random linux notes 2012-04

Perm URL with updates: http://xahlee.org/linux/linux_notes_2012-04.html

haven't done serious unix sys admin for about a decade. (serious = sys admin in server farm.)

been playing with ubuntu for past days. Oh, su and chmod and w id whoami ps top fg bg nice mount passwd etc fdsk shit. The horrors of unix all came back.

installed Oracle VM Virtualbox with guest OS Ubuntu and Fedora.

Actually got to know Virtualbox for real, for first time.

VirtualBox is so great. You can run several linux distros, and you can fuck unix. When they finally can't take anymore, kill! Start anew! Life's good.

Ubuntu vs Fedora vs Linux Mint

Fedora is from Red Hat. Linus uses it. Ubuntu is a distro specialized for dummies, but in many ways it's much smooth, but is still linux that you can change anything if you know what u doing. Fedora doesn't seem to be known for any specialized take. The top 3 most pop linux distro are: Linux Mint, Ubuntu, Fedora. (the main thrust of Linux Mint appears to bundling all proprietary software sans FOSS ado. (yay!))

ubuntu linux for dummies

Oracle VM VirtualBox

VirtualBox is really fantastic. Because you can use it like a sandbox. Try multiple OSes. Also, you can try unix things that normally you wouldn't, because if screwed up, you can just discard it. You can also use it to visit malware sites, etc. Great for experimentation and learning.

if you haven't already, it's worth a try, even if it meant spending a few days to get familiar with it.

• copy/paste between guest/host needs to have “guest additions” installed. “guest additions” is to be installed in the guest OS. While guest OS is running, use menu 〖Devices▸install Guest Additions…〗. When done, restart guest OS.

• Shared folder feature must have guest additions installed. When installed, it's auto-mounted in 〔/media/〕.

The VirtualBox manual is quite handy. It's in the menu 〖Help〗.

Which Unity Are You Running?

Ubuntu 11.10 runs the GUI called Unity. It shows a launch bar on the left.

Note: there's “Unity 3D” and “Unity 2D”. The “Unity 3D” is often just written as Unity. They look almost identical, but are entirely different implementations. The 2D one is for systems with weak graphics card. (i.e. when you run from VirtualBox) Many discussions online about configuring Unity is about Unity 3D. So, beware. Reference: askubuntu.com am i using unity or unity 2d, askubuntu.com How do I configure Unity 2D?

Ubuntu Unity 3D Ubuntu Unity 2D
Unity 3D (left) and Unity 3D (right)

How to Tell If You Are Using Unity or Unity 2D

press 【Ctrl+Alt+t】 opens a new terminal, then type echo $DESKTOP_SESSION it'll print “ubuntu-2d” if you are on 2d, else it's just “ubuntu”.

Or, type pgrep -l unity. If the result contains “unity-2d-launch”, then you are on 2d.

Ubuntu GUI Issues

• the Win key pops up the Ubuntu launch bar.

• to re-arrange the app icon in launcher bar, click and hold first.

• To show menu in gnome-terminal, press Alt key.

• Middle click in general brings up up context menu. Also, Menu key works.

• Right click on window title bar send the window to back.

• You can set single click to open folder. Just go to the menu 〖Edit▸Prefernces〗 while in a folder.

is ubuntu software center a interface on top of apt-get/dpkg?


• 【Ctrl+Alt+t】 opens a new terminal.

To see all keyboard shortcuts, goto “System Settings”, Keyboard, Shortcuts tab.

GUI Tool Command Names

• The folder viewer (file manager)'s command line name is nautilus. Nautilus (file manager)

• The default terminal is GNOME Terminal. The command line name is gnome-terminal.

the launch bar is unity-2d-launcher

the top menu is unity-2d-panel

cpu monitor ⇒ gnome-system-monitor

“Charmap” (unicode character viewer) ⇒ gucharmap

dictionary ⇒ gnome-dictionary


“WenQuanYi Zen Hei” (文泉驛) WenQuanYi is for Chinese. This font is included in most linuxes. (➲ Chinese Character Etymology and Script Styles)

Ubuntu Unix Issues

• use ps -ef. ps aux also supported. See Wikipedia on ps about the abomination.

in Ubuntu, why su doesn't work, but sudo su works?

because Ubuntu by default doesn't setup password for root. (thanks to Thomas Yao, Manuel Lara, Jeff Weiss)

ubuntu. sudo cd ‹restricted dir› got error of “cd command not found”. I can sudo bash first, then cd. WHAT'S better way?

Answer: Source askubuntu.com Short story: just sudo -i or sudo bash to start a new session. As long as you need to do stuff on that dir. When done, exit that rooted shell session.

what's the meaning of ls output colors?

it's fairly complex. Better just ignore. You can man dircolors and dircolors -p.

on Ubuntu, where are the info files? info -w returns nothing.

It's at the env var $INFOPATH. Or, default to 〔/user/share/info〕.

Rant & Opinions

Ubuntu is much more smooth and Fedora. Though, it's nothing compared to Windows. Mac is best as far as user experience goes.

Microsoft terminology Won: GUI is Shell

so, these days, GNOME, KDE, Unity, adopted Windows term of GUI as “shell”. e.g. you say GNOME Shell, instead of Gnome GUI or Gnome Desktop Environment.

lol. I guess Windows terminology won. (Windows shell)

a decade ago, this would be unthinkable. The fucking tech geekers will say you are a idiot, and shell means shell. That is, unix shell, console, terminal emulator, the shebang stuff.


lies. fud from unix ran rampant. quote from info chroot:

   (1) However, some systems (e.g., FreeBSD) can be configured to allow
certain regular users to use the `chroot' system call, and hence to run
this program.  Also, on Cygwin, anyone can run the `chroot' command,
because the underlying function is non-privileged due to lack of
support in MS-Windows.

list installed software: dpkg -l, dpkg --get-selections

• find out chinese fonts that are bundled on ubuntu.

Ion (window manager)

On April 28, 2007, Valkonen warned the Arch Linux maintainers of possible legal action because the (unofficial) Arch User Repository contained scripts to install Ion3 with patches he did not approve of.[5] Later on he did the same with the pkgsrc maintainer of the NetBSD project[6] and the ports maintainer of the FreeBSD project.[7] As of December 12, 2007,[8] the development branch of Ion, along with other software by Valkonen, was pulled[9] from the FreeBSD ports tree, after the author filed a complaint about outdated development releases still being available. Any version of Ion may still be installed from source code on any Unix system with proper libraries and dependencies.

Valkonen has implied in several mailing lists that he has become completely disillusioned with, if not openly hostile toward, the free software community in general. He plans to switch to developing strictly closed-source software for the Windows platform in the future,[10] presumably following the stable release of the Ion3 branch. Subsequently the author has indeed given up on *nix and started using Windows instead.[11]

lol. open sourcer or the fsf fuckheads, what can one say.

the fighting of these scumbags is everywhere. On one hand, cries of morality and ethics and want Bill Gates and Steve Jobs dead, on the other there's Ubuntu Unity vs Gnome war (2011-03), KDE vs Gnome war (1999), several splinter groups of BSD ((FreeBSD, NetBSD, OpenBSD) 1990s, (or DragonFly) 2000s), BSD vs Linux (1999), Firefox logo vs Debian war (2004) (then Iceweasel vs Icecat split, 2007) (which begets Iceweasel fuck) …, Python licensing issue with GPL war (1990s), FSF vs Open Source war (1999), Debian definition of Free vs FSF free war (2005), Linus vs GPL3 war (Tivoization), war, war, factions, and splinter groups, and war, severe enough that each wants to gouge other's eyes out.

O, and fuck Richard Stallman who refuses to cooperate or use with anything except everybody to become his GNU underling.


• is there a way to use apt-get or dpkg to list available packages? and get a short description?

Ubuntu. When running firefox or emacs from terminal, i get errors about some theme engine pixmap. WTF are those?

xah@xah-VirtualBox:~$ firefox &
[1] 2365
xah@xah-VirtualBox:~$ OpenGL Warning: Failed to connect to host. Make sure 3D acceleration is enabled for this VM.
failed to create drawable

(firefox:2365): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",

xah@xah-VirtualBox:~$ emacs &
[2] 2448
(emacs:2448): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",

Answer: it's a buge. See: Source askubuntu.com. (Thanks to Chris Woods)

Solution: run sudo apt-get install gtk2-engines-pixbuf.

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