The Linux Page


Google understands the "Allow:" keyword in robots.txt

At times you have to prevent users from seeing files under a certain folder such as the /admin/ or /wp-admin/ folder.

The easiest way to at least avoid having Google index those pages is to add a Disallow line in your robots.txt file. For example:

Disallow: /admin
Disallow: /wp-admin

This is great and 99% of the time it does exactly what you want. Only once in a while a programmer does it wrong and places a file that should be searchable under such folders. For example, maybe someone placed a style.css file which is access by pages other than just pages under /admin. In that case, the ...

stream_socket_client() fails with no errors...

Today I had a weird one.

The PHP function named stream_socket_client(), used to create a socket to communicate with another computer over a network, may return $errno = 0 and $errstr = "".

The PHP reference actually mentions the problem:

On failure the errno and errstr arguments will be populated with the actual system level error that occurred in the system-level connect() call. If the value returned in errno is 0 and the function returned FALSE, it is an indication that the error occurred before the connect() call. This is most likely due to a problem initializing the socket. ...

Desktop Google Calendar now defaults to Agenda because I have it on my Android...

Since I got my Android phone earlier this year, I got a huge problem with Google Calendar.

I use the calendar mainly on my Desktop. Big screen, easy to read and use. But on the Android, the format is Agenda to make it possible to use at all.

Somehow that has a really bad side effect: the display is now always forced to Agenda on my Desktop too. Really annoying!

Tere is actually a very easy fix! It took me months the discover it and it's actually very easy.

I have the Calendar link bookmarked so I can just click one button to get it open.

All I had to do is add the following anchor at ...

Wordpress 2017 -- how do you get a summary in your Category and other lists?

I now also work on a Worpress website with theme 2017 (twentyseventeen) and I noticed that when I go to the Caegories or some other list of posts, I get the full posts.

Looking into it, I could not really see anything about it on the Internet. Strange.

The fact is that all you have to do is go back to each post (yeah, a tad bit tedious if you have hundreds already) and add the "Read more mark". The fact is that Wordpress does not seem to automatically add a feature to automatically calculte the summary of your posts. Maybe I missed it or I would need to install yet another plugin.. ...

REST hook trigger needs a polling url (ZSE007)

As I'm working on a Zap application (see Zapier). I got this error about my triggers:

REST hook trigger needs a polling url (ZSE007)

So... I understand that they want to have a URL to do a poll and they even have documentation that explains why they want to poll in case of a REST hook Zap: Whenever the user wants to test the Zap, the application will get some data using the polling method. That way they can get that data specifically for one test and not force you to generate an trigger. One problem with testing with an actual trigger is that any other Zap listening to the same trigger ...

My Embedded YouTube Video Disappeared

Embedded videos from used to work just fine on my website.

Today, though, I just noticed that my video was not showing up on one of my pages. Looking into it, I found out that the problem was the protocol.

I'm not too sure whether it was my browser or YouTube,com (although I'm not too sure how would know...) but the fact is that the iframe source was using HTTP and the page I was viewing used HTTPS.

By editing the page and changing the video from HTTP to HTTPS resolved the issue. It is generally much better to always use encryption anyway.

SugarCRM Community Edition for Ubuntu 16.04 with PHP 7

As I wanted to use SugarCRM on my new server, I looked into the Community Edition and apparently the company is not willing to convert their code so it works under PHP 7.

So that would not work on a newer system because the code uses quite a few forbidden mechanism (wrong class definitions, old defunct functions...) and that prevents to even instal the system on your machine.

Now, I have looked closer into it and I am getting a version that works pretty darn well already. I still have some issues here and there, but I think you can already make use of that version. Except for one thing which ...

Turning sites and modules on and off in Apache2

I always have to looks for the command line option to turn sites and modules on and off (really it is said to be enabled or disabled.)

The commands are as follow:

  • a2ensite -- enable one site
  • a2dissite -- disable one site
  • a2enmod -- enable one module
  • a2dismod -- disable one module

When you use one of the commands in the command line terminal without specifying which site or module to enable, then you are given a list of the sites or modules you can enable or disable. Note that the configuration files have to end with .conf for this mechanism to work as expected.

List ciphers currently used by Apache2

If you are using Apache and e-Commerce, you probably want to know all the details of the ciphers used by the Apache SSL module.

So listing Apache supported ciphers is done using nmap as follow:

nmap --script ssl-cert,ssl-enum-ciphers -p 443

This call gives you a complete list of all the ciphers currently accepted by your running version of Apache. For example, the list may look like this:

| ssl-enum-ciphers:
|   SSLv3:
|     ciphers:
|       TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA - strong
|       ...

Why would Redirect and RedirectMatch in Apache2 not work?

As we are working on a new website, we had a problem where a redirect would not work. I tried both: a simple Redirect and a RedirectMatch as follow:

Redirect /
RedirectMatch permanent ^(.*)$$1

Both of these entries would not work at all.

I verified, to make sure, that the alias module was turned on. It was.

ls -l /var/apache2/mods-enabled

This did list the alias.conf and alias.load entries as expected.

So? What else?

Well... This was installed on a new server and we left the default entry in there:

ls -l ...
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