Andrea Leofreddi's blog

The Olimex USB-serial-cable - a 3.3v USB-to-serial adapter based on the PL2303XA chip - won't work out of the box on macOS. While there are various drivers out there in the wild, my...

Some time ago I wrote a post on how to brew and manage multiple (Adopt)OpenJDK versions on your mac - which is my current java setup. Premised so, lately I wanted to install...

AWS Cognito is a great tool to chop-off authentication from your app, with a lot of bonuses when it comes to single sign on and integration with existing directories, but the web console...

Using homebrew It's super easy to install any JDK version from the adoptopenjdk builds: Andreas-Mac-mini:installer a.leofreddi$ brew tap AdoptOpenJDK/openjdk ==> Tapping adoptopenjdk/openjdk Cloning into '/Users/a.leofreddi/Applications/homebrew/Library/Taps/adoptopenjdk/homebrew-openjdk'... remote: Enumerating objects: 24, done. remote: Counting objects:...

On Mojave, I ran into a situation while trying to install CryptX via CPAN: "/usr/bin/perl" -MExtUtils::Command::MM -e 'cp_nonempty' -- CryptX.bs blib/arch/auto/CryptX/CryptX.bs 644 "/usr/bin/perl" "/System/Library/Perl/5.18/ExtUtils/xsubpp" -typemap '/System/Library/Perl/5.18/ExtUtils/typemap' -typemap '/Users/a.leofreddi/.cpan/build/CryptX-0.063-EfIC0d/typemap' CryptX.xs > CryptX.xsc mv CryptX.xsc...

Lately I've been gluing some Java+Netty code with a C++ native library, and I wanted the native C++ code to use Java's logging too (in this case the ubiquitous slf4j framework). So, let's...

In the meantime... a.leofreddi@XXX's password: Last login: Thu Oct 13 17:26:12 UTC 2016 from YYY on pts/0 Last failed login: Sat Oct 29 12:23:42 UTC 2016 from ZZZ on ssh:notty There were 135084...

Often (and especially when scanning documents with my printer) from MacOSX I would get unreasonable huge PDFs which are not suitable for emails. To strip them down without pain one can use ghostprint:...

Today I wanted to setup ssh yubikey authentication for a CentOS 7 box, and I've lost more time that expected. Since I've found a lot of wrong documentation I'm posting below the correct...

TimEL is a Java library specifically developed to evaluate time-series expressions using a user-friendly language. Check out the new version which comes a new streaming API allowing it to crunch very large amounts...

If you look around on the internet you may find a lot of blogs guiding you on the installation of Jetty in RHEL 7 (or CentOS) which require you to download a new...

Back in the 90s I used to hang out on irc, and there, for many years, I’ve used the cyberz nickname, hence cyberz.org. But life goes on and a lot of things changed...

Sometimes you may want to override the default SELinux context for a given path. This can be easily accomplished editing adding an entry (which is made by a path regexp and the selinux...

While creating a new domain on Linux, your Weblogic gets stuck at the following message? Try passing the option to the JVM!

Did it ever happen to you that while you're scp'ing a huge file the connection drops and you have to start all over again? There are big chances that you know I'm talking...

Nowadays virtual environment are very common, thus a hot increase of an existing drive into a virtual machine is a very common operation (roughly equivalent to a LUN expansion in SAN). When you...

Here’s the procedure for adding Oracle 12c DBMS as SMF service in Solaris 11.1, based on this guide. The version provided here is slightly modified for the sake of simplicity as It needs...

Some time ago I’ve built some code to declare Finite State Machines in Java in an annotated fashion so you wouldn’t have to bother yourself with state handling. Since it turned out that...

After putting your precious data into your preferred database (Oracle or MySQL if you’re here) your next worry should be how to back them up. Here Bacula comes to help as a valid...

While executing proguard (via maven2) on MacOSX Snow Leopard, I’ve got the following error: [proguard] Error: Can't read [/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/rt.jar] (No such file or directory) Similarly, you can also get the following error: [proguard]...

Lately I wanted to bring the advantages of ZFS (on Solaris 11 Express) to a Linux box using iSCSI. After following the Oracle guide, I’ve noticed an unexpected behaviour when discovering the iSCSI...

CadSoft’s Eagle (a well known CAD tool for designing PCBs) is not compatible as-is with Linux 64 bit. In my case, after a fresh Fedora 14 install, I was getting this error: #...

Event is a little library built on top of boost::signal and boost::mpl that allows the user to declare in a simple way an object that can emit events and allow connection of (type-safe)...

Some time ago I had a need to display some vectorial drawings on the web so I've found out that SVG is decently supported by modern browsers (I won’t say anything about Internet...

Using GNU Octave is easy to plot Bode and Nyquist diagrams, as follows:

I enjoy Bacula for automated home backups on DLT and DDS tape drives. Being used at home there’s no – obviously – big-dollar-company-manager to ask for an autoloader; and when the time of...

On CentOS 5 (and RedHat EL as well), you can encounter the following behaviour when configuring an nrpe plugin with sudo: [andrea@feyd ~]$ /usr/lib/nagios/plugins/checknrpe -H 1.2.3.4 -c checkmd_raid NRPE: Unable to read output...

Mount a samba share on the fly without having it mounted statically at boot via the file can bring you the advantage of a painless boot in case of unavailability of the samba...

Recently I’ve been in an awkward situation with ssh and X11 forwarding, where ssh using the classic or option wasn’t working (DISPLAY was not set): [andrea@duncan ~]$ ssh -Y root@thufir root@thufir's password: Last...

?- 1 + 2 = 3. fail.

Do you think you can get a fast cheap SATA mass storage at home with Solaris 10 and ZFS just plugging a cheap si3124 controller? Not so easily: on Solaris 10 you will...

On platforms without (MacOSX, Solaris), you can emulate it using as follows (note the upper bound and the lower bound): For example: alia:~ andrea$ echo '[1+pd5>aq]sa0 1-lax' | dc 0 1 2 3...

Sometimes I code something, which might eventually be published here; as I did so far for the followings: - Sun Mar 26 12:45:09 CEST 2006, NNet, a multilayered metaprogrammed c++ neural network. Network...

After years of heroic resistance my site finally became a blog.