This week: technology links and a chart with sunlight hours.

Technology

• grep tricks: grep files recursively, show only filenames where matching string was/wasn’t found.
• Did you know that:
  • $ less <directory> — shows directory listing
  • $ less <archive.zip> — shows archive content
• Teacher’s rumblings “Kids can’t use computers“. Agree to a T.
• Going back to iPhone [from Android]. Again having pretty much the same thoughts.
• Reddit: Lessons Learned From Mistakes Made Scaling To 1 Billion Pageviews A Month
• Start a Web Search in a GUI Browser from the Command Line on Mac OS X
• Screen recording to an animated GIF on Mac OS X
• How to know from a child process that its parent exited:
  • a pipe between parent and a child, child gets SIGPIPE when parent exits
  • if a child has not detached, PPID becomes 1 when parent exits
  • Linux-specific: a child can ask kernel to deliver a signal when parent dies by specifying option PR_SET_PDEATHSIG in prctl() syscall
• Two talks from YAC which I liked:
  • Small service administration
  • Fault-tolerance and load balancing
• rpmdb locking issues, notorious on RHEL4/5, manifest as a hanging rpm command. To see active locks:

  # cd /var/lib/rpm; /usr/lib/rpm/rpmdb_stat -CA
  

  Normally there should be no locks, given no rpm command is running. In case there are stale locks, just remove __db.00* files.

Other

• Learning second language later in life brings brain change
• Evolution: educating pupils (in Russian)
• Wonderful photos by National Geographic

Sunlight in Europe and the USA in hours per year

This week: technology links and Stephen Fry’s open letter.

Technology

• Cloud server showdown: Amazon AWS EC2 vs Linode vs DigitalOcean. AWS performance sucks, Linode winner.
• Pull mode in orchestration’s rising star, Ansible. Check also out the web interface — AnsibleWorks AWX
• Learning from other disciplines, nice quote:

  I’ve seen several college of engineering departments that have a sign that says the equivalent of, “If you cheat in engineering classes, you will kill people later”. We don’t have that mindset yet with IT, but I think we should because eventually, we’ll be responsible for infrastructure that will kill people if we get it wrong.

• knockd — a port-knock server. It listens to all traffic on an ethernet (or PPP) interface, looking for special “knock” sequences of port-hits. A client makes these port-hits by sending a TCP (or UDP) packet to a port on the server. When the server detects a specific sequence of port-hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access.
• Here’s the example of why LISA conferences rock: 2007 paper On Designing and - Deploying Internet-Scale Services. Must read for sysadmins.
• How to automatically setup and keep ssh tunnel up with autossh, available from macports

Social

Steven Fry, one of my all-time favourite actors and activists, wrote an open letter petitioning for moving Winter Olimpics 2014 from Russia to elsewhere, because of wilful LGBT community oppressions. On a related note, sexual orientation forms during prenatal period, influenced by hormone levels, and is therefore inborn feature. Read about it in Russian.

This week: technology links and some English titbits.

Technology

• Know Thy Complexities! Big-O Cheat Sheet and its Russian translation
• The US is home to one third of the world’s data—here’s who’s storing it
• gawk/awk implementation of crc32 (compatible with the POSIX cksum command)
• Microsoft: Pure Dumb (Bad) Luck: “Where does this leave Microsoft? Not so great, I’m afraid. When even WindowsITPro.com is questioning your trust, you’re in bad shape.”
• How to imitate TCP Wrapper with iptables
• SysAdmins – In Their Own Words

English

• Don’t say good bye; just ghost:

  Ghosting—aka the Irish goodbye, the French exit, and any number of other vaguely ethnophobic terms—refers to leaving a social gathering without saying your farewells. One moment you’re at the bar, or the house party, or the Sunday morning wedding brunch. The next moment you’re gone.

• The war of the words. How Republicans and Democrats use language:

  Republicans are also better, Democrats fear, at agreeing on a message and sticking to it. Frank Luntz, a Republican consultant, once said: “There’s a simple rule. You say it again, and you say it again, and you say it again, and you say it again, and you say it again, and then again and again and again and again, and about the time that you’re absolutely sick of saying it is about the time that your target audience has heard it for the first time.”

This week: technology links, algorithm courses, bootstrap goodies, and Ukrainian IT.

Technology

• Configure Tor on Mac OS X to Browse the Web Anonymously & Access Blocked Websites
• ifconfig.me returns your external IP address, and loads of other info:

  $ curl ifconfig.me
  204.232.175.78
  $ curl ifconfig.me/host
  acme.com
  $ curl ifconfig.me/all.xml
  ...
  $ curl ifconfig.me/all.json
  

• The trouble with OpenStack
• Very apt ITIL vs DevOps comparison table

Education

My most favourite coursera course Algorithms by Kevin Wayne and Robert Sedgewick of Princeton is coming back with new session this autumn; my passionate recommendation to take it if you’re doing any kind of programming, either to improve your skills or just get a lot of fun:

• Part I, starts on 23 August
• Part II, starts on 1 November

Bootstrap-related

• Links to theme generators, fonts, editors, pallets, and add-ons
• Links to form builders, icons, fonts, and plugins

IT in Ukraine (in Russian)

• DOU specialty report on IT salaries in Ukraine
• Ukrainian IT specialist infographics

Miscellaneous

Petit Fille, liked choreography a lot:

This week: technology links and AmE vs BrE talk.

Technology

• Three ways how to get Apache to automatically insert the Google Analytics script into every page on the fly.
• SSL: Intercepted today, decrypted tomorrow — recently leaked documents appear to reveal that the NSA logs very high volumes of internet traffic and retains captured encrypted communication for later cryptanalysis. The reason […] is that if the SSL private key to the encrypted traffic later becomes available — perhaps through court order, social engineering, successful attack against the website, or through cryptanalysis — all of the affected site’s historical traffic may then be decrypted at once.
• First 5 Minutes Troubleshooting A Server, great post, Russian translation is here.
• Swagger is a specification and complete framework implementation for describing, producing, consuming, and visualizing RESTful web services.

English

Shop Talk with Lynne Murphy about American English versus British English.