encrypted partion on debian 8

Encrypting partitions is fun, but also a bit unintuitive.

# install dependencies
sudo apt-get install cryptsetup

# setup luks on desired partition
sudo cryptsetup -y -v luksFormat /dev/sdb1

# init mapper device (and persist this setting)
sudo cryptsetup luksOpen /dev/sdb1 sdb1_crypt
sudo sh -c 'echo "sdb1_crypt /dev/sdb1 none luks" >> /etc/crypttab'

# format block device
sudo mkfs.ext4 /dev/mapper/sdb1_crypt

# add device to fstab
sudo mkdir /mountpoint
sudo sh -c 'echo "/dev/mapper/sdb1_crypt /mountpoint ext4 defaults 0 1" >> /etc/fstab'

# mount
sudo mount /mountpoint


cron restart process if it died

I just put something like this in my crontab. It's quick and dirty, but it works.

*/1 * * * * [ -z "`ps -ef | grep -v grep | grep '<command>'`" ] && <command>

For those rare cases when writing a daemon just does not pay off.

screen capture on ubuntu 14.04 (trusty thar)

list your pulse devices:

pactl list

record with avconf (which is a weird version of ffmpeg):

avconv -video_size 1024x768 -framerate 20 -b $((10*1024))k -f x11grab -i $DISPLAY -f pulse -ac 2 -i "alsa_input.usb-0b0e_Jabra_SPEAK_510_USB_1C48F9E60C09020A00-00-USB.analog-mono" -threads 2 -vcodec libx264 -acodec mp3 -preset ultrafast output.mp4

install epson L355 scanner driver on debian

Short and painless:

wget https://download2.ebz.epson.net/iscan/general/deb/x64/iscan-bundle-1.0.0.x64.deb.tar.gz
tar -xf iscan-bundle-1.0.0.x64.deb.tar.gz
sudo bash iscan-bundle-1.0.0.x64.deb/install.sh

grep epkowa /etc/sane.d/dll.conf \
    || sudo bash -c 'echo epkowa >> /etc/sane.d/dll.conf'

# you printer is very like different form
# so adjust accordingly
grep 'net 192\.168\.123\.4' /etc/sane.d/epkowa.conf \
    || sudo bash -c "echo 'net' >> /etc/sane.d/epkowa.conf"

This of course is a security nightmare so don't forget to do this only in a VM or better yet on dedicated hardware with no sensitive data / network access.


eclipse search code

If it comes to IDEs Eclipse is a beast. Here are some shorts-cuts I use really a lot lately, they're for searching and navigating through code:

  • search for files: [Ctrl+Shift+r]
  • search for java methods: [Ctrl+Shift+m]
  • search for java classes: [Ctrl+Shift+t]

experimenting with sending processes to backround

Sometimes I run tasks over ssh without starting screen first. I tend to regret that. So started experimenting with detaching running processes from the shell. (I'm using zsh btw. so this might not work with other shells)

Note this is just experimental, don't expect this to work. And never trust this for keeping critical processes alive.

# press [CRTL+Z] for putting a already running prozess in background

# display a list of jobs

# make a process run in background
bg %1

# keep the process running even when the termianl (ssh connection) quits
# in bash this should be: disown -h %1
disown %1

# find pids of disowned processes:
ps aux | grep commandName

# bring a disowned process to the foreground:
reptyr 1234

source: http://serverfault.com/questions/55880/moving-an-already-running-process-to-screen