Showing posts with label perl. Show all posts
Showing posts with label perl. Show all posts

This Week I Learned 2018 - Week 16

Last week post or something from the archive.

看了一套墨西哥的戏,《行走距离》。电影讲述一个三百公斤的胖子,寄托于摄影以解生活的苦闷。间接中,也结交了几位好友,让他生命有所改善。没有惯性的情节,简单不过及现实的故事。健康是宝,平淡是福。

Another week of learning new English vocabulary. One issue with making sentences using these words was that the sentences was either too forceful or too literally (直译的) translated.
Sandy alleviates (缓解) the excruciating pain on her lower body part by elevating both legs into a bucket with warm water. By doing so, they hope it can obliterate (忘却) the pain she was going through. Both legs were swelling due to her falling into liquescent (易液化的) soil and stabbed by tree trunk while trekking in the wood. The swelling have worsen and everyone worry that the muscle may liquefy (使液化) from within. 

Stuck with an interesting MySQL problem, which was quite easy but I can't seem to get it right after several tries. Basically we want to update certain column in t1 to the maximum value from a group of similar records. The SQL query was quite straightforward, just join with the second table, t2 with maximum record with the first table, t1.
UPDATE t_transaction tu
JOIN (
    SELECT code, MAX(flag) AS flag
    FROM t_transaction
    GROUP BY code
) t
ON tu.code = t.code
SET tu.flag = t.flag

Modern backend developer in 2018? (via HN) A checklist and decision making tree are always a good choice to make good decision making when picking up new technology stack.

Perl constant array. Sometimes the simplest and easiest way is the only way instead of going through and abusing quirky Perl syntax.
use constant FRUITS => ['apple', 'orange', 'banana'];

my $fruit = 'apple';
if (!grep $fruit eq $_, @{+FRUITS}) {
    print "Is not a fruit";
} else {
    print "Is a fruit";
}

use constant FRUITS => qw(apple orange banana); 
use constant FRUITS => (apple orange banana);  
my $fruit = 'apple';
if (!grep $fruit eq $_, FRUITS) {
    print "Is not a fruit";
} else {
    print "Is a fruit";
}

Modern PHP without a framework. (via HN) Nah, still hate it after all these years. Maybe I'm just prefer a more prettier programming language.

回顾自己的工作生涯,真的必须自我检讨未来的工作方向,看看那些是自己重视的
所以,你得先釐清有哪些條件是你重視的,像薪水、公司品牌、職位、工作內容等,一一把它寫出來。列出條件後,再排定先後順序,之後,和你手邊的 offer(拿到手的工作)比較,做成表格。縱軸是你重視的條件,並依照先後順序,由上而下排列;橫軸則是你拿到的 offer。當你完成表格後,該選擇的工作就會自動「跳出來」。
當我們在思考應該向哪家公司投遞履歷時,其實已經在篩選公司了,但如果是以「錢多事少離家近」為標準,長遠而言卻未必是最適合自己的公司。所謂「知己知彼,百戰百勝」,此時應該要先釐清自己的需求,包括期望的上下班時間、喜歡的工作環境、想做內勤或外務、理想的管理方式、工作如何分配、會議如何進行、同事如何相處、以及有哪些學習機會等。再依這些喜好排出先後順序,然後評估要應徵哪些公司。
工作上要留下那个”人才“? 当然是人品态度优先,能力可以慢慢去培养。

What are some tech companies that do not use open floor plan? Interesting question for those who are looking to justify cubicles. The office at Fog Creek was in between, open space for collaboration and private office for working.

Data class in Python 3.7. (via HN) What took them so long? Syntactic sugar or not, this should have been in any fundamental data type for any programming that supports OOP.

Vipassana for Hackers. (via HN) A book on how a tech guy perceived and practiced Vipassana meditation without involving religion, just the practice. Contrary to typical meditation book, lots of pictures explaining the core concepts.

Moving for good. (via HN) Good write-up when you're moving to a new place. Key quote here (emphasis added),
Ask lots of questions. Ask them to explain things, and show you how it’s done. When they state a fact, ask how they know. When they state an opinion, ask for examples.
How to be a systems thinker. (via HN) I still can't get my head to understand this and the list of reading materials is quite long. Worth spend time on this? We shall see then.

This Week I Learned 2018 - Week 15

Last week post or grab something from the archive.

Travelling. Short and late write-up for this week.

一年一度的大自然环境“欣赏”周。水上活动总是有它的危险性。任何这类的活动都必须去注意团队的每个人的安全。如果一旦出现什么差错,到时要怪罪何人?关于个人安全,东方人及西方人的文化都明显都所差异。这是我们必须认真去检讨的。发展中国家的旅游胜地,虽然是经济的消费,但是也显出人民之间的贫富差距。罪该祸首还是不完善的教育体制,过于注重宗教而不注重论理學等知識。简单的算数,对某些孩子却是何苦艰难。

Travis CI and Perl. Some minor hiccup but I managed to get the Continuous Integration (CI) to work correctly. Unfortunately, I can't seem to find a way to test the CI within the local development environment.

The history of React.js. Didn't realize that React have came a long way, since 8 years ago. Yes, you got it right, 8 long years ago! The competition of the front-end Javascript libraries have settled down to either React, Angular, and Vue. Due to some "compelling" circumstances, this is a good time for "reacting" (pardon the pun), and nothing better to start with the fundamental basis (via HN).

"Manage your energy, not your time." How you manage your day (especially the morning) determine the productivity for the whole day, week, month, and year.

This Week I Learned 2018 - Week 07

Last week post or something else from archive.

Survived another Chinese New Year. Seems like a slow and lazy holidays, nothing much happening these days due to the slow economic. However, lots of catching up in my reading.

Something about my sedentary lifestyle. It seems I'm quite active on Thursday, Friday, and Saturday. Can't recall what I did during Thursday. Will keep monitoring this to bring awareness so I can reach on average, 6,000 steps per day.


Productivity is not equivalent to learning. Yes, as Won Cho discovered of one month of writing down everything he learned during code. You need to find a way to balance out and achieve both goals. The discussion in HN was more towards methods on learning like spaced repetition. One key insight was reading or scanning through site like HN is not learning, that is consuming information. Similar to digesting entertainment news. Similarly, my TWIL is just a journal of my notes of something that interested me and mindless rambling.

The Kubernetes Effect. (via HN) Again, containers is not silver bullet, just use a real PAAS and solve your business problem first (bring in the moolah!). Remember that an software architecture is a reflection of an organizational (which is really a communication) problem. Yes, we know it's very tempting to use the latest greatest stuff but seriously, do you really needs microservices? Are you Google or Facebook scale? If not, just stick to monolith architecture! Don't start with me on the complexity of front end development these days. While reading through the comments, I've learned that JEE application server is just an OS with containerized applications.

Have a few discussion with a local breeders. My observation leads me to believe some of these breeders only breed occasionally but also a reseller as well. They restock from larger Betta farms at a lower value (due to lower grade) and sell it at a margin for profit. But profit is quite limited just from selling fish unless you breeding for large volume or only exotic species. To compensate that, some breeders switched to sell accessories (nets, tanks, or medication) and aquatic live foods (blood worm, miona, vinegar eels, or others).

Betta fish or any ornamental fishes needs lots of attention and details. A slight overlook can either kill the fishes or even the whole spawn. We have lost four although we've procured eight more this week. Our initial investigation must be due to cross contamination due to sharing of aquarium siphons. The next step is to monitor the water parameters or switch to Indian almond leaves (lower pH and antibacterial property) or Banana leaves for all the tanks. We will wait and see how the new batch adapt to our new approach.

This Yahoo Answers post have gave the best advice I've read so far on Betta fish. We do agree with most of the the insights shared by the poster. Definitely a post to revisit from time to time.

If anyone going to ask me about MongoDB again. This will be my one sentence answer. It's a web scale database that successfully exploiting the "hype first, feature later" strategy. Yes, I just repeat what others said online again and again to deride MongoDB. Thinking of upgrading or using it, just wait for Jespen audit reports.

Curated list of Perl stuff. What the different? It's almost the same for all programming languages?

Dtrace switched from CDDL to UPL license. Too little too late?

Success in software project management? The quote below illustrates the insight succinctly (emphasis added). Or screw any methodologies, just follow the WhatsApp approach (YouTube video).
"small teams made up of scary-smart accountable people, given a well-articulated objective (not solution) and are left alone without distraction"

This Week I Learned 2018 - Week 05

Last week post or something from the archive.

New week and we're embracing the second month of 2018. The summer (for Southern Hemisphere, summer starts from December 1 till February 28 or 29) wind was blowing gently indicating the near of Chinese New Year. 活了大半辈子,原来南半球的季节正好跟北半球相反,真的是受教了!俗语说,“一年之计在于春,一日之计在于晨”, 自己要好好检讨及规划!

Going through my daily steps count, less activity this week due to sickness. Icy cold drinks during midnight and middle-age guy don't was not a good combination. But luckily we have long vacation, good to catch up with my needed rest and recovery. Comparison of total steps walked as illustrated below. (Yes I know the missing legend) Target for next week is to average out the steps till 5000 steps and above.


Dropsy and the whole body is pineconing? Nothing much we can do besides except humanely euthanize the fish. We lost three this week and unexpectedly the Blue Mable is going down also. The typical treatment is daily water changes combines with aquarium salt, Methylene blue, or Malachite green. We're not sure but I suspicious was due to overfeeding which leads to stress and constipation as well as infection.

When visited enough Aquarium shops, you will learn a thing or two. First, antibiotic powder (yellowish colour, suspect the main ingredient is Sodium Nifurstyrenate) usage was quite common especially expensive tropical fish like Discus (not a fan and seriously, a moving water pancake?!). Second, fish sellers in Market Road packed their fishes in plastic bags treated green water (suspect is Malachite green) and unpack it again in plastic square tank for selling each water in plain water. You can achieve profit if you can sustain the longevity of the fishes until they are sold to the customer.

More conversations breeders. It seems that female Bettas are far more expensive than male and fellow breeders don't want to sell their precious female Bettas to retain their quality breed of lines. Only for those who have financial gains from doing this. I wish more breeders should focus partially on the locally Malaysian Bettas. There is one breeder and I wish him all the best. Wild Bettas found locally may not be that colourful but it's good to breed and increase the population.

You know the play was so good that even the opposite bench players applauded it. This reminded me of Kobe Bryant's baseline reverse dunks. Along with Giannis AntetokounmpoBen Simmons is another NBA player to watch out for in the coming few years. Only time will tell.

Too many blockchain wannabe tech startups in Malaysia. Enough said. The never ending of startups chasing the next hype cycle.

How do you unstaged changes in Git? There are cases where merging or rebasing kind of messed up and you're left with a list of modified files.
$ git stash save --keep-index --include-untracked

Meanwhile, you can clean up your local working repository in Git through interactive mode or Git clean interactive.
$ git clean -di

The list reduction functions in List::Util. Some good examples:
$foo = reduce { $a > $b ? $a : $b } 1..10       # max
$foo = reduce { $a gt $b ? $a : $b } 'A'..'Z'   # maxstr
$foo = reduce { $a < $b ? $a : $b } 1..10       # min
$foo = reduce { $a lt $b ? $a : $b } 'aa'..'zz' # minstr
$foo = reduce { $a + $b } 1 .. 10               # sum
$foo = reduce { $a . $b } @bar                  # concat

More effed up stuff in our beloved MySQL. This time, "SQL Error (1451): Cannot delete or update a parent row: a foreign key constraint fails ....". To quote from the documentation (emphasis added),
If ON UPDATE CASCADE or ON UPDATE SET NULL recurses to update the same table it has previously updated during the cascade, it acts like RESTRICT. This means that you cannot use self-referential ON UPDATE CASCADE or ON UPDATE SET NULL operations. This is to prevent infinite loops resulting from cascaded updates. A self-referential ON DELETE SET NULL, on the other hand, is possible, as is a self-referential ON DELETE CASCADE. Cascading operations may not be nested more than 15 levels deep.

In other words, self-referenced foreign key(s) or recursive deletes doesn't work in MySQL (it WORKS in a PROPER database management system like PostgreSQL). You have to create another new table to link the relationship, something like many-to-many data model. If you needs deep nested hierarchy data structure, use Closure Table.

Looping and concatenating multiple arrays in Perl

Saw this code while searching through something and it caught my attention. Interesting way to concatenate arrays.
use strict;
use warnings;
use Data::Dumper;

my $a = [1,2];
my $b = [3,4];

my $c = [];
push @$c, @$_ for $a, $b;

print Dumper($c);

$perl main.pl
$VAR1 = [
          1,
          2,
          3,
          4
       ];

Alternatively, you can write it as this way where we concatenate both arrays.
use strict;
use warnings;
use Data::Dumper;

my $a = [1,2];
my $b = [3,4];

my $c = [];
push @$c, $_ for (@$a, @$b);

print Dumper($c);

$perl test1.pl
$VAR1 = [
          1,
          2,
          3,
          4
       ];

However, if we have any duplicate items in both $a or $b, it will be merged as well.
use strict;
use warnings;
use Data::Dumper;

my $a = [1,2];
my $b = [1,2,3,4];

my $c = [];
push @$c, $_ for (@$a, @$b);

print Dumper($c);

$perl test2.pl
$VAR1 = [
          1,
          2,
          1,
          2, 
          3,
          4
       ];

To resolve this, we need to remove the duplicate items in the combined array by using
List::MoreUtils.
use strict;
use warnings;
use Data::Dumper;
use List::MoreUtils qw(uniq);

my $a = [1,2];
my $b = [1,2,3,4];

my $c = [];
push @$c, $_ for uniq(@$a, @$b);

print Dumper($c);

$ perl test3.pl
$VAR1 = [
          1,
          2,
          3,
          4
        ];

This Week I Learned - 2017 Week 47

Last week post or random stuff from the archive.

Certain kind of food and my body does not like each other. Age related issue or just simple bad food? On the bright side, got the well deserved rest. More travelling. I can check off one item in my bucket list. Write it down and make it happen.

Never let an inexperience personnel to change your guitar strings. Sloppy works causing the guitar can't stay in tune. How to get the new guitar string to stay in tune then? Just two simple ways. Stretch all guitar strings either vertically (YouTube) or horizontally (YouTube). If this still fail, then you have intonation issue, which is quite tricky to fix or some other problems.

Numerous people have recommend Nujabes, some claimed he is the father of chillhop. Definitely worth adding this genre to your daily playlist.

The fake Facebook profile industry. (via HN). Even in the early days of IRC chat. Social engineering at its best.

What are some interesting papers in CS for a beginner? So many papers to read yet so little time.

Probably the biggest unnoticed item in the cloud right now. AWS have shifted the hypervisor used for the AWS cloud platform, from Xen to KVM. While is may seems like a blow to Xen but there is another new virtualization solution based on Xen called LightVM.

Example of implementing a web development stack based on microservices. (via HN) Overly and unnecessary complex? Perhaps but it serves as a good example of what can be done but not really recommended.

Don't have proper exception handling in Perl? Use eval() then. I finally grok this `eval()` thing in Perl. Example as shown below.
eval {
     # code that might throw exception
     1;  # always return true to indicate success
}
or do {
    # this block executes if eval did not return true (bacuse of an exception)

    # save the exception and use 'Unknown failure' if the content of [email protected] was already
    # removed
    my $error = [email protected] || 'Unknown failure';

    # report the exception and do something about it
};

"Just use jquery. In a few years jquery will be rediscovered and praised all over again." While I don't think this is possible but it's funny as hell.

Fricking annoying preview mode in Visual Studio Code. Disable it.

React control and uncontrolled form inputs. Good for beginner to start with React.

That really says a lots about Silicon Valley, especially the part on a peculiar form of McCarthyism.

This Week I Learned - 2017 Week 33

Last week post or the old ramblings.


The Vox POP is probably the most entertaining and educational YouTube channel right now. I wish they produce more and frequently.




Mommy, Why is There a Server in the House? Suitable for those who are active in /r/homelab.


Refurbished my battle station and upgraded my Fedora 25 to 26. Nothing special about this release and I was expecting something significant or may be I miss out something?
$ sudo dnf upgrade --refresh
$ sudo dnf install dnf-plugin-system-upgrade
$ sudo dnf system-upgrade download --releasever=26
$ sudo dnf system-upgrade reboot


Gigabyte MA10-ST0 powered by Intel® Atom C3958 SoC. A 16-core Atom (C3958 SoC) server board which can be a good server-based motherboard for virtualization or NAS. Think ESXi, FreeNAS, or Proxmox. I was thinking of buying and setting one up for data hoarding.


Does programmer needs office? Definitely. I still fail to understand why corporation still craze over open office floor plan. It's very hard to concentrate without any distraction. People walking by and talking non-stop. Collaboration doesn't means physical communication, it can be done through any messaging app. Private office does works. The funny thing is, I miss cubicle. At least you can really concentrate and work in the zone.


Unknown electronic parts? Get it from Octopart. Buying chips and checking availability? Find Chips.


Speaker broke down and I need to get a new pair of cheap bookshelf speaker. Initially was searching for a pair for good bookshelf speaker like Pioneer SP-BS22-LR, but unfortunately, this model have been either phased out or you have to purchase whole Hi-Fi set. Meanwhile, no local distributor is importing Micca PB42x. I read good review on Swan HiVi D1010-IV or Swan Hivi D1080-IV, might as well allocates budget to purchase this instead. Luckily we can still find it from the local supplier and the price still acceptable, within MYR 450-plus. All this discussion about cheap and good quality speaker is useless if you can't can't hear audio quality? Otherwise, you're just wasting money without any actual benefits.

When you have a pair of speakers, to get the best out of your 2.1 setup. The next purchases will a Digital Analog Conveter (DAC), which convert binary bits (zero or one) to analogue signal and a amp. If you have a DAC, you can skip buying a sound card. Popular DAC is Behringer UCA202 or UCA222 and for amp, Lepai 2020A+SMSL SA50Diagram below illustrates this setup.



Slow MySQL performance in Docker instance? Use TMPFS, where you put the whole database into the RAM. The approach for MySQL docker instance seems easy enough to setup and there have been many documented results.


Why are we trying hard to optimize the MySQL Docker instance? One of the main issue is that big database restoration may kill the MySQL daemon due to either large volume of records. Which begs the question, how many rows? This is determined by server parameter of `max_allowed_packet` or adjust the server according to these parameters.
- bulk_insert_buffer_size = 256M
- innodb_log_buffer_size = 64M
- innodb_log_file_size = 1G
- max_allowed_packet = 1G

While we're on MySQL, it seems we can delete records from two tables in one DELETE statement. The key thing here is the columns from both tables need to be specified.
DELETE a.*, b.*
FROM table1 a
LEFT JOIN table2 b
ON a.id = b.id
WHERE a.id = 1


It has been a while that I talked about Perl. Getting unique array list. Sigh, every single damn time I've encountered this I was wondering why this is not built into the core language itself?


GNOME is 20 years. It has been so long since I first tried it. I'm getting old. After Ubuntu switching to GNOME as default desktop environment, I felt that GNOME have finally won the GNU/Linux desktop war against KDE after so many fricking years.


No space life in Docker Machine in Windows? Maybe you can recreate another `default` Docker Machine following these settings. Assumed you're using VirtualBox.
$ docker-machine create
--driver virtualbox
--virtualbox-memory 8096
--virtualbox-disk-size 40000

This Week I Learned - 2017 Week 22

Last week's post or the whole series.

Slow week. Lots of pending stuff needs to be cleared off.

One of the best thing in learning, always be the most stupid person in a class and ask a lot of questions. You never know you will learn something new or relearn something old. Or it may reaffirm some beliefs you always held truly to yourself.

#1 If you need to display CJK characters and emojis in MySQL, use 'utf8mb4_unicode_520_ci'. Historically (another good write-up), MySQL support 'utf8mb3', later changed to 'utfmb4', and changed again to 'utf8mb4_unicode_520_ci' (since MySQL 5.7), and lastly 'utf8mb4_0900_ai_ci' (since MySQL 8.0). Sometimes you wonder why you still stuck with the curse of MySQL where there are better solution out there.

`utf8mb4` is the superset of `utf8`. Meaning that the former also includes the later character set.

To show the supported character set in your MySQL installation.

First check your MySQL version.
mysql> SHOW VARIABLES LIKE "%version%";
+-------------------------+-------------------------+
| Variable_name           | Value                   |
+-------------------------+-------------------------+
| innodb_version          | 5.7.18                  |
| protocol_version        | 10                      |
| slave_type_conversions  |                         |
| tls_version             | TLSv1,TLSv1.1           |
| version                 | 5.7.18-0ubuntu0.17.04.1 |
| version_comment         | (Ubuntu)                |
| version_compile_machine | x86_64                  |
| version_compile_os      | Linux                   |
+-------------------------+-------------------------+
8 rows in set (0.33 sec)

Next list our the available character sets for `utf8mb4`.
mysql> SHOW COLLATION WHERE Charset = 'utf8mb4';
+------------------------+---------+-----+---------+----------+---------+
| Collation              | Charset | Id  | Default | Compiled | Sortlen |
+------------------------+---------+-----+---------+----------+---------+
| utf8mb4_general_ci     | utf8mb4 |  45 | Yes     | Yes      |       1 |
| utf8mb4_bin            | utf8mb4 |  46 |         | Yes      |       1 |
| utf8mb4_unicode_ci     | utf8mb4 | 224 |         | Yes      |       8 |
| utf8mb4_icelandic_ci   | utf8mb4 | 225 |         | Yes      |       8 |
| utf8mb4_latvian_ci     | utf8mb4 | 226 |         | Yes      |       8 |
| utf8mb4_romanian_ci    | utf8mb4 | 227 |         | Yes      |       8 |
| utf8mb4_slovenian_ci   | utf8mb4 | 228 |         | Yes      |       8 |
| utf8mb4_polish_ci      | utf8mb4 | 229 |         | Yes      |       8 |
| utf8mb4_estonian_ci    | utf8mb4 | 230 |         | Yes      |       8 |
| utf8mb4_spanish_ci     | utf8mb4 | 231 |         | Yes      |       8 |
| utf8mb4_swedish_ci     | utf8mb4 | 232 |         | Yes      |       8 |
| utf8mb4_turkish_ci     | utf8mb4 | 233 |         | Yes      |       8 |
| utf8mb4_czech_ci       | utf8mb4 | 234 |         | Yes      |       8 |
| utf8mb4_danish_ci      | utf8mb4 | 235 |         | Yes      |       8 |
| utf8mb4_lithuanian_ci  | utf8mb4 | 236 |         | Yes      |       8 |
| utf8mb4_slovak_ci      | utf8mb4 | 237 |         | Yes      |       8 |
| utf8mb4_spanish2_ci    | utf8mb4 | 238 |         | Yes      |       8 |
| utf8mb4_roman_ci       | utf8mb4 | 239 |         | Yes      |       8 |
| utf8mb4_persian_ci     | utf8mb4 | 240 |         | Yes      |       8 |
| utf8mb4_esperanto_ci   | utf8mb4 | 241 |         | Yes      |       8 |
| utf8mb4_hungarian_ci   | utf8mb4 | 242 |         | Yes      |       8 |
| utf8mb4_sinhala_ci     | utf8mb4 | 243 |         | Yes      |       8 |
| utf8mb4_german2_ci     | utf8mb4 | 244 |         | Yes      |       8 |
| utf8mb4_croatian_ci    | utf8mb4 | 245 |         | Yes      |       8 |
| utf8mb4_unicode_520_ci | utf8mb4 | 246 |         | Yes      |       8 |
| utf8mb4_vietnamese_ci  | utf8mb4 | 247 |         | Yes      |       8 |
+------------------------+---------+-----+---------+----------+---------+
26 rows in set (0.00 sec)

However conversion from `utf8` to `utf8mb4` will encounter these issue of `ERROR 1709 (HY000): Index column size too large. The maximum column size is 767 bytes`. There is a DAMN good guide (ironically better than official documentation) written to resolve that issue and planning for the migration. However, the SQL queries only works for MySQL 5.6.

Meanwhile, this is one good example of writing Perl unit test cases to evaluate `utf8mb4` character set.

#2 Found the solution to my long unanswered question. When writing Bash script, how do we skip certain parameter. For example, we want to skip first parameter but takes the second $2 parameter onward? `shift` my friend. Is a universal concept that I've looked at it almost every day in Perl but never occur to me that this is the same in Bash script as well.

#3 PostgreSQL 10 with examples. The only worthy stuff produced by HP besides the printer. People, embrace the most advanced FOSS database system. Stop playing with MySQL.

#4 Time your console commands but cannot capture the output of `time` to a file? You're not using the command correctly. You should surround it with parenthesis. Either one will work. Depends on how many output files you want to have.
$ (time ls) > outfile 2>&1
$ (time ls) > ls_results 2> time_results

#5 How do you lost 1kg per week or the perfect diet? Both gave the same good advice. It actually make sense without actually starving yourself. The key take here is to first figure out the daily needed calories. Then reduce 500 calories from your food intake and add activities that burn 500 calories as well. The second part make sense. You just don't focus on diet, you should incorporate physical activities as well.

#6 "How do I get started with artificial intelligence?" and "What can I do with AI in my own product or company?" Read this.

#7 The technology stack of craiglist. Surprising, they are using Sphinx Search Server. Thought they might be using Elasticsearch. Why? Based on the comparison on both search servers, Elasticsearch scores way higher than Shpinx. Maybe Sphinx fits the requirement usages in craiglist?

This Week I Learned - 2017 Week 19

Last week post or the whole series.

Slow week but nevertheless, it was an interesting turn of event. Can't wait for more excitements to unfold in coming week. Importantly, never lose focus on your goals over petty things.

#1 One of the best experience shared I've read when comes to employment agreement. Always read the agreement carefully and lawyer up when necessary. Emphasis added by me.
I got sucked into a dispute with a former employer once over intellectual property rights in an employment agreement. They kept trying to sneak in a clause into the agreement in every other paragraph that gave them ownership of, full rights/responsibilities for, and access to, anything I did remotely related to programming or computers outside of work while not on the clock. It was so broad, even my non-lawyer ass knew it was an awful thing. It became a deadlock argument back and forth until I asked if they were accepting liability for any illegal activities I could perform outside of work. Suffice to say those clauses disappeared by CoB the next day in the agreement.
#2 Perl's answers to the Fizz-Buzz question.
#! /usr/bin/env perl
use strict;
use warnings;
use 5.024;

my $t = <>;
chomp $t;

for my $ins ( 0..$t-1) {
    my $limit = <>;
    my $sum = 0;
    map {
        $sum += $_ if ($_ % 5 == 0 or $_ % 3 == 0) 
        } 0..$limit-1;
    print "$sum\n";
}

What interested me is not the solution but the input from the diamond operator (<>) used within this context, which itself is also another interesting story. The diamond operator is useful when writing GNU/Linux console utilities as the operator will work either on standard input or files.

#3 Probably the best sequence diagram to illustrate an HTTP request through CGI. Source from Web Development with Perl.

#4 Why does Google prepend while(1); to their JSON responses? (via HN)

#5 Why you should just use PostgreSQL if you're using Open-sourced database systems? See the number of features (those in green) available. Sigh. Yet we still stuck with MySQL.

This Week I Learned - 2017 Week 18

Last week post or you want to read through the whole series.

Since the prevalent of Internet these days, we're more connected that ever. And yet, we're even more isolated. More and more shopping malls and residential areas are being built especially around the transit stations. Basically all looks the same and people are discourage to travel to another town anymore because everything is available either online or at your nearest malls.

Sick. Down with fever. It has been a while since last time. No one but myself to blame. For people around my age, good rest and food is a way to healthy life. We're not seeking prolonged life but prolonged health.

#1 So, what's your Plan B? Good discussion from the comments. While there is some sort of discrimination against older programmers, but the reality is older programmers may just burn out or bore doing the same mind-numbling stuff over and over again. Yes, the same sh*t but different day. Not everyone have the opportunity to work meaningful projects (yes, subjective view), but most of us just work on some glorified spreadsheet or database skin. You see the same mistakes repeated over and over again from different systems and it's just pointless or bother to raise it up again.

#2 On becoming a low-level programmer. There is a curated list of information especially on the hardware part.. There is also another list of learning the fundamental of computer science. So many things to learn and explore and yet, so little time. Sometimes the reality of life commitments limit our choice on the thing we want to pursuit. I need to finish everything by July before I can start to clear the list from my bucket list. One step at a time. Follow the system.

#3 First, make it work, then make it right, and finally, make it fast. Get the thing to work first before you're thinking about making it right (giving the right name) and optimize it. Fulfill the requirements of the stakeholders first (prototyping) before you're looking into doing it right and fast. Something I need to remind myself constantly as we're often obsess with perfection. What's the point if your build it the right way and fast but does not meet the stakeholder needs?

#4 How to write a REST client in Perl. Most Perl modules have limited documentation, for example, little example on how to use the APIs. This is where PHP (it has been so long since I mentioned something about PHP) really shines. As the language is slowing dying, there are little or no good example on how to start something up fast.

Meanwhile, something rather interesting about Perl. I've seen quite a few Perl codes with subroutines that prepended with ampersand (&) operator. Basically, the ampersand is needed if you're calling a subroutine before its declaration. Off course, there are many other reasons and usages to use the ampersand, but commonly as reference to a subroutine.
&hello;

sub hello {
    print "hello";
}

When using OO with Perl, you will need to instantiate the constructor or method invocation through the arrow (->) operator (a reference). Good examples given below.

Using the arrow notation or virtual method.
my $apple = Fruit->new("apple");
$apple->get_price('usd');

Using the double colons notation or static method.
my $apple = Fruit::new("apple");
Fruit::get_price($apple, "usd");

However, to invoke the method either statically or virtually, you'll need to write the constructor as follow.
sub new {
    my $self  = shift;
    my $class = ref($self) || $self;
    return bless {}, $class;
}

#5 "error: src refspec master does not match any." Silly me. You need to commit something locally before pushing to remote Git server.

#6 Tiny Python Notebook. Definitely not tiny but quite comprehensive guide to Python 3.6.

#7 How to unstage all staged files in Git? It's so easy that the best answer is not upvoted enough.
$ git reset

#8 Postgres Weekly. When come to FOSS database choices for web application for Intranet application, I'm strong opinion that PostgreSQL should be the default choice. Feature like Range Types and others solves quite a lot of issues and save lots of developer-hours. Yes, MySQL has its own usage, but for any business application which involves monetary and strong ACID compliance, it's not a right choice.

Sudoku Server

Interesting snippet of Perl code I've found. More complete version is found in Sudoku Garden.

Installing the required packages.
$ sudo apt-get install cpanminus
$ sudo cpanm ojo
$ sudo cpanm Spreadsheet::HTML
$ sudo cpanm Games::Sudoku::Component

Starting the application instance.
$ perl -Mojo -MSpreadsheet::HTML=sudoku -e "a('/' =>; {text =>; sudoku})->;start" daemon
Server available at http://127.0.0.1:3000



This Week I Learned - 2017 Week 17

Last week post or the whole series.

What happen to software developers who are still coding in their 40, 50, and 60?  What will happen in the next 22 years will be an interesting and unknown territory for older programmer to explore. There is always the case of how to do keep improving or how can we be a better programmerKaizen. Continuous improvement through through learning with understanding and stay healthy, both physically and mentally.

Complacency is your worse enemy when come to learning. We take it easy, do not dare to explore out of our comfort zone and afraid to look stupid. We know if we're heading this path, we will stuck forever, basically doing the same thing every year. Hence the developer with ten years experience but doing the same thing every year. Yet, we're afraid to start. Keep waiting for the right moment, the right motivation, and so no.

The older I get, the more I realized that motivation is fleeting and only discipline is reliable. Motivation is based on feeling where discipline is based on your habit. Best to cultivate good habits rather than waiting for the right feeling to come. Nothing but one step at a time.

#1 RIP Robert Pirsig. (via HN) Yes, he is the author of the cult book, Zen and the Art of of Motorcycle Maintenance. Interesting write-up on him during his day at spent in Banaras Hindu University (Varanasi, India).

#2 Good write-up on being a serious code reviewer. Only professional developer will take their code review session seriously as both parties, the reviewer and the code will learn something out of the session. The main obstacle is always how to handle it in a objective manner. Sometimes developer forget that you are (as a person) not your code. It's always a tricky situation.

#3 Sometimes, certain websites could change your life. No surprise some sites from are Ask Metafilter. All these reminds me of the web of the '90 and the time spent on aimlessly browsing through each pages. This is before RSS was even a thing yet.

#4 How many ways to execute your script parallelly? Three. Using wait, xargs, and GNU Parallel. The last one is the most comprehensive, featureful, and still being maintained.

#5 How Technology is Hijacking Your Mind. The prevalent tactics on manipulating our surfing behaviour. Throw in some dark patterns, we're basically somehow influenced to a certain agenda and direction. Given the ubiquitous Web and the Internet, how do we anticipate this manipulation? For a start, digital detox is a good start but still, this is not a long term solution, especially for those working in technology sector.

#6 Real-time Programming. (PDF) A course in learning about programming embedded real-time system.

#7 Is Perl still a good choice for web development? Yes and no. If you're not inheriting legacy Perl project, switch to something else more modern. If you're stuck with CGI, move to CGI alternatives like Mojolicious, Dancer2, Catalyst, or PSGI.

#8 Virtualization in GNU/Linux. Good introduction of different virtualization technologies available that we can use.

#9 The web is not desktop applications. Well said. Well said.

This Week I Learned - 2017 Week 16

Last week post or the regular whole series.

Minor hiccups due to sleeping schedule messed up my daily routine. Nothing but readjustment to get back on track. Switching different way of monitoring your habits did not produced the result needed. Furthermore, you should unwind during the weekend. If you need to use the Internet, write down the items you want to research instead of impulsively googling. Maybe I should just switch to dumb phone, nothing but for calls and SMS, like the old days. But it may not be a feasible solution and impractical.

#1 My whole development life in a circle where I have to encounter XXX again in the current development works. There is a write up on the origins of XXX as FIXME (via HN). Reason that we use XXX is easily greppable comment prefixes.

#2 How to handle Perl class-level variables. Two ways. (1) Lexical variable scoped (via subroutine) and (2) package variable. Simple concept that took me a while to finally realize and understand it.
# (1)
my $foo = 123;
sub get_foo { $foo }

# (2)
our $fubb = 456;

On a related note, found a list of Perl modules related to testing. There is so many modules that I haven't try out yet. So many things to try out, yet so little time.

#3 How do you remove all files except one? Seems hard yet so simple, if you know and remember how it works. Only on a rare instance you will encounter this. Typically we just move the file to different folder and delete the source folder.
$ shopt -s extglob 
$ rm -- !(file.txt)

#6 "If you haven't experienced true solitude yet, go find some. It's pretty grounding." (via HN) It's not a man against the wild but rather a man seeking himself through the solitude of nature. It has been so long that we ever lie down and look up the sky and enjoy the stars?

#7 "Colour is in the eye of the beholder". Interesting that our vocabulary influences how we perceive colours. Himba people have interesting vocabulary for colours, for example zoozu (dark colours and black), vapa (light colours and white), borou (green with blue and purple), dumbu (beige with yellow and some light green), and serandu (red with orange and pink). You can read more on this presentation, The Development of Color Categories in Two Languages: a longitudinal study.

#8 If you're facing problem with Google Chrome whenever you're opening new page but it took a while to load while waiting for "Resolving host...". Clear the DNS cache in Chrome. Seems to resolve the lagging issue for me and making browsing experience bearable.

This Week I Learned - 2017 Week 14

Last week post or you can go through the whole series.

Proposal have been presented and submitted. Standard feedback received. Nevertheless, better than nothing regardless the quality of the reactions.

#1 GTCafe Studio. Stumbled upon this site while searching for different covers of Guthrie Govan's Emotive Ballad. It's rare these days to find any blog with original good content. Reading through his journal on learning guitar made me reflect back on my decision on donating all my guitars away few years back. Maybe is time to start all over again? Or maybe not? Learning to play an musical instrument is one of the way to escape from mind-numbing daily routines. However, there is a time and place for everything in life. In hindsight, sometimes you just have to move on.

#2 "CentOS is not stable, it is stale". So true that it hurts. For me, as a whole, Fedora provides a better desktop experience than Ubuntu. Yet, I still revert back to Ubuntu on my daily usage. Why? APT is definitely better than YUM and plenty of software selection. Furthermore, LXD works only in Ubuntu and not Fedora. And yes, finally Canonical realized that and declared Ubuntu Unity will be replaced by Gnome 18.04 LTS. Maybe this Ask HN post on feedback for Ubuntu 17.10 from the community have finally sealed the fate for Unity?

I always wonder what would happen if Red Hat decided to use build a distro based on Debian or DPKG package manager instead of creating their own RPM packaging manager? A unified GNU/Linux desktop will come sooner rather than unnecessary fragmentation and efforts. For example, the competition of next generation display server of Mir and Wayland. Yes, I know having options and competitions is good for progress. But the priority and effort should be on fixing the damn display drivers performance and stability issues. Fragmentation leads to duplication of works.

#3 Five great Perl programming techniques to make your life fun again. An old article, 11 years ago but everything described there is as relevant as today especially iteration using `map` and `grep` and Dispatch Table as illustrated in example below. As Perl does not have `switch` statement, hence using Dispatch Table is a good Perl design patternMark Jason Dominus, in his book, Higher-Order Perl also devoted a whole chapter (PDF) on this matter.
my $dispatch_for = {
   a => \&display_a,
   b => \&display_b,
   q => sub { ReadMode('normal'); exit(0) },
   DEFAULT => sub { print "That key does nothing\n"; },
};

my $func = $dispatch_for->{$char} || $dispatch_for->{DEFAULT};
$func->();

#4 Perl 5 Internals (PDF). Interesting reading on the intricacy part of the Perl itself. It was brought to my attention that Perl is a bytecode compiler, not an interpreter or a compiler.

#5 The 'g' key shortcuts in Vim. You will learn something new everyday, there are so many key bindings. Surprisingly, I only knew and regularly use two. Really needs to refresh and relearn this.

This Week I Learned - 2017 Week 10

Last week post or just follow the whole series.

Got my result today. It seems I've officially "crossed" the borderlines stage. I'm still contemplating on the next step but drastic life style changes is inevitable (more in item #5). If left untreated, it can grow into bigger problems, not only for yourself, but for your loved one as well.

#1 You May Want to Marry My Husband (via HN). Beautifully written. We need to be constantly reminded of the fragility of life especially contemplating one's mortality. The lack of awareness will bite you and your loved ones somehow in the future. Over 30-something and still bogged down by random trivialities in life? Nothing but continual reflection on your life priorities (often misplaced) and gratefulness helps to make peace with current and past self. Regrets? Yeah, plenty. Who doesn't? But not to a point where you will lament later in life that you should, would, or could. Wish you've taken a different path? Nah. I'm good. Yes, there is still room for improvement. Looking forward to that.

Further reading. The 10 Best Modern Love Columns Ever.

#2 On Perl. Interesting thing learned. How do you clone a hash and at the same time, reassign new values to some of the existing keys? Simple and yet so effective. To explain this,  `%$foo` expands expands the hash into a key-value pair and the curly braces (anonymous hash constructor) will create a new hash reference. Output is from Devel::REPL module, the modern Perl interactive shell.
$ my $foo = {a => 1, b => 2, c => 3};
\ {
    a   1,
    b   2,
    c   3
}
$ my $bar = {%$foo, a => 4, b => 5}
\ {
    a   4,
    b   5,
    c   3
}

Instead of just doing this.
$ my $foo = {a => 1, b => 2, c => 3};
\ {
    a   1,
    b   2,
    c   3
}
$ my $bar = {%$foo};               
\ {
    a   1,
    b   2,
    c   3
}
$ $bar->{a} = 4;
$ $bar->{b} = 5;
$ $bar
\ {
    a   4,
    b   5,
    c   3
}

#3 Carton. Bundler for Perl. In other words, module dependency manager for Perl. Is Perl a lost cause that only a few diehard users still using and maintaining it? Seems likely to me.

#4 Ship daily. That probably the way to get your side project moving and don't feels like you're not completing anything. Can't do it? Maybe you're setting the bar too high and setting yourself up to failure. Of course, some are created to be thrown away. While I don't totally agree on the needs to to finish all your side projects, but when comes to actual paid work, we need rethink our role. Instead of a programmer, think yourself as a problem solver instead. A tiny shift of that mentality will get you closer to the deliverable.

#5 Getting older? Getting weaker? Maybe you should check your weight and measure your Body mass index (BMI)? If so, you should to readjust your diet. Stop eating like you're in college days. More (not just) portions of fruits and vegetables? Furthermore, be informed and mindful of what you put inside your body. Of course, exercise is needed as well. However, exercise alone does not lose weight. Joao Venture have experienced weight lost by reducing most of his sugar intake and maintaining 3 km daily walks per day. Using this calculator, 3 km is 3937 steps, rounded to 4000 steps. Those who works as software developer with sedentary life style, it's a struggle to reach 4000 on daily basis.

Looking through my steps count below, both my mean and median are roughly around 3000 to 4000 range. This fulfill at least one of the criteria. The next step is to adjust my diet by reducing my sugar intake. Interestingly, since the beginning of 2017, I only manage to hit 10000 steps only four times!


On a related note, sleep is also a crucial factor as well. What Kind of Sleeper Are You?

#6 The Unofficial MySQL 8.0 Optimizer Guide. The section on profiling is interesting and I really don't have time to go through each item on databases I'm working one. Definitely going to improve any legacy and messy databases.

#7 When comes to programming, some of us still missing the point that we're a problem solver first and a programmer second. Follow a process and the convention. Prioritize. Keep the solution simple (yes it maybe boring) and don't try to do things the fancy way unless really, really necessary.

This Week I Learned - 2017 Week 07

Last week post or the whole series.

When come to getting new stuff, I really should have a one-item policy. For example, if I'm going to get a new bag, either I sell off the existing bag or donate it out. Otherwise, no point having two bags where you only going to use one. Not only is wasteful, it's also a hassle to store it and clean it as well. Something for me ponder upon when I'm thinking of getting any new stuff.

#1 Six modern keys to wealth. HN user, monodeldiablo describes six possible ways for anyone to accumulate wealth. In essence, you should be competent (both book smart and street smart), persistent (perseverance), and extraordinary lucky (right place, right time, and right people).

Developers are generally book smart but always having difficulties to monetize their projects or technical ability (turn it into a business). The most recent example is JWE, the author and maintainer for GNU Octave is looking for job after 25 years of maintaining the software (I think he is doing a great job since he have been doing it for 25 years but having some financial difficulties these few years). I've made a small contribution to him and being a FSF associate member can help too (just make a note in your monthly contribution). Expect some blog posts on GNU Octave in coming future.

#2 Coroutines in Perl? Use Coro module. More on asynchronous programming in Perl in coming posts. Busy week and I can't seem to allocate any time to look into this. So many things to follow up and so little time.

#3 Prioritize! Prioritize! This reminds me of Stephen Covey's four quadrants approach (similar to The Eisenhower Method) of prioritizing to-do list and time management.

#4 theXeffect subreddit. Fundamental approach to build habits and prevent procrastination. Also known as the "Seinfeld Strategy". Following Bombjoke advice, the steps as follow.
  • Buy a pack of index card. Get the one from Daiso with 5mm grid.
  • Start with Boléro by Maurice Ravel as your background music.
  • Pick a daily habit you want to develop. May I recommend meditation?
  • Write the reasons on why you want to develop the habit on the back of the card.
  • Start now. Do the habit. Once done, mark a big 'X' on the box. If you fail, mark a big 'O'.
  • Continue for 66 days or 2 months. A habit is formed after that period.
The index card by hardcase00 shown below is a good example to illustrate the steps mentioned. Look closely at the card. In order to continue the streak, he have different minimum meditation time ranging from 5 seconds till 15 minutes. Set your goal so low and easy that you don't have any excuses of not doing it. Remember the main purpose is not to focus on how long you can meditate but to develop a habit of daily meditation.



#5 Software developers who started after 35. I have mixed feeling about this. Is good that anyone who are diligent enough can pick up software development skill but Peter Norvig's post on teaching yourself programming in ten years reminded me otherwise. Well, it depends on how you see software development itself. Is it a tool for your to achieve your goal? Or a skill you wish to gain and master? Different people have different motivations.

#6 Is PostgreSQL good enough? (via HN) By far, best written technical post I've read this year. Sad about the font size though. Seriously, who read at such small font size? I've seen quite a few systems which can benefit greatly if they switch to PostgreSQL instead of MySQL. MySQL, being popular and easy to learn doesn't means that it's suitable for all scenarios.There are other requirements where PostgreSQL fits, for example, PostGIS. For a comparison between two to programming languages, MySQL is like dynamic-typed programming language and PostgreSQL is like static-typed programming language. If I'm going to develop any intranet web application which involves critical financial information, my first choice is definitely PostgreSQL.

#7 Goals are for Losers. Passion is Overrated. Provocative opinion but make sense. You need to implement a system or habit to achieve what you want in life. Not passions or goals. Example from the slide is losing 10kg is a goal but eating the right way is a system. To increase the success of what you want in life, use a system approach to acquire more skills which can increase your odd. Summary of this approach. Item #4 is also another good example of systematic approach increasing the success rate of what you want to achieve in life.

This Week I Learned - 2017 Week 03

Last week post or the whole series.

#1 Having trouble finishing any personal side projects as a developer? Rethink the purpose on why you want to start a side projects? Don't be so hard on yourself, nobody is keeping scores and gives a crap. Do it because you want to learn, experiment, and have some fun along the way. However, keep the coding streak going. Don't overwhelmed yourself, it's not a full time job. Also, do not fall into the trap of researching more than doing ala analysis paralysis, a common behaviour when you're starting a new venture or hobbies and get overly excited.

#2 ShewhartJuran, and Deming. The giants of Total Quality Management (TQM) and theory. Humphrey applied these theories to software quality and thus, leads to the development of Software Engineering Institute (SEI), Capability Maturity Model (CMM), and Capability Maturity Model Integration (CMMI). Can quality theory used for manufacturing translates well to software development? Depends. Highly for embedded system development but doubt so for normal web development.

On a related note, can we apply these quality models and theories to our personal productivity and optimize our habits? If we consistently miss our commitments to our self, isn't that a symptoms of process failure? Hence, if we fix the process and thus fix our habits, can we increase the probability of the success of our commitments? Also can we apply CMMI's capability level to personal financial planning? That's food for thought. Again, this is a possible interesting idea, daily SCRUM family meeting. I've tried something similar with limited success. Feedback from SO is that it's too formal and too rigid.

#3 Keep up with fast changes of development field? Don't do front-end stuff. Don't follow the flash-in-the-pan (hot) technologies. Learn durable skills. Study and take online classes. Be a generalist? Don't think so. While we're still thinking on what hottest technologies or practices to use, ask yourself "when is practice X useful?" instead of "is practice X a good idea?" Good example is the numerous Agile practices, there are so many and not every one is applicable for your organization. One little gem I learned, Agile is used primary to solve communication or requirements issues. And also, another example of those practices is the use of monorepo, even through you're using a distributed version control system.

#4 T(Type) Driven Design over T(Test) Driven Design. Interesting indeed. Instead of embracing T(Test)DD, the problem can be partially solved by switching to a statically type programming languages. For example, switching from Python/Perl/PHP to Golang?

#5 While watching the short documentary series Mind Field on the subject on isolation, little I realized that boredom is the result of your brain lacking stimulation and worse, and epidemic psychological behaviour will little scientific studies.  Moreover, researches have identified that there are different types of boredom. Interestingly, Plutchik's wheel of emotions grouped the emotion of boredom with disgust and loathing. No wonder philosopher, Søren Kierkegaard said "boredom is the root of all evil" (or is it creativity?). How to prevent our self from succumb to boredom? Thinking about boredom itself, why something bores you. Or because we've become habituated? Maybe practice gratitude is an alternative way to resolve that?

#6 The Old School Object Oriented Perl (OSOOP). Yes, the bless-way. As I mentioned many times, specifically, Perl is a text processing programming language with multiple ways of doing things. Hence, OO supports is to the bare essentials, there is not syntactic sugar what so ever. If you're creating a CPAN module, best to use lightweight Moo package, which was designed for that purpose.

This Week I Learned - 2016 Week 51

Last week post or the whole series.

Week 51 of 2016. The last second week of the year. Lots of time to reflect and ponder about my past and future. Here is an video of interviews with three centenarians (those who live past 100 years) on their secrets for living so long. There maybe many years to go with your life but never overlook the issue of mortality. Learn as much as you can, do things you enjoy, and spend your time with someone who both of you are mutually care about.



List of single-file C/C++ libraries. Someone really needs to compile a bigger list. There are a lot that needs to be picked up by me when come to C++, mostly are all the fundamental stuff. Good example is do you know there are different types of memory allocated (stack, heap, bss, data, and text) for a program? That's why good fundamental of computing hardware is crucial being a system developer. Background on how Operating System works or manage the memory is something i severely lacking. Which is why I'm still having a hard time understanding the whole C++ compilation process (another good introduction with plenty of diagrams).

While we're on C++, if you are creating a new project, this can be the folder structure of the project you can follow. Between a macro, a function, or a class, just stick to something simple, use macro for creating debugging details.

Another interesting item caught my attention, conversion of other data type to string in C++ is not as straightforward as I assumed it is. There are many approaches, such as the standard C++ or C++03 way (using stringstream), the C++11 way (using std::to_string), or the Boost way (using boost::lexical_cast). Unless you're stuck with legacy C++ compiler, use the C++11 method. While we're looking at string, C++ being a static typed language, string manipulation have to be expressed in an explicit manner. For example, to pad a string to a certain size and characters as shown below.
std::cout 
<< std::left << std::setw(10) << std::setfill('.')
<< foobar << ": " << 42 << '\n';

// output
foobar....:42

Need to implement your own logging function? This is the time where you need to use a C++ macro. Otherwise how can you use the preprocessor macro like `__FILE__` or `__LINE__`?

Function pointer in C/C++. Useful when you have an array of items that point to a corresponding functions.

It has been a while since I ever look into PHP. Found two interesting libraries, Httpful and Underscore.php. Both are either direct port of influenced by similar libraries in other programming language. Not really sure about the current state of PHP but I glad I ended up doing something else other than PHP. It's always nice to code in different kind of programming languages.

Hook system in Perl? This needs a third party CPAN module like Hook::LexWrap. Otherwise, it can be quite hackish.

This Week I Learned - 2016 Week 50

Last week post or the whole series.

Two more weeks to go before we close the chapter for the year 2016.

Am I a good programmer? Think again, it's not just you but the remaining 99% of developers as well. The key point here is stop comparing, but instead identify the gap, and work out a plan to reduce the gap. This is doable provided that you realize what HN user, socmag advised that "...program if you enjoy it. Everything else will come. Financial reward is a side effect, not a cause.". Otherwise, just do something else. YOLO. Maybe rephrase the question, ask yourself, am I having fun? Need more advice? Read through similar discussions in HN.

Discipline is sustain through repeating a specific behaviour. How can we develop this systematically? Pick and develop ONE habit. Start small and start seriously. Don't overwhelmed yourself. Do it on daily basis and no more zero day. Anything is better than do nothing. Walking is better than sitting at the couch. Running is better than both. While we at it, get consistent sufficient sleep and rest. Try meditation to enhance your awareness and mindfulness as well. Follow the cue/craving -> response -> reward cycle suggested by Charles Duhigg. Do this for 66 days instead of the conventional 21 days. Also, another good write-up on building habit. Good luck!

Learning modern C++? So many resources, unfortunately, mostly are outdated and some still use Turbo C++. It seems C++ also suffered the same fate as Perl, hence, Modern Perl books was written. Then where can we obtain up-to-date information? Arne Metz suggested a few sites to check out for a start.
Follow up on implementing Full-text searching (FTS) in MySQL in week 48. The SQL example given there only suitable for searching exact keyword. What if you want to search partial word matching instead ala SQL LIKE operator? This is possible using asterisk (*) and BOOLEAN MODE modifier. Under this mode, the asterisk (*) is a wildcard operator, as in '%' in SQL. Example as shown.
SELECT name, MATCH(name) AGAINST('bio*' IN BOOLEAN MODE) AS relevance
FROM subjects
WHERE MATCH(name) AGAINST('bio*' IN BOOLEAN MODE)
ORDER BY relevance DESC
LIMIT 10

Something interesting on Git encountered this week. As I was git pulling the source, the unpacking process was so slow and I killed it with Control+C. The issue by doing this is that you've a lot of dangling commits or blob.
$ git fsck
Checking object directories: 100% (256/256), done.
Checking objects: 100% (540/540), done.
dangling blob f7c89a6a3fd135a16531bd776ecf04dcc9096cc1
dangling blob c66981a6cc4b877e1fe2064e6423c21831e308b3

To clear these dangling blob, you will need to clean up. Later I found out that unpacking was slow because there are a lot of binary files (graphic files) were added.
$ git gc --prune=all
Counting objects: 953, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (541/541), done.
Writing objects: 100% (953/953), done.
Total 953 (delta 392), reused 498 (delta 204)

Branching is cheap and free for SCM like Git. This is one concept I forgotten and during the last sprint, having two developers working on a single branch maybe not be a good idea unless both of you are can resolve conflicts correctly, do not rebase from master branch until testing, and squash your commit before merging as shown below.
$ git checkout featureX
$ git merge --squash featureX-dev1
$ git commit

Reflection on being a developer after 40. Most of the advices he gave were spot on especially choosing the galaxy (technology stack) wisely and open spaces office is crap. Yes, open collaboration my big foot, open noises would be the right description.

Learning Perl? Need to advance your Perl knowledge? Read Advanced Perl.