Thursday, May 24, 2018

Quickly making a DEB from a Perl module

Recently I had to quickly create a DEB package for Ubuntu for a Perl module available on CPAN (not sure why REST::Client is not available anymore).

It has been a while since the last time I did, and honestly I couldn't remember what was required to.

After some frustating minutes trying to go over the documentation for dh-make-perl, I was able to reach those two simple lines in a shell:

$ export DEBFULLNAME='Alceu Rodrigues de Freitas Junior'
$ dh-make-perl --cpan REST::Client --arch all --depends libjson-xs-perl, liblwp-protocol-https-perl, liburi-perl libwww-perl --email --build

Documentation of dh-make-perl does have a lot of space of improvement... and for my dismay, it is not even easy to do make contributions for it: no available access to the repository as you would expect to do nowadays (git pull request), first you got to be accepted as a Debian contribuitor... which is not that easy too.

Tuesday, February 27, 2018

Perl on Windows... still not that good

Today I had to use Perl from Windows... it was a couple of years that I needed to do it so.

Frankly, it was never the best experience from a end user point of view. Strawberry Perl made it a lot of easier, but still to this day it is still an incomplete solution.

Not about complaining... if you don't like a opensource project, don't use it. Or try to improve it yourself.

Here are some notes for those willing to do the later:
  1. Install Git for Windows. You will get some other nice programs as tar and gzip. You will need those and what the heck, everybody uses git nowadays.
  2. Configure the cpan program. You can use the default configuration offered and set some items later.
  3. Configure cpan to use the tar and gzip programs from step 1. In the case you don't remember, type o conf tar and o conf gzip and setup the complete path to those guys. If you were unwise and setup Git for Windows use the suggested path (C:\Program Files\Git), you will have to do some quoting and escaping the backslash (like "C:\\Program Files\\Git\\usr\\bin\\tar.exe").
  4. Configure cpan to use the gmake.exe program (don't really know why it wasn't configured by default, considering that gmake.exe is part of Strawberry Perl): o conf make C:\\Strawberry\\c\\bin\\gmake.exe
  5. Configure cmd.exe to use Unicode by default: fire up the command REG ADD HKCU\Console /v CodePage /t REG_DWORD /d 0xfde9 with administrator privileges in order to do that. It avoids you having warnings all over because of Unicode characters.
  6. Configure cpan to use a SQLite database (which speeds up the process): o conf use_sqlite 1
  7. Install YAML::XS, which is faster than YAML.
  8. Be smart and add C:\Program Files\Git\usr\bin to your PATH variable.

Sunday, January 28, 2018

cron versus Crom

Do you know cron? If you ever worked on a UNIX-like OS, it's very likely you do!

But what do you know about Crom?

What have they in common besides the (almost) identical names?

Let's see how the venerable cron compares to the imortal Crom!

cron Crom
What is it? Software time-based job scheduler for UNIX-like OSes. Fictional Cimmerian deity of Hyborian Ages.
Uses Schedule tasks to be executed, per user, with granularity of one minute. Basically nothing.
Some believe that he bestow men and women at birth with the courage to survive, persevere, and vanquish adversity.
Creation 1979 (Version 7 UNIX). 1932. Crom is the most venerable indeed.
Versions Several (proprietary, open source and free software) implementations. There is only one Crom, you hound dog son of a thousand fathers!
How to use it Executing crontab -e, or editing the several files that comprises it's configuration Invoke his name during an oath or curse. That's the only know safe way to mention him.
Known problems It will issue error messages if you messed up with the expected syntax He has little patience for weakness, which means asking him for help will make him to ignore you (at best) or really f@#$%&! you (at worst).

Thursday, September 28, 2017

Getting Ubuntu, Python 2.7, Jedi and Vim playing nice to each other

This took me some hours to figure out: how to finally set Jedi with Vim to have a good editor for Python 2.7 code.

Ubuntu 16.04 by default install Vim compiled against Python 3.5 interpreter, which is not immediate obvious but becomes a pain in the ass after you discover that even after installing Jedi and python-jedi, you're still getting the error message:

Please install Jedi if you want to use jedi-vim.

When opening a file with Python code.

To get things working for your Python 2.7 code, you might need to uninstall your current Vim related packages and install the following:
  • vim-addon-manager
  • vim-common
  • vim-gnome-py2
  • vim-gtk3-py2
  • vim-gui-common
  • vim-nox-py2
  • vim-python-jedi
  • vim-runtime
You can check your current configuration with:

$ dpkg-query -l 'vim*'

Thursday, July 6, 2017

Moving away from Dist::Zilla @Basic

Today a got an issue registered at my distribution Linux::Info and decided to take a quickly look at it since it was quite a while since the last release.

The issue itself was not that interesting (looks like the distribution Pod could receive some more attention, which indeed I added), but also gave me a chance to try and add a cpanfile to it.

Some months ago I was notified that my distributions were not providing a cpanfile. I wasn't even aware what was it about and what I was missing.

The thing is that a cpanfile is just another way to declare the distribution dependencies. Not really interesting from this point of view.

The good part of it is to allow the developer to install the distribution without having to install Dist::Zilla (and it's quite large number of dependencies) before even being able to build the distribution (well, assuming that the distribution uses Dist::Zilla).

That means you can skip some minutes and download bandwitdh, ignoring whatever Dist::Zilla depends on. Which also means you can just git clone a Perl project and install the requisites automatically with cpanm with two steps:

  1. git clone
  2. cpanm --installdeps .
That's it! Well, almost, you might need to install cpanm first. And be sure to include the dot in the step 2, it matters.

If your distribution uses Dist::Zilla already, you can add the cpanfile automatically by just adding [CpanFile] to the dist.ini file. The plug-in does the rest for you. Almost.

In order to have this cool stuff available from your code repository, you will need to have the cpanfile available over there... that means you need to build the distribution and copy the file to the repository, where it is going to be source controlled as everything else.

To cover that, you can use Dist::Zilla::Plugin::CopyFilesFromBuild, another plug-in to make your life easier.

But if you have the [@Basic] declared at the dist.ini (as I did) to load the most basic Dist::Zilla plug-ins you need, you will have a nasty surprise:

[DZ] attempt to add cpanfile multiple times; added by: GatherDir (Dist::Zilla::Plugin::GatherDir line 100); CPANFile (Dist::Zilla::Plugin::CPANFile line 65)

And the distribution generation is aborted. I was able to even find a bug registered about that, but it is not really a bug after all: it happens because the GatherDir, automatically registered by [@Basic], is not configured to ignore the cpanfile over there.

I tried to to that, but instead of getting rid of the error, I got a lot more of them, all of them related to GatherDir. Don't know why, but I was able to fix by removing [@Basic] and putting only the plug-ins I was indeed using and the over automatically included by the bundle and adding the following two lines to configured GatherDir:

exclude_filename = cpanfile

So, fixing the errors were a nice side effect of review what I indeed need in my distribution in terms of plug-ins.

Bottom line: Dist::Zilla::PluginBundle::Basic is great to start from scratch, but keep in mind that once your dist.ini is not that "basic" anymore, you will need to start cutting-off plug-ins!

Wednesday, April 19, 2017

Stop pestering me Yahoo!

I'm a user from Yahoo! from a long time ago already... something between 12 to 15 years.

For the most of the time, I can tell you I was a happy user... Yahoo! web interface was modern and I used it too with POP3 (later moved to IMAP of course) and SMTP with different e-mail clients.

From the last few years, well... we all know things are not good with Yahoo! anymore... Google took from it a good amount of the payed advertisement with it's (much more powerful) search engine. But from the past few months, the e-mail system is becoming a pain in the ass.

First, the SPAM filter doesn't work well. And I can't disabled it. I tried to refine it with some training but it seems it will be forever stupid because it keeps putting e-mails from mailing list that I'm subscribed for years in the SPAM folder.

Second, Yahoo! thinks my e-mail client is not secure anymore. Now and then, when I got check my e-mail on Thunderbird, I got a error message stating that the authentication process failed and asks me to try a different password. There is no password change, it is Yahoo! pestering me to stop using a e-mail client (yes, I tested with Claws too).

I didn't change my password, so let's go back to the web interface and see what is going on.

OK, it asks me my same old user and password. And this "nice" Captcha. And here is the reason for not being able to use Thunderbird:

For non Brazilian Portuguese speakers, it says:
"Alceu... disable the less secure access to your Inbox"
"Disable the applications that are not from Yahoo and that use methods of entering less secure to access the Yahoo Mail. If you don't do that, your account will be vulnerable"
Well... that's just bullshit. I use the same authentication method (Yahoo! doesn't asks me for a Captcha unless I got blocked first on my e-mail client) with Thunderbird, and also the connection uses TLS the same way that my browser uses.

Let's also add that I access it from my home network, that is behind a router/firewall, using a cabled connection (not WiFi) and that my PC uses a firewall as well.

What is considered secure as well? Their mobile application... that I should install on a Android, which I have little to no control (unless I got root on it) of how it works and the software that is installed and have to use WiFi or the shitty 4G available on Brazil.

Yeah, it doesn't look very secure too me so... STOP PESTERING ME Yahoo!

How to disable all logging from a Siebel component

You can change parameter to TRUE from the UI:

Here is default output from srvrmgr program:

srvrmgr:ssia811> list hidden param BypassHandler for comp EAIObjMgr_enu


------------- -------- ----------- --------- ------------- ------------- ---------------- ---------------- ---------------- ----------------- ---------------- ----------
BypassHandler False Boolean Subsystem Event Logging Default value Default value N N N N Do not send events to logging

1 row returned.

Here is the output after I changed from UI:

srvrmgr:ssia811> list hidden param BypassHandler for comp EAIObjMgr_enu


------------- -------- ----------- --------- ------------- ----------- ------------------- ---------------- ---------------- ----------------- ---------------- ---------
BypassHandler True Boolean Subsystem Event Logging Comp level Component level set N N N N Do not send events to logging
1 row returned.



  • This is will disable logging completely? Or the component log file will be created empty?

Setting BypassHandler to true will disable logging on component level there should be no logs.
  • This parameter can be enabled to other components? What are the restrictions?

You can enable same parameter for another components – no restrictions.
  • Is the output from srvrmgr "list hidden param" a bug?

It is not a bug, work this way as designed.