IntelliJ IDEA key bindings conflict with Gnome’s window manager. In IDEA, I can type CTRL-B to jump to a symbol definition. Normally, I’d type CTRL-ALT-LEFTARROW to navigate back to where I had come from. Gnome’s MetaCity intercepts that key mapping before IDEA sees it, and tries to move my desktop to the left. There are several other Gnome/Metacity key bindings that conflict with IntelliJ IDEA. Rather than remap the keys in Gnome, I found that on Fedora, I could add the Windows key to the mix, and Gnome would ignore it, and pass it along to IDEA. This means that I can type CTRL-ALT-WINDOWS-LEFTARROW to navigate backward, and so forth.

Unfortunately, this doesn’t work in RHEL 5 and CentOS 5. The solution is to Go to the Gnome menu bar and select System > Preferences > Keyboard (not Keyboard Shortcuts). Then select the “Layout Options” tab, and expand the “Alt/Win key behavior”. Then I select “Super is mapped to the Win-keys”.

Every time I log in after that, Gnome tells me that my X keyboard settings conflict with my Gnome Keyboard settings, and it asks which I want to use. Selecting the Gnome settings is what I want.

Bandwidth limiting downloads with ‘curl’ or ‘wget’

When downloading a large file, it’s nice to be polite to others on the network, so I use the --limit-rate option for curl and wget:

• curl -O --limit-rate 20k http://server.com/linux.iso
• wget --limit-rate=20k http://server.com/linux.iso

GDB TUI (text user interface)

After starting gdb, it’s possible to switch to its text user interface with CTRL-X, CTRL-A. Typing it a second time exits TUI mode.

Vim C++ Auto completion with ctags

I appreciate full blown IDEs in Linux, but I like the quick start up time of vim. Until recently though, I didn’t have C++ auto completion (also known as vim omni completion).

This got me up and running, and was a great resource: http://vim.wikia.com/wiki/C%2B%2Bcodecompletion

This would have been useful if I was a new comer to vim and ctags: http://www.justlinux.com/nhf/Programming/IntroductiontoC_Programming.html

xdg-open, gnome-open, start, cygstart

How to easily open files and URLs from the command line http://www.dwheeler.com/essays/open-files-urls.html

• Linux: xdg-open filename_or_URL
• Linux: gnome-open filename_or_URL
• Mac: open filename_or_URL
• Windows: cmd /c start filename_or_URL
• Cygwin: cygstart filename_or_URL

Nomachine NX and ALT-TAB

I use the Nomachine NX client from time to time to get a remote-desktop like connection to a remote Linux machine. It’s faster than VNC, but it suffers from not forwarding all of my keyboard shortcuts to the remote end of the connection.

Usually, I start the nxlcient from within a Gnome login session. Gnome happily grabs ALT-TAB before the NX client gets to see it. That’s not what I want. To work around this limitation, I log into a virtual terminal, and start X manually as follows:

Type CTRL-ALT-F2 Login Run: startx -- :1 gnome-terminal

From the gnome-terminal, run: nxclient

And then I connect to the remote machine in full screen mode. There’s no local window manager to interfere with my keyboard shortcuts.

Remote desktop and dual screens

I’ve been using Remote Desktop to connect to Windows XP, Vista and 7 machines. Until Windows 7, there was no way for a local computer having dual monitors to connect and have the remote end display across both monitors.

So I used linux’s ‘rdesktop’ program to do it:

rdesktop -0 -a16 -f -rdisk:CLIENT=/home/jared/Desktop -r sound remote.host.com

I notice that in Windows 7, there are some new options in the Remote Desktop client (mstsc.exe): /multimon and /span. Or run mstsc /? to list all possible options.

Editing windows registry files on Linux

Use Gedit: gedit --encoding=UTF-16LE myfile.reg

Gvim: LANG=UTF-16LE gvim myfile.reg

If already in gvim: :e! ++enc=utf-16le or :e ++enc=utf-16le myfile.reg

Convert, edit, convert:

iconv -f UTF-16LE -t utf-8 myfile.reg > myfile.reg.utf8

Edit myfile.reg.utf8, then convert it back

iconv -f utf-8 -t UTF-16LE myfile.reg.utf8 > myfile.reg

How Firefox opens files and mime types

I needed to give Firefox some extra help knowing how to open a custom file type with a custom application. Here’s some helpful information.

https://developer.mozilla.org/en/HowMozilladeterminesMIMETypes

Firefox uses mime.types on Linux, as well as other things. I helped Firefox by the mime type to the link in the generated HTML file. Either one of the following seems to work:

• <a href=”file:subdir/file1.cst” type=”application/octet-stream”> open file </a>
• <a href=”file:subdir/file1.cst” type=”application/x-extension-cst”> open file </a>

I organize my photos by date an a directory structure such as “2010/2010.01.01 New Years Day”. The “2010″ directory contains several sub directories. Each sub directory consists of a date and a description. If, for some reason, I import photos into f-spot that I don’t want in its database, I know what directory the photos pertain to. Unfortunately, F-spot doesn’t allow me to remove photos from its catalog by filename or file path. That’s okay though, because it stores its database using sqlite.

I figured this out by running lsof -p pid-of-f-spot, and noticed a file descriptor opened to “/home/jared/.config/f-spot/photos.db”. Then I ran file ~/.config/f-spot/photos.db and it helpfully told me that it is a “SQLite 3.x database”.

After a bit of google research, I figured out I could install a SQLite manager on my Fedora system: yum install -y sqliteman, followed by running sqliteman ~/.config/f-spot/photos.db. I was expecting to see a command-line client, but to my surprise, I found a pleasant graphical interface. It was simple to browse the table schema and to run queries to update and morph the f-spot photo database. Note: I’d recommend making a backup copy of the database before altering it.

F-spot may not be everything I want it to be, but I managed to work past its limitations due to the fact that it used a well known, open data storage format.

On the new system, I noticed that procmail didn’t seem to be working, and neither did Dovecot. Nor could apache serve up my files. This had all been working on my previous Fedora system, which was running SELinux, as was my new system. What had happened?

I hadn’t told rsync to bring across the SELinux file contexts, which are stored in extended attributes. Here is the rsync option I should have used:

-X, --xattrs

I could have used ‘tar’ to move my home directory as well. In that case, I would have needed one of the following options: --selinux or --xattrs

I resolved my SELinux issues using the excellent SETroubleShoot, which explained what commands to run to restore the proper SELinux contexts on various files.

SELinux requires time to tune, and I use it because it enhances the security of my linux system, which serves up content over HTTP (Apache), IMAP (dovecot) and CIFS (Samba).

Now I’ve got a working guest OS inside of KVM, and I like it. The guest OS feels snappy and responsive.

Update: KVM and the accompanying tools aren’t as mature as VirtualBox or VMWare. E.g. I didn’t see how to get my USB flash drive to be recognized by a KVM guest OS. At one point, I tried to use VirtualBox at the same time as KVM. VirtualBox told me I needed to disable the KVM kernel module before using VirtualBox.

Fedora 11 useful resources:

• Release Notes
• Common Bugs, with workarounds.
• Fedora Guide, explaining how to configure a Fedora system.

Pre-install:

• cp -a /etc /home/backup/etc
• cp -a /root /home/backup/etc
• backup /home
• booted the LiveCD to make sure it would detect my hardware and run

Install

• I decided to preserve my partition layout, which isn't the default option upon fresh install
• Didn't delete my /home partition.
• Reformatted all other partitions, with "/" as ext4

Post-install:

• Had to enable eth0 in NetworkManager, and make "enabled" the default.
• yum install -y meld nautilus-actions nautilus-open-terminal vim-X11 zsh screen mc rdesktop
• meld /home/backup/etc /etc
  • Restored /etc/ssh settings
  • Restored /etc/cups printer settings
  • Checked /etc/fstab differences
• Installed NX Server

Pleasurable:

• Bootup is very pleasant, and seems faster. 30 seconds boot. 17 seconds login. 14 second shutdown. This is on an AMD Athlon 2400 Mhz Sempron with an ATI video card.
• Artwork is top notch (backgrounds on login screen and default wallpaper)

Pain points:

• Unavailable extensions for Thunderbird 3.0 -- Enigmail
• Unavailable extensions for Firefox 3.5 -- Aardvark -- QuickProxy
• Computer locked up every few hours until I added nomodeset to my kernel settings in /etc/grub.conf.

• cp /usr/share/applications/screensavers/personal-slideshow.desktop ~/.local/share/applications/my-slideshow.desktop
• gedit ~/.local/share/applications/my-slideshow.desktop

[Desktop Entry]
Encoding=UTF-8
Name=Custom Photos
Exec=/usr/libexec/gnome-screensaver/slideshow --location=/home/images/Photos
TryExec=/usr/libexec/gnome-screensaver/slideshow
StartupNotify=false
Terminal=false
Type=Application
Categories=GNOME;Screensaver;
OnlyShowIn=GNOME;


Go into the screensaver preferences (System -> Preferences -> Screensaver), and select "Custom Photos". There's no way to customize the duration to display each photo, but at least I don't have to settle for Gnome's default location.

The other day, a co-worker handed me an OpenSolaris 11 Live CD. I booted it, expecting to be underwhelmed like I was with the Solaris 10 JavaDesktop. I was pleasantly surprised, however. Sun’s “Nimbus” GNOME theme knocks the socks off of the boring Fedora window manager themes. The experience felt like I was running Linux. It was responsive, supported my newer hardware, and the system was built with GNU utilities on the command line so I get my favourite options to ‘ls’, ‘grep’, etc. It supported my NVidia card out-of-the box, and had Compiz eye-candy as an option. The only thing I missed (in my superficial test) was the familiar ‘yum’ and ‘rpm’ for package management. I suspect that if I used it from day to day, I’d find other things I miss. Does OpenSolaris support encrypted file systems? Does it have as much optional software as I can get with Fedora Extras?

I’ll keep my eye on OpenSolaris a little more closely in the future.

* Boot into the hardware BIOS setup
* Got to Security -> System Security
* Enable both types of virtualization (VTx and VTd)
* Save settings, and power-cycle the machine.

I’m running Linux, Fedora 9, and using KVM, so I run the following:

modprobe kvm-intel

Loading that module will fail if hardware virtualization isn’t enabled.

* Booted with the Fedora 9 install CD into “rescue mode”
* Ran the following commands once I had a shell:

mount –bind /dev /mnt/sysimage/dev
mount –bind /sys /mnt/sysimage/sys
chroot /mnt/sysimage
mv /boot/initrd-2.6.25…i686.img /boot/initrd-2.6.25…i686.img.orig
mkinitrd /boot/initrd-2.6.25…i686.img 2.6.25…i686

* Then I ran ‘grub’, and typed the following:

root (hd0,0)
setup (hd0)
quit

* Ejected the install CD, and rebooted. Once booted, I noticed that my network cards weren’t set up quite right. My new network card was listed as “eth2″ in system-config-network, and I didn’t actually have cards for the listed “eth0″ and “eth1″ interfaces anymore. I didn’t know what file to change to get my new card listed as “eth0″, so I ran the following command to find out what files I might need to edit:

find /etc -type f -print0 | xargs -0 grep “eth[01]“

That command listed the following files, among others:

* /etc/udev/rules.d/70-persistent-net.rules
* /etc/vmware/locations

I edited /etc/udev/rules.d/70-persistent-net.rules and ripped out the assignments for my old NIC interfaces, and set the new one to be “eth0″, then rebooted and used `system-config-network` to set up my network.

When I ran my VMware guest, VMware Server gave me an error message about not being able to use bridged mode for the selected interface. With my old computer, VMware had used eth1 for bridged networking, and I didn’t have an “eth1″ interface anymore. I edited /etc/vmware/locations and changed “eth1″ to “eth0″, and restarted vmware. This time, bridged mode worked correctly.

Installing this package sets up the xguest user to be used as a temporary account to switch to or as a kiosk user account. The account is disabled unless SELinux is in enforcing mode. The user is only allowed to log in via gdm [or the fast-user-swiching applet]. The home and temporary directories of the user will be polyinstantiated and mounted on tmpfs.

Here’s how to install it:

yum install xguest

I hit a brick wall when I first tried it. I thought my machine was in SELinux Enforcing mode, when it wasn’t — it was in Permissive mode. I fixed it using system-config-selinux.

It’s possible to change what the xguest user can do using system-config-selinux. I’ve attached a screenshot showing what capabilities can be granted or revoked.