional dependencies, but I just ran the test suite with EXTENDED_TESTING set to false and most of the optional dependencies installed, and it was nearly 7500 tests, compared to just over 2700 for Type::Tiny 1.6.0. With EXTENDED_TESTING true, there are nearly 13900 tests.

    This includes a set of tests for each built-in type which are intended to function both as test cases and advanced documentation.

Why is the specification of subroutine signatures so complicated?

As a general Perl user who uses Perl for text processing on Linux, I have a simple question.

Why is the specification of subroutine signatures so complicated?

Jumbo Signatures extensions discussion

The most common criticism of Perl is that it cannot read Perl grammar.

If Perl grammar evolves in an easy-to-understand direction, you are welcome.

If you are going to increase the complexity blame for Perl, think a little more.

Is this feature really useful for users who want to do text processing on Linux/Unix?

A single language cannot satisfy every need.

I have not yet seen what purpose Perl is aiming for.

CPAN Testers at meta::hack v4

For this year's MetaCPAN Hackathon, I decided I wanted to start turning the CPAN Testers mockup I made 3 years ago into a real, working site. Along the way, I built a much better development environment for CPAN Testers, making it even easier for someone to start working on the project. I also released Mojolicious::Plugin::Moai, a UI widget kit for Mojolicious.

Thanks to cPanel and for their continued sponsorship of this event!

Rewriting Perl Code for Raku IV: A New Hope

Part IV starts to get into the heart of OLE::Storage_Lite by covering the pack/unpack builtins.

Perl Weekly Challenge 037: Weekdays and Daylight Gain/Loss


Write a script to calculate the total number of weekdays (Mon-Fri) in each month of the year 2019.

I used the core module Time::Piece and its companion from the same distribution, Time::Seconds. Let’s start on the first day of the month, and keep adding one day while we stay in the same month. Along the way, count the days that aren’t Saturdays and Sundays.

Perl Weekly Challenge 37: Week Days in Each Month and Daylight Gain/loss

These are some answers to the Week 37 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days (December 8, 2019). This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

Challenge # 1: Week Days in Each Month

Write a script to calculate the total number of weekdays (Mon-Fri) in each month of the year 2019.

Paws XXXIV (Yet more code)

Well after spending a little while trying to create an auto test generator I found the test generator script that came with PAWS.

So I decided to try it out. With only a little fudging of the code internals, no real code changes just changes to libs, I got it to work;

perl script/paws_make_testcase  S3 --region us-east-1 GetBucketLocation Bucket: "dev.cargotel.test"

the test file it generated /0001.response.test.yml;

  - expected: eu-west-2
    op: eq
    path: LocationConstraint

So that is ok.

However when I opened the caller file '0001.response' it contained only JSON;

Working with CSV files using PDL

Ahh, the venerable comma separated variable format, beloved of data scientists.

I grabbed a couple of csv files from Matt Pettis’ csvkit talk to prepare for the datafile that I should be getting my mitts on and tripped and bumped my way through the documentation for PDL::IO::CSV and metaphorically skinned my knees, as you do when you don’t read too carefully.

Constant Platypus

A common challenge in calling C functions from any language other than C or C++ is dealing with constants. In C these are usually implemented using #define pre-processor directives which are lost by the time the code is linked into a dynamic library. (In fact it is lost before the source is even compiled, since it is a pre-processor directive). For example, the libarchive library provides these constants in its header file for dealing with errors:

 * Error codes: Use archive_errno() and archive_error_string()
 * to retrieve details.  Unless specified otherwise, all functions
 * that return 'int' use these codes.
#define ARCHIVE_EOF       1     /* Found end of archive. */
#define ARCHIVE_OK        0     /* Operation was successful. */
#define ARCHIVE_RETRY   (-10)   /* Retry might succeed. */
#define ARCHIVE_WARN    (-20)   /* Partial success. */
/* For example, if write_header "fails", then you can't push data. */
#define ARCHIVE_FAILED  (-25)   /* Current operation cannot complete. */
/* But if write_header is "fatal," then this archive is dead and useless. */
#define ARCHIVE_FATAL   (-30)   /* No more operations are possible. */

Rewriting Legacy Code in Raku III: The Sourceror

Part III in the series talks about functions, prototyping, and some of the tweaks you'll need to make while transferring Perl code to Raku

Asking for Rakudo.js grant feedback

Work on the Rakudo.js grant has been completed and now I'm add the stage where community feedback is needed. It would be super grateful for Your feedback. You can provide it in blog comments on this post.
The final grant status update is available HERE

Perl Weekly Challenge 36: Vehicle Identification Numbers (VIN) and the Knapsack Problem

These are some answers to the Week 36 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Task # 1: Vehicle Identification Numbers (VIN)

Write a program to validate given Vehicle Identification Number (VIN). For more information, please checkout wikipedia.

From the Wikipedia article, it appears that VINs are made up of 17 digits and upper-case letters, with the exception of letters I (i), O (o) and Q (q), to avoid confusion with numerals 0, 1, and 9. There are some additional rules that only applicable to certain areas of the world but are not internationally recognized.

Vehicle Identification Numbers in Perl 5

We write a simple validate subroutine that returns a true value (1) if the passed parameter complies with the above rules for VINs and a false value (0) otherwise.

Monthly Report - November

November was the quietest month for me. I would give credit to the book Why We Sleep, gifted by Neil Bowers. I haven't finished reading the book yet but whatever I read so far made a big difference. A very big THANK YOU to Neil. I no longer do late nights, technically that means no work after midnight for me. However I do wake up early on weekends and finish the pending work. One more change, I noticed that I don't visit MetaCPAN very often. Earlier I used to checkout every 30 minutes during the day. But now I do it once every couple of days. Having done 160 Pull Requests in October, then doing only 51 Pull Requests in November feels so light. In fact I reached my monthly target of 50+ Pull Requests in the third week of November. Last one week was relaxing, I made conscious efforts not to look for Pull Request.

By Any k-Means Necessary

You want to get to know your data, questions like, can they be broken down into a simple set of classes. You don't know what these classes might be, so your task is clustering and you reach for one of the oldest clustering algorithms around k-means.

k-means is popular because it's simple to understand, converges fast, works in higher dimensions and gives you an answer. It's also usually the wrong choice unless you've already got nicely clustered data just waiting for you to guess k, the most appropriate number of clusters to answer your question. But it is a decent warm up exercise in becoming friends with your data set.

Perl 5 development has moved to Github

I didn't notice much public discussion, but in the last month, Perl 5 development has moved to Github. The logistics of the move were mostly handled by Todd Rinaldo although I'm sure there were other people helping.

The change involved moving the main development repository from to, moving the issues from to Github issues, renaming them in the process, and fixing the code that used the hostnames or URLs for decisions.

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