CrystalLabs — Davor Ocelic's Blog

Tech blog about Unix, GNU/Linux, programming, systems administration, DevOps, cloud, Free Software, Open Source, privacy, security, and ethics.

Articles by Last Update Date

Computer cartography. OpenStreetMap (OSM), Mapnik, Tirex. WMS, TMS, WMTS, KML, Slippy. Leaflet, OpenLayers, QGIS, Marble. iD, JOSM, Vespucci, Go Map!!. GPS, GPX.

Git. Multiple repository origins. Projects mirrored at different hosting platforms.

Computer cartography. OpenStreetMap (OSM), MapProxy. WMS, WMTS, Slippy, TMS, KML. Custom tile proxy and cache.

Computer cartography. OpenStreetMap (OSM), Leaflet, Slippy. Custom map viewer.

History. CTSS, BTS, Multics, ITS, Unix, C, BSD, Unix wars, Motif, CDE, GNU, Linux.

Making automated replacements in text files. Shows Perl, regular expressions, Git, diff, and other Unix shell commands. Quiz.

Original Unix, BSD, GNU, Linux. Books, papers, videos, and similar materials.

GNU/Linux and Debian GNU documentation. Where is it, how to access it. Man, info, tldr, /usr/share/doc/, TAB, IRC, RFCs, HOWTOs, FAQs, kernel docs. Quiz.

Your own blog like crystallabs.io. Hugo framework, minima-crystallabs theme. Clone and run. Quick success.

Physical one-way data link. 100Mbps ethernet + UDP/IP. File transfer with ncat or socat and tar.

Docker. Images and Containers. Description and use.

Intro to Unix commands. List of most important ones. Basic info everyone should know. Quiz.

Unix, GNU, Linux and general IT resources. Becoming an old-school pro.

Three-point VPN Gateway. WireGuard, IPTables/NFTables, DNS, dnsmasq. VPN server and Internet gateway on different machines.

OpenAFS – global, distributed, network filesystem from CMU. Practical installation. “Where ever you go, there you are”.

Standard input, output, error. Stdin, stdout, stderr. File descriptors, fd. Pipes, redirection.

Unix File Descriptors
Aug 07, 2023

File descriptor, fd. Quiz.

Practical introduction to OpenLDAP. Slapd, slapd.conf, olc, slapd.d, cn=config, nsswitch.

Rapid-fire Unix and Linux tips. Basic usage everyone should know. Desktop, shell, terminal, copy-paste, key shortcuts. You’d be surprised.

Linux Virtual Consoles
Aug 06, 2023

Linux, text mode, virtual console, terminal, tty, ctrl+alt+f keys.

Unix, Linux password reset. Bootloader, grub, init, mount, passwd, reboot, sysrq. Funny story.

Practical introduction to MIT Kerberos 5. KDC, kadmin.local, kadmin, PKINIT, exhaustive troubleshooting recipes.

ZeroMQ async messaging. Can run brokerless. Runs on top of ITC, IPC, PGM, TCP, TIPC, UDP, or VMCI. BSD sockets-like API. REQ-REP, PUB-SUB, and PUSH-PULL pattern.

About
Jul 23, 2023

Site purpose. Content organization. Brief history.

Introduction to file versioning. History of version control tools SCCS, RCS, CVS, Subversion, BitKeeper, and Git. Funny story.

SGI IRIX 6.5 Tips
Oct 10, 2005

SGI IRIX 6.5. Misc user tips.

Lt1. Linux, GNU, diskless, single floppy, 1.44MB, 2MB flash RAM, ramdisk, rescue disk.