The Linux Page

Help other users realize that everything is possible, especially avoiding Windows for their own personal use.

Welcome to The Linux Page


Fox Trot by Bill Amend. Click to enlarge.
Click to enlarge

This site is a collection of my own work with Linux. Certain things are easy, others take time to decipher and if I ever need to repeat the work (which usually happens!), then I need to remember everything by memory or... have a site with all the steps taken and to take again.

The following are my most recent posts:

Drawing of the Wolf Susie.Jinx

Problem since Ubuntu 13.10

As I upgrade to 13.10 of Ubuntu, I'm having to do work to get my system back to normal...

Today I stumble on the fact that USB ports are now not accessible by everyone by default. So when I tried to scan a document, it told me that I had no scanners. Panic... and then I found out that the permissions were changed, widely, so only users who are root (by default) can access the scanners.

I changed the group to a group I'm in and it worked without having to reboot or relog in. However, it is not unlikely that the group won't stick... Ah! Correct! But ...

A bee extracting pollen from a flower

Today I was thinking that I'd like to have a way to include my list of Jira issues in my Debian packages so users can see that list if they'd like to know where we're at. (what's left to do)

Looking around, I found nothing of interest that said:

Extract Jira issues from the Command Line

So I tried with other types of searches and found a few things, but no real command line tool. Well... it looks like there is one from the Jira people but I'm afraid that's Java and I did not understand what the command could be (i.e. all I could see was a list of what looks like a ...

Dead tree in a desert, how it feels when you try to start a daemon and it doesn't

Today I wanted to test a service directly on my developer system. That is, I wantedto start it with systemd to prove that it was working (it does not work right on a full install, though.)

I bumped in a few problems, though.

Aug 23 09:32:38 halk systemd[1]: snapwatchdog.service: Main process exited, code=exited, status=200/CHDIR

First, I got this cryptic error. I though that "CHDIR" would mean that when systemd tries to change directory, it wasn't happy. Sure enough, that was it. I have an entry which tells systemd what my Current Working Directory should be:

 ...

The padlock of an old barbed wired gate

A Permission Problem

Today I noticed an error in my mail.log file about maildrop, a postfix tool, having permission problems.

The errors look like this:

Aug 22 20:58:01 snapwebsites postfix/postdrop[18189]: warning: mail_queue_enter: create file maildrop/255899.18189: Permission denied
Aug 22 20:58:01 snapwebsites postfix/postdrop[12347]: warning: mail_queue_enter: create file maildrop/524431.12347: Permission denied
Aug 22 20:58:11 snapwebsites postfix/postdrop[18189]: warning: mail_queue_enter: create file maildrop/258810.18189: Permission denied
Aug 22 20:58:11 snapwebsites ...

So many locations, you need many variables... or instead think of using one common location and find yourselves quickly every time

We have a large project named Snap! C++ which uses cmake to compile everything. It is clear that cmake is the right solution, I don't question that part even one minute. It would be a killer to try to use any other system.

Our environment is pretty large with many libraries, daemons, tools, plugins, scripts... all organized in sub-projects of one large project named snapwebsites. For example, we have the libsnapwebsites library and the snapmanager sub-projects. However, as far as cmake is concerned, this is but one project.

So?

Well... to give you a concrete example, we have a file in ...

Address book, BIND and is an electronic address fast.

BIND Quoted String Support

I noticed a lack of description of the BIND support for strings in their documentation.

Unfortunately, there are many flags in their parser so truth be told, they support many different cases. First of all, some of the files that they parse do not support quoted strings at all. So I wanted to document what is supported:

No Strings

As I just mentioned, some files do not support strings at all. In that case, the double quote (") character is likely to be viewed as a character on its own.

Also "master" defines the double quote character as a ...

Rocket launch--installation of a service automatically starts that service under Ubuntu

Problem

In our snapwebsites.org environment, we install many daemons.

Most of these daemons are expected to be started as soon as they get installed even if they can't really run properly. For example, the snapserver needs a valid connection the snapdbproxy which requires Cassandra to be ready for the purpose. It still works since snapserver waits on a CASSANDRAREADY signal (sent by snapdbproxy through snapcommunicator.) While waiting, daemons are sleeping so they use their normal share of memory, but no CPU at all.

Now, a few of our daemons need to not be started by default. We ...

Today I got to work on a document including a few expressions (multiplications and a sum.) That was in a table that looked something like this:

Designation Price Quantity Total
Stuff #1 $10 3 $30
Thing #2 $20 0.5 $10
Other #3 $30 4 $120
Grand Total: $160

In my case, I made a copy/paste of such a table and I went ahead and deleted Thing #2 and Other #3 because I did ...

From a full hard drive to about 20% usage! All due to our MySQL script using the front host IP address.

One of our computers was setup to delete rows from a database. Anything older than 90 days should be deleted. Only the script to run that DELETE had the incorrect IP address and we weren't watching the database closely so it grew to over 107 million rows and on a small VPS that filled up the hard drive.

At that point, trying to run the DELETE command would generate this error:

ERROR 3019 (HY000) at line 1: Undo Log error: No more space left over in system tablespace for allocating UNDO log pages. Please add new data file to the tablespace or check if filesystem is full or enable ...

A bunch of fruits on a table with five smoothies

Unix in Colors

Whenever I run a command without piping it through less, I generally get colors.

This is true in this century that computer started to use more and more colors in the console. It's practical for all sorts of reasons.

However, you lose those nice colors when you want to use "less" to paginate the results. There are two reasons for that:

Terminal vs. Pipe

The fact is that many tools will check their stdout and determine whether it's a terminal or not. If not, it can generally be assumed that it's a file, a pipe, a variable, etc. and therefore a ...

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