record a video with ffmpeg from a webcam with audio 
First activate and rise webcam audio input level with alsamixer.

ffmpeg -f video4linux2 -i /dev/video0 -pix_fmt yuv420p -s vga -r 8 -f alsa -ac 1 -ar 16000 -i hw:1,0 -vcodec mpeg4 -b 400k -acodec libmp3lame -ab 80k video.avi

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key remap on keyboard for console and X 
I got a funny viennese dialect keyboard, but after start using it i missed a key '<,>,|' :-(

So i searched for a way to remap 'AltGr + y' to '|', 'AltGr + ,' to '<' and 'AltGr + .' to '>'


evaluate the key to change with

#> sudo showkey -s

press the key

here y is 0x2c = 44
here , is 0x33 = 51
here . is 0x34 = 52

test remap with

echo "altgr keycode 44 = bar" | loadkeys

bar is a symbolic name i found at German-Howto

Finally i extended /etc/rc.local with
LOADKEYS=$(which loadkeys)
if [ -x $LOADKEYS ]; then
cat << EOT | $LOADKEYS
altgr keycode 44 = bar
altgr keycode 51 = less
altgr keycode 52 = greater


evaluate the key to change with

#> xev

press the key

here y is keycode 52
here , is keycode 59
here . is keycode 60

test remap with

xmodmap -e "keycode 52 = y Y y Y bar"

dump keys with

#> xmodmap -pke > ~/.Xmodmap

remove all lines except lines starting with desired keycodes to change.

my ~/.Xmodmap now looks like
keycode  52 = y Y y Y bar U203A guillemotright
keycode 59 = comma semicolon comma semicolon less multiply periodcentered
keycode 60 = period colon period colon greater division U2026

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Audio only capture from a video/audio usb capture stick 
#> apt-get install xawtv

I assume the usb stick become /dev/video0 and audio became card 1 (card 0 is an onboard audio device)

#> v4lctl -c /dev/video0 setattr input Composite1
#> v4lctl -c /dev/video0 setattr mute off
#> amixer -c 1 sset Line,0 50%,50% unmute cap

test with:

#> arecord -D hw:1,0 -f S16_LE -c2 -r48000 | aplay

To execute this commands automatically on plugin udev could be used:

I have a cheap msi movie vox mini stick using em28xx driver with an option set:

options em28xx card=38

ACTION=="add", KERNEL=="video*", DRIVERS=="usb", ATTRS{idVendor}=="eb1a", ATTRS{idProduct}=="2861", RUN+="/usr/bin/v4lctl -c /dev/%k setattr input Composite1"                      
ACTION=="add", KERNEL=="video*", DRIVERS=="usb", ATTRS{idVendor}=="eb1a", ATTRS{idProduct}=="2861", RUN+="/usr/bin/v4lctl -c /dev/%k setattr mute off"
ACTION=="add", KERNEL=="video*", DRIVERS=="usb", ATTRS{idVendor}=="eb1a", ATTRS{idProduct}=="2861", RUN+="/usr/bin/logger video init %k done"
ACTION=="add", KERNEL=="controlC[0-9]*", DRIVERS=="usb", ATTRS{idVendor}=="eb1a", ATTRS{idProduct}=="2861", RUN+="/usr/bin/amixer -c %n sset Line,0 50%,50% unmute cap"
ACTION=="add", KERNEL=="controlC[0-9]*", DRIVERS=="usb", ATTRS{idVendor}=="eb1a", TTRS{idProduct}=="2861", RUN+="/usr/bin/logger audio init card %n done"

v4lctl needs some time to finish, to check the settings use:

v4lctl -c /dev/video0 show

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initramfs script's to backup system's (also raid1) and restore from a usb stick 
These are scripts to backup system's and build an image for an usb stick or kvm for testing:


The only thing to configure is the backup-script:

All your partition's must have an UUID.

With "uuidgen | xargs mkswap /dev/sda1 -U" and "uuidgen | xargs tune2fs /dev/sda1 -U" you can generate one.

This is an example of a backup of a system with two partitions:

cat >root_exclude <<EOF

cat >var_exclude <<EOF

sudo tar -cSp --one-file-system --numeric-owner --atime-preserve \
--exclude-from=root_exclude -f $(hostname).root.tar /

sudo tar -cjSp --one-file-system --numeric-owner --atime-preserve \
--exclude-from=var_exclude -f $(hostname).var.tar.bz2 --directory /var .

uuid() { sudo blkid -o value -s UUID /dev/$1; }
fstype() { sudo blkid -o value -s TYPE /dev/$1; }
inodesize() { sudo tune2fs -l /dev/$1 | grep "Inode size" | sed -e 's/[^0-9]//g'; }
raiduuid() { sudo sed -n "s/^.*$1.*UUID=\(.*\)/\1/p" /etc/mdadm/mdadm.conf; }
partitioninfo() { echo "$(echo $1|sed -e 's/[^0-9]//g') $(uuid $1) $(fstype $1)"; }

cat >$(hostname).cfg <<EOF
ARCHIVES="$(partitioninfo sda2) $(hostname).root.tar.bz2
$(partitioninfo sda3) $(hostname).var.tar.bz2"
SWAP="1 $(uuid sda1)"
GRUB1_INODESIZE=$(inodesize sda2)
* for each tar an exlude-file can be defined
* files are named HOSTNAME.root.tar.bz2, HOSTNAME.var.tar.bz2 and HOSTNAME.cfg
* this backup needs a small config-file (HOSTNAME.cfg)

DISK_PARTITIONS is used by sfdisk and has to be definded in its INPUT FORMAT
ARCHIVES takes a config line for each partition with an optional tar archive at the end
SWAP starts with the number of the partition and the uuid of it
GRUB needs the version of grub
GRUB1_PARTITION is only needed for grub 1 and is the boot partition (counting starts with 0)
GRUB1_INODESIZE is needed because older grub1 can not boot with a filesystem of different inode size

For a raid1 system with only one filesystem the config looks like
DISK_PARTITIONS=",8000,S;,,L,* ,8000,S;,,L,*"
RAID_UUIDS="$(raiduuid md0) $(raiduuid md1)"
ARCHIVES="$(partitioninfo md1) $(hostname).root.tar.bz2"
SWAP="0 $(uuid md0)"
GRUB1_INODESIZE=$(inodesize md1)
After running the backup script HOSTNAME.root.tar.bz2, HOSTNAME.var.tar.bz2 and HOSTNAME.cfg are build.
Now you can run ./ or copy these files to your backup server (where you put the files from other systems) and run there ./ Now you got a directory called image with all your archives, your running kernel and a configured initrd (initramfs).
With ./ /dev/STICKDEVICE your stick to restore is prepared (Warning all data on the stick is erased!).

With kvm you can test the restore process:

Therefore run sudo ./
The build image can be mounted with sudo ./ to ./mnt and unmounted with sudo ./
Test the image with and test the restored image with ./

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php script for sispmctl (power supply switching) 
#> apt-get install sispmctl

Switch Socket on with sispmctl -o 1, off with sispmctl -f 1 and get status with sispmctl -m all

To have premission for a webserver to execute the command:

ACTION=="add", SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", \
ATTRS{idVendor}=="04b4", ATTRS{idProduct}=="fd13", \
GROUP="www-data", MODE="0660"
Because sometimes a wrong status came back i read it twice and compare it

function sispm_status() {
$pins1=array(0=>'0'); $pins2=array(0=>'1');
while ($pins1 !== $pins2) {
exec("/usr/bin/sispmctl -qnm all", $pins1);
exec("/usr/bin/sispmctl -qnm all", $pins2);
return $pins1;
$pins = sispm_status();

if (isset($_POST['update']))
for ($i = 0; $i <= 3; $i++)
if (isset($_POST["pin$i"])) {
if (!$pins[$i]) exec("/usr/bin/sispmctl -qno ".($i+1)); }
else if ($pins[$i]) exec("/usr/bin/sispmctl -qnf ".($i+1));

$pins = sispm_status();

<form method="post">
<input type="checkbox" name="pin0" value="1" <?= ($pins[0]?'checked':'') ?>> Socket 1<br>
<input type="checkbox" name="pin1" value="1" <?= ($pins[1]?'checked':'') ?>> Socket 2<br>
<input type="checkbox" name="pin2" value="1" <?= ($pins[2]?'checked':'') ?>> Socket 3<br>
<input type="checkbox" name="pin3" value="1" <?= ($pins[3]?'checked':'') ?>> Socket 4<br>
<input type="submit" name="update">


use strict;
use warnings;
use CGI;

my $cgi = CGI->new();

my @ports=("PC","Printer","-","-");

print "Content-type: text/html\n";

print "\n";

print "<HTML><HEAD><TITLE>USB Steckdosenleiste</TITLE><META http-equiv=\"refresh\" content=\"60;steckdose.cgi\"></HEAD>\n\n";

print "<BODY>\n";

for my $port ($cgi->param()) {
if ($cgi->param($port) eq "on") { system "/usr/bin/sispmctl -q -o $port"; }
elsif ($cgi->param($port) eq "off") { system "/usr/bin/sispmctl -q -f $port"; }

print "<H1>USB Steckdosenleiste</H1><UL>\n";
my @states = `/usr/bin/sispmctl -q -g all`;
my $cnt = 1;
for my $state (@states) {
if ($ports[$cnt-1] ne "-") {
if ($state eq "off\n") { print "<LI>".$ports[$cnt-1]." ist ausgeschaltet [<A href=\"steckdose.cgi?$cnt=on\">einschalten</A>]\n"; }
else { print "<LI>".$ports[$cnt-1]." ist eingeschaltet [<A href=\"steckdose.cgi?$cnt=off\">ausschalten</A>]\n"; }
print "</UL>\n";

print "</BODY></HTML>"

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