A tip: sometimes you install stuff from source and library search order makes analyzing which library you are actually using a mess. A useful tool is ldconfig -p that will print the cache of the dynamic linker for you allowing you to understand which libraries are actually being used.
Sometimes you want to write a shell or other script, and that script is going to have to run under sudo. Under such conditions if the script does anything that requires authentication it will not act as expected. In plain terms it means that the regular popup for authentication will not appear. The tool maybe [...]
Ever written the occasional Perl script and wanted to insert the current date and time into a MySQL database? Here is the function to do it. This works for a column of type ‘datetime’. 1 2 3 4 5 6 # function to return the current time in mysql format sub mysql_now() { my($sec,$min,$hour,$mday,$mon,$year,$wday, $yday,$isdst)=localtime(time); [...]
When you buy a new computer or get one and you are not sure of the quality of memory that it has, or when you buy, upgrade or add new memory you should test it before going on to simply use it. The reason is quite intricate. In most probability the memory with will either [...]
In a struggle to secure my home computer I did battle with the ssh server once again to configure it “just the way I want it” ™. I prefer pubkey + password since this ensures that if I lose the laptop/phone/whatever then the lucky finder will not find his/her way into my home computer. So, [...]
There is much accumulated wisdom in the embedded systems programming field as to how to correctly write a real time application. Examples of this wisdom could be found in the methodology of breaking up the application to a startup phase and a run phase, avoiding exiting the application, avoiding dynamic memory allocation and deallocation at [...]
In the past couple of weeks I have been dabbling with command line to tag and inspect tags of mp3 files. Linux has an abundance of tools to fill this niche and it’s confusing to know what to use. What follows are my conclusions. id3: only handles 1.1 tags. id3v2: does not handle 2.4 tags. [...]
I sometimes need to find all broken symbolic links in a folder, recursively or not. find(1) is the all UNIX right tool for the job as far as finding files is concerned but it does not have an explicit -and -type brokenlink option… Some solutions involve sending the output of find(1) to some other tool. [...]
I recently found some issues with the openjdk Ubuntu/Debian default Java implementation. Specifically I had issues with their web start support (javaws). I found that the Sun implementation of Java did not have such a deficiency and the Sun implementation is available through the regular Ubuntu/Debian package sources. I installed the Sun implementation and wanted [...]
When upgrading my Ubuntu system my /etc/fstab got overwritten by the upgrade process. It seems that the new /etc/fstab file did not keep my old preferences for file systems. I didn’t notice this for some time but what I did notice was that my system was sluggish. After some time I recalled that I had [...]