Random code https://vleo.net https://vleo.net/blog/macos/ https://vleo.net/blog/macos/ Mon, 26 Oct 2020 14:37:34 GMT Lately I was installing the embedded ARM toolchain to compile some STM32 code, and I ran into this beautiful error: If you are a macOS user it's very probable that you have already seen this message, and most likely you already know the workaround (which is right-click on the executable... https://vleo.net/blog/macos-pl-232/ https://vleo.net/blog/macos-pl-232/ Tue, 11 Aug 2020 16:18:00 GMT 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 experience with these was far from optimal. Then, I finally I found my peace buying this one:... https://vleo.net/blog/macos-java9-libfreetype/ https://vleo.net/blog/macos-java9-libfreetype/ Thu, 11 Jul 2019 09:37:06 GMT 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 STM32CubeMX on my (freshly formatted) laptop and I incurred in this friendly error: Andreas-MacBook-Pro:~ a.leofreddi$ ~/Downloads/en.STM32CubeMXv5-0-1/SetupSTM32CubeMX-5.0.1.app/Contents/MacOs/SetupSTM32CubeMX-501macos chdir... https://vleo.net/blog/aws-cognito-user-report/ https://vleo.net/blog/aws-cognito-user-report/ Thu, 20 Jun 2019 14:00:00 GMT 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 is lacking some basic user management functionalities. Things like deleting a user by username or send back... https://vleo.net/blog/power-generator-auto-start-mod/ https://vleo.net/blog/power-generator-auto-start-mod/ Sat, 11 May 2019 18:08:53 GMT DISCLAIMER Carbon monixide is very poisonous and can kill quickly! Under no circumstances I will be held responsible or liable in any way for any claims, damages, losses, death, expenses, costs or liabilities whatsoever! Leaving in the countryside has many good sides, the power grid connection not being one of... https://vleo.net/blog/manage-multiple-jdk-versions-on-macos/ https://vleo.net/blog/manage-multiple-jdk-versions-on-macos/ Thu, 04 Apr 2019 14:22:58 GMT 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: 100% (24/24), done. remote: Compressing objects: 100% (19/19), done. remote: Total 24 (delta 12), reused 10 (delta... https://vleo.net/blog/perl-fails-to-compile-xs-modules-on-macos-mojave/ https://vleo.net/blog/perl-fails-to-compile-xs-modules-on-macos-mojave/ Thu, 04 Apr 2019 11:05:12 GMT 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 CryptX.c cc -c -DLTMDESC -Isrc/ltc/headers -Isrc/ltm -g -pipe -fno-common -DPERLDARWIN -fno-strict-aliasing -fstack-protector -Os -DVERSION=\"0.063\" -DXS_VERSION=\"0.063\" "-I/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE" CryptX.c... https://vleo.net/blog/using-slf4j-from-c-jni/ https://vleo.net/blog/using-slf4j-from-c-jni/ Wed, 14 Nov 2018 20:00:38 GMT 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 say for example you have the following Java class: import lombok.extern.slf4j.Slf4j; @Slf4j public class NativeGlue { public... https://vleo.net/blog/internet-is-a-safe-place/ https://vleo.net/blog/internet-is-a-safe-place/ Wed, 14 Nov 2018 19:19:55 GMT 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 failed login attempts since the last successful login. [a.leofreddi@XXX ~]$ https://vleo.net/blog/scanner-with-mono-document-feeder-how-to-scan-double-sided-documents-2/ https://vleo.net/blog/scanner-with-mono-document-feeder-how-to-scan-double-sided-documents-2/ Tue, 05 Dec 2017 16:34:56 GMT I'm a happy owner of a Brother DCP-9020CDW which has a nice document-feeder feature, allowing you to automatically scan multi page documents (and perfectly integrated with macOSX). Unfortunately the feeder there is able only to scan a single side of the documents, so when dealing with double-sided documents I usually... https://vleo.net/blog/untitled-2/ https://vleo.net/blog/untitled-2/ Tue, 04 Jul 2017 19:45:29 GMT 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: gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sOutputFile=output.pdf input.pdf To get installed, one can just brew it: https://vleo.net/blog/yubico-yubikey-centos-rhel-7-and-ssh/ https://vleo.net/blog/yubico-yubikey-centos-rhel-7-and-ssh/ Sat, 29 Oct 2016 14:01:02 GMT 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 procedure to setup yubikey authentication for CentOS/RHEL 7: 1. Enable the EPEL repository: 2. Install the pamyubico... https://vleo.net/blog/timel-a-new-streaming-api/ https://vleo.net/blog/timel-a-new-streaming-api/ Fri, 08 Jan 2016 10:36:00 GMT 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 of data with a constant memory footprint! You can find more on TimEL’s homepage or on its... https://vleo.net/blog/jetty-on-rhel-7centos-7/ https://vleo.net/blog/jetty-on-rhel-7centos-7/ Sun, 15 Nov 2015 14:16:56 GMT 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 fresh distribution of Jetty tarball. Since Jetty is already packaged in RHEL 7, I’d rather use the... https://vleo.net/blog/cyberz-org-is-now-vleo-org/ https://vleo.net/blog/cyberz-org-is-now-vleo-org/ Sun, 11 Oct 2015 12:44:47 GMT 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 (yes, every now and then still I log back on irc ;) ). So I’ve decided to... https://vleo.net/blog/selinux-how-to-change-default-context-of-a-directory/ https://vleo.net/blog/selinux-how-to-change-default-context-of-a-directory/ Tue, 24 Feb 2015 16:24:29 GMT 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 content). Follows an example: https://vleo.net/blog/weblogic-12c-very-slow-domain-creation/ https://vleo.net/blog/weblogic-12c-very-slow-domain-creation/ Fri, 31 Oct 2014 15:41:02 GMT While creating a new domain on Linux, your Weblogic gets stuck at the following message? Try passing the option to the JVM! https://vleo.net/blog/resuming-an-scp-transfer/ https://vleo.net/blog/resuming-an-scp-transfer/ Fri, 03 Jan 2014 12:43:58 GMT 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 about :) Fear no more! Rsync can be used over ssh and it can resume the copy... https://vleo.net/blog/how-to-expand-a-zfs-device/ https://vleo.net/blog/how-to-expand-a-zfs-device/ Tue, 17 Sep 2013 07:52:41 GMT 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 expand a zpool device, the new size won’t be immediately available to zfs, but you can easily... https://vleo.net/blog/smf-manifest-oracle-12c/ https://vleo.net/blog/smf-manifest-oracle-12c/ Mon, 09 Sep 2013 14:21:32 GMT 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 only the to run (no additional scripts or configuration are required). The procedure should work even with... https://vleo.net/blog/jsm-a-java-state-machine/ https://vleo.net/blog/jsm-a-java-state-machine/ Mon, 17 Sep 2012 20:06:45 GMT 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 the code has been useful in more than a couple occasions, I’ve decided to share it. JSM... https://vleo.net/blog/oracle-and-mysql-bacula-integratio/ https://vleo.net/blog/oracle-and-mysql-bacula-integratio/ Fri, 29 Jun 2012 17:14:40 GMT 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 opensource network enterprise backup system – but how to get it working with your database? In this... https://vleo.net/blog/multi-lun-autoloader-with-vmware-esxi-5-0-with-adaptec-scsi-hba/ https://vleo.net/blog/multi-lun-autoloader-with-vmware-esxi-5-0-with-adaptec-scsi-hba/ Fri, 16 Mar 2012 11:41:35 GMT VMware ESXi 5 is not able to handle multi-lun devices by default, so many SCSI autoloaders are not supported as-is (as HP StorageWorks LTOs), showing only the tape drive or media changer but not both: To have it work in ESXi it’s enough to: 1. Get a multi-LUN aware SCSI... https://vleo.net/blog/proguard-on-macosx/ https://vleo.net/blog/proguard-on-macosx/ Mon, 21 Feb 2011 12:47:03 GMT 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] Error: Can't read [/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/lib/jsse.jar] (No such file or directory) That happens because the Java bundled with MacOSX... https://vleo.net/blog/solaris-11-express-bind-iscsi-to-ip/ https://vleo.net/blog/solaris-11-express-bind-iscsi-to-ip/ Sun, 30 Jan 2011 17:41:04 GMT 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 targets (from a CentOS host): [root@zimbra ~]# iscsiadm -m discovery -t sendtargets -p 192.168.64.10 192.168.64.10:3260,1 iqn.2011-01.org.cyberz:storage:mail 192.168.64.106:3260,1... https://vleo.net/blog/openwrt-on-tp-link-tl-wr743nd/ https://vleo.net/blog/openwrt-on-tp-link-tl-wr743nd/ Sun, 02 Jan 2011 01:19:59 GMT TP-Link TL-WR743ND is the PoE brother of the common TL-WR741ND wireless router which is supported flawlessly by openwrt. Since I’ve got one WR743ND, I wanted to convert it into a useful OpenWRT router but I figured out that, unfortunately, the WR743ND is not supported by OpenWRT (at least officially). Given... https://vleo.net/blog/cadsoft-eagle-and-fedora-linux-x86_64/ https://vleo.net/blog/cadsoft-eagle-and-fedora-linux-x86_64/ Sun, 28 Nov 2010 23:16:58 GMT 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: # sh eagle-lin-5.10.0.run eagle-lin-5.10.0.run: /tmp/eagle-setup.3778/eagle-5.10.0/bin/eagle: /lib/ld-linux.so.2: bad ELF interpreter: No such file or directory To get the thing... https://vleo.net/blog/solaris-10-x64-and-symbios-sym22801/ https://vleo.net/blog/solaris-10-x64-and-symbios-sym22801/ Sat, 24 Jul 2010 20:33:13 GMT Today I’ve discovered that the very common Symbios 22801 (aka Symbios Logic 53c875) SCSI controller is (unexpectedly) failing to be recognized by Solaris 10 on x64 hardware. In fact I was in the middle of the upgrade of my home backup infrastructure from an old DLT 20/40 to a newer... https://vleo.net/blog/i2c-anemometer-cheap-wind-data-logger/ https://vleo.net/blog/i2c-anemometer-cheap-wind-data-logger/ Sat, 19 Jun 2010 19:26:02 GMT Lately I’ve been wondering if a wind-generator could help me lower my electricity bill (since my home server burns continuously some hundred watts per hour) in my town, Ponzano Romano. So I came up to the idea that wind data logging is absolutely a must for any further reasoning about... https://vleo.net/blog/cyberzorgevent-library-typesafe-event-handling-in-c/ https://vleo.net/blog/cyberzorgevent-library-typesafe-event-handling-in-c/ Tue, 25 May 2010 22:22:05 GMT 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) callbacks as event handler to them. Usage is pretty straightforward, as shown in test/hello.cc: #include #include "event.h"... https://vleo.net/blog/svgpan-a-javascript-svg-panzoomdrag-library/ https://vleo.net/blog/svgpan-a-javascript-svg-panzoomdrag-library/ Tue, 08 Dec 2009 19:37:34 GMT 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 Explorer – it’s just unsupported there). The language itself is great, but the interactivity provided by the... https://vleo.net/blog/bode-and-nyquist-diagrams-using-gnu-octave/ https://vleo.net/blog/bode-and-nyquist-diagrams-using-gnu-octave/ Mon, 07 Dec 2009 18:51:36 GMT Using GNU Octave is easy to plot Bode and Nyquist diagrams, as follows: https://vleo.net/blog/bacula-mail-changer-script-aka-poor-mans-autoloader/ https://vleo.net/blog/bacula-mail-changer-script-aka-poor-mans-autoloader/ Mon, 08 Jun 2009 23:16:32 GMT 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 a tape change comes bacula lacks a simple way to request a manual tape change and just... https://vleo.net/blog/some-applications-using-i2c/ https://vleo.net/blog/some-applications-using-i2c/ Mon, 08 Jun 2009 22:49:43 GMT Parallel and serial ports are disappearing from today’s pc making life harder for the people who wants to connect their home-made devices to a pc. Some time ago I was considering USB, but it's really quite complex, so I looked over it. The I2C bus instead is very easy to... https://vleo.net/blog/code-review/ https://vleo.net/blog/code-review/ Wed, 18 Feb 2009 19:34:45 GMT https://vleo.net/blog/nagios-nrpe-and-sudo-nrpe-unable-to-read-output/ https://vleo.net/blog/nagios-nrpe-and-sudo-nrpe-unable-to-read-output/ Sat, 03 Jan 2009 19:21:21 GMT 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 Given that checkmdraid is defined as follows, in nrpe.conf: command[checkmdraid]=sudo /usr/local/bin/nagioscheckmd_raid And given (for completeness) its relative... https://vleo.net/blog/using-samba-with-autofs-on-fedora-9/ https://vleo.net/blog/using-samba-with-autofs-on-fedora-9/ Sun, 07 Sep 2008 15:55:54 GMT 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 server like in the following common scenarios: - laptop: you mount your pc share at home, but... https://vleo.net/blog/delirii-in-bash/ https://vleo.net/blog/delirii-in-bash/ Fri, 18 Apr 2008 13:19:44 GMT https://vleo.net/blog/musicbrainz-not-working-with-amarok-on-fedora-8/ https://vleo.net/blog/musicbrainz-not-working-with-amarok-on-fedora-8/ Sun, 13 Apr 2008 11:14:05 GMT On my Fedora 8 system with Amarok I was trying to fill an mp3’s tag header using MusicBrainz, getting the following error: To make it work, just https://vleo.net/blog/ssh-x11-forwarding-issue/ https://vleo.net/blog/ssh-x11-forwarding-issue/ Sat, 12 Apr 2008 22:38:53 GMT 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 login: Sat Apr 12 23:30:09 2008 from * [root@thufir ~]# echo $DISPLAY [root@thufir ~]# If you are... https://vleo.net/blog/artificial-intelligence/ https://vleo.net/blog/artificial-intelligence/ Mon, 31 Mar 2008 09:28:51 GMT ?- 1 + 2 = 3. fail. https://vleo.net/blog/solaris-si3124-backport-workaround-for-bug-6566207/ https://vleo.net/blog/solaris-si3124-backport-workaround-for-bug-6566207/ Sat, 08 Mar 2008 00:28:31 GMT Do you think you can get a fast cheap SATA mass storage at home with Solaris 10 and ZFS just plugging a cheap si3124 controller? Not so easily: on Solaris 10 you will be afflicted by some boring bug known as bug #6566207 which gets your controller stuck for around... https://vleo.net/blog/seq-equivalent-on-solarismacosx/ https://vleo.net/blog/seq-equivalent-on-solarismacosx/ Wed, 27 Feb 2008 20:19:28 GMT On platforms without (MacOSX, Solaris), you can emulate it using as follows (note the upper bound and the lower bound): For example: alia:~ andrea$ echo '[1+pd5>aq]sa0 1-lax' | dc 0 1 2 3 4 5 alia:~ andrea$ https://vleo.net/blog/projects/ https://vleo.net/blog/projects/ Wed, 27 Feb 2008 19:56:54 GMT 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 topology is determined by compile-time type declaration. - Mon Feb 2 01:31:36 CET 2004, pam_quota, a simple... https://vleo.net/blog/last-of-the-mohicans/ https://vleo.net/blog/last-of-the-mohicans/ Wed, 27 Feb 2008 01:18:04 GMT After years of heroic resistance my site finally became a blog. https://vleo.net/blog/nnet-a-metaprogrammed-c-neural-network/ https://vleo.net/blog/nnet-a-metaprogrammed-c-neural-network/ Sun, 26 Mar 2006 10:45:00 GMT NNet is a (metaprogrammed) neural network. It allows the selection of the network layout (number of layers and activation functions) in a simple way, without runtime costs -- check out the following 2 hidden layers network: typedef NeuralNetwork, Layer, Layer, Layer > > NNet; Sources include a simple SDL example... https://vleo.net/blog/controlling-the-hp-netserver-5133-ls2-lcd/ https://vleo.net/blog/controlling-the-hp-netserver-5133-ls2-lcd/ Sat, 06 Dec 2003 18:15:41 GMT Some time ago I got an old HP NetServer 5/133 LS2 (that I revived with FreeBSD). After giving some progress during the boot process, the front LCD display gets stuck with a useless description when the system is up and running, as shown here: I thought it would be nice...