Sat, 22 Oct 2016
Keywords: Windows capslock escape control caps2esc
On almost all modern keybaords the useless capslock key is right where something useful should be. Initially the control key would have been there. Sometimes the escape key was there and this influenced the design of vi.
The escape key and the control key can actually be combined such that if you press the key on its own then you get and escape, and if you press it with something else you get the control key. Then you need to put this key where the capslock key is now and move the capslock to the escapse key.
On Windows the Interception library can be used to do this. The steps are:
- Download and install the [https://www.microsoft.com/en-us/download/details.aspx?id=11800 Windows Driver Kit] - Set WDK to C:/WinDDK/7600.16385.1 (or wherever it was installed) - git clone https://github.com/oblitum/Interception - run buildit.cmd in the library directory - run buildit.cmd in the samples/caps2esc directory - copy caps2esc/objfre_wxp_x86/i386/caps2esc.exe and library/objfre_wxp_x86/i386/interception.dll into a new directory (I use C:/caps2esc) - add a shortcut to c:/caps2esc/caps2esc.exe to the startup directory
For linux use caps2esc, but this won't work well inside a VM.
Wed, 28 Jan 2015
Keywords: linux debian conntrack
To set up conntrack on debian 6:
# aptitude install conntrack # modprobe nf_conntrack_ipv4 # cat /proc/sys/net/ipv4/netfilter/ip_conntrack_max # cat /proc/net/ip_conntrack # aptitude install iptstate # rehash # iptstate
Sat, 27 Jul 2013
Keywords: rvm ruby 1.9.3 tmuxinator zsh
In order to upgrade tmuxinator I needed to run Ruby 1.9.3. So I installed rvm as follows:
$ bash -s stable < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)
and added the following to my .zshrc:
if [[ -e ~/.rvm/scripts/rvm ]] then . ~/.rvm/scripts/rvm . ~/.rvm/gems/ruby-1.9.3-p448/gems/tmuxinator-0.6.2/completion/tmuxinator.zsh fi
$ rvm install 1.9.3 $ rvm use 1.9.3 --default $ gem install tmuxinator
I also had up change my tmuxinator config files:
$ cd ~/.tmuxinator $ perl -pi.bak -e 's/cli_args/tmux_options/' *.yml $ perl -pi.bak -e 's/tabs/windows/' *.yml $ perl -pi.bak -e 's/^project_//' *.yml $ perl -pi.bak -e 's/-2$/-l -2/' *.yml
The last change there is because with just the "-2" in tmux_options I got the error:
in `tmux_options': undefined method `strip' for -2:Fixnum (NoMethodError)
Sat, 22 Jun 2013
Keywords: linux ubuntu postfix Return-Path Sender From
My family connects to my mail server in order to send mail. But everyone has mail addresses that differ from their login names. On sending mail, postfix would add a Return-Path header matching my username on the mail server. In order to have the correct Return-Path added, I created /etc/postfix/generic with the following content:
email@example.com firstname.lastname@example.org email@example.com firstname.lastname@example.org
And added to /etc/postfix/main.cf:
smtp_generic_maps = hash:/etc/postfix/generic
# postmap /etc/postfix/generic # service postfix restart
Passing that mail through another server running exim4, I added the following lines to /etc/exim4/exim4.conf:
no_local_from_check untrusted_set_sender = *
Sat, 17 Nov 2012
Merge newer changes on the branch you came from (eg master):
$ git rebase master
Merge your branch:
$ git merge [--no-ff] newbranch
Push a newly created branch upstream:
$ git push -u origin newbranch
-u makes your branch a tracking branch of upstream
Create a new tracking branch:
$ git branch -t newbranch origin/newbranch
Delete remote-tracking branch:
$ git branch -r -d origin/oldbranch
Delete remote branch: (see also http://git-scm.com/book/ch3-5.html)
$ git push origin --delete oldbranch
$ git rebase -i HEAD~5
Make a branch retroactively (see http://blogs.perl.org/users/mark_leighton_fisher/2012/11/when-to-create-a-branch-in-git.html):
$ git checkout -b newbranch $ git update-ref refs/heads/master origin/master
Merge a branch that should have been rebased:
$ git fetch https://github.com/user/repo.git upstream_branch:local_newbranch $ git checkout local_newbranch $ git rebase master $ git checkout master $ git merge -ff-only local_newbranch $ git branch -d local_newbranch
Create a branch for a pull request:
$ git pull https://github.com/user/repo.git upstream_branch:local_newbranch
Move a branch to a new commit:
$ git branch -f branch_name new_tip_commit
Look at a file from an previous revision:
$ git cat-file -p <sha1>:filename
Fri, 27 Jan 2012
Keywords: linux ubuntu notion
I use Notion as my window manager under Ubuntu. Notion is a fork of Ion.
Under Ubuntu 11.10 you can set Notion as your default window manager by creating the file /usr/share/xsessions/notion.desktop with the contents:
[Desktop Entry] Encoding=UTF-8 Name=Notion Comment=This session logs you into Notion Exec=notion Icon= Type=Application
Then edit /etc/lightdm/lightdm.conf:
and if you want to automatically login set:
where XXX is your username.
Fri, 28 Oct 2011
Keywords: Virtualbox shrink disk size minimise
Update - 19.07.2014
This is actually a little easier now. Or I know better, perhaps.
Again, there should be no snapshots.
1. On the VM install zerofree:
# aptitude install zerofree
2. Boot into single user mode.
3. Run zero free on each virtual disk:
# zerofree /dev/sda1 # zerofree /dev/sdb1
4. Power down the VM
(On a Windows guest, for steps 1-4 just download and run sdelete -z)
5. On Windows, compact each virtual disk:
> "c:\Program Files\Oracle\VirtualBox\VBoxManage" modifyhd root.vdi --compact
And you're done.
If you've been using VirtualBox for a while with dynamically allocated disks, you've probably found that the size of the virtual disk exceeds that of the data stored therein. Sometimes by quite some ammount. Once used, the disk space is never returned.
I recently bought an SSD and wanted to put one of my Ubuntu virtual machines on it, that being where I do most of my work. However, the three virtual disks being used by that VM had grown quite large - too large to store on my SSD. There were also snapshots in use, despite the VM apparently not using any. This, I suspect, may have been due to mounting a virtual disk from another VM which had snapshots. Or it might not. In any case, things were a little bit of a mess and I wanted to sort them out too.
The first thing I did was to clear out as much of the disks as I could that was just being used for storage. Then we get to the complicated part of trying to reduce their size. I have seen suggestions to use zerofree or resize2fs but it wasn't clear to me whether they worked with ext4. So here is the method I used.
1. Using VirtualBox 4.1.x, clone the VM. This removes all the problems with the snapshots and makes a single definitive copy of all the virtual disks. If you have more than one virtual disk, you could remove those disks beforehand, since copies of those disks are not actually required, though a copy of the disk containing the root filesystem is required.
2. Create new, empty virtual disks for each of your original disks.
3. Add these new empty disks to your VM, along with at least the copy of the root filesystem.
4. Start your VM, run fdisk and mkfs.ext4 or mkswap to create the filesystems.
5. Create mountpoints and mount your new and cloned disks.
6. For all filesystems except the root filesystem, run cp -a to populate the new disk either from the clone, if you made one, or just from wherever they are mounted on the VM.
7. For the root filesystem do the same, but this must be done from the clone.
8. Assume your new root filesystem is mounted as /mnt/root. Run:
# mount -o bind /proc /mnt/root/proc # mount -o bind /dev /mnt/root/dev # mount -o bind /dev/pts /mnt/root/dev/pts # mount -o bind /sys /mnt/root/sys
Edit /etc/fstab to reflect your new disk layout. If possible, it might be easier if you just mount the root filesytem at first and don't use the UUID format.
# chroot /mnt/root # grub-install --root-directory=/ /dev/hda
Replace hda with whichever device you are booting from.
# update-grub # exit
9. Create a new virtual machine, use your cloned one, or reuse your old one. Attach the appropriate disks and start the VM. If you are lucky, grub will be set up and the VM will boot.
10. Find out the UUIDs of your partitions by running blkid. Edit /etc/fstab appropriately and reboot.
11. Copy averything to where you want it to be. (My SSD.)
And that's all there is too it!
Tue, 26 Jul 2011
With Cyanogenmod I kept getting the message:
"the process android.process.media has stopped unexpectedly"
when running Market or a music player.
The fix for me was to umount and then remount the SD card.
Wed, 10 Nov 2010
Keywords: Webalizer Geoip database package missing dependency
I was getting the following error message from cron:
Error Opening file /usr/share/GeoIP/GeoIP.dat
Turns out it was coming from webalizer. It seems that there is a package dependency missing. The solution was fairly simple:
aptitude install geoip-database
Mon, 18 Oct 2010
Keywords: Virtualbox Ubuntu 10.10 crashes timer noapictimer nohz=off highres=off grub
I recently bought myself a new laptop. It's a rather nice HP Envy 14. Unfortunately no linux distribution properly supports it yet and so I run a Ubuntu guest virtual machine on it under VirtualBox with Windows 7 as the host.
Recently the VM started crashing. It would stop accepting keyboard input, and wouldn't shut itself down nicely using the mouse either from within Ubuntu or from VirtualBox. The only solution was to get VirtualBox to poweroff the VM. I upgraded Ubuntu to 10.10 and VirtualBox to 3.2.10, hoping to fix the problem, but it didn't help.
What did help though, was adding the following startup options:
noapictimer nohz=off highres=off
These can be added to the GRUB_CMDLINE_LINUX_DEFAULT line in /etc/default/grub, then run update-grub and the problem seems to be fixed.
Although sound under a VM isn't really the best idea, I just can't find any music players that I like which run under windows, and so I use Amarok 1.4. (No, I don't like Amarok 2.) Previously I was getting more frequent crashes whilst playing music. With this fix I've not had any crashes, even when playing flac files. Looking at the solution, this makes sense.