My Computer related stuff...

Mac OSX: shell-script to get Network configuration

#!/bin/bash
# Filename : GetCurrentNetworkLocation.sh
# Version  : $Revision: 1.1 $
# Author   : Dieter Demerre
# Copyright: (c) 2010- Dieter Demerre
# Licence  : (g) GPL2 (http://www.gnu.org/licenses/)
# Package  : Mac Os X system scripts
# Project  : Network and configuration
# History  :
#  2010-01-12 ddemerre 0.1 Initial implementation
#----------------------------------------------------------------------
# Description
#  script that will (try to) determine what's the current network location
#----------------------------------------------------------------------
INPUT=/Library/Preferences/SystemConfiguration/preferences.plist;

function error
{
  echo ${@} >&2;
}
if [ ! -r "${INPUT}" ]; then
  error "cannot read plist file ${INPUT}"
  exit -1;
fi

#Get key of Currently selected Set 
setInfo=$(grep -A 1 "CurrentSet" "${INPUT}");
if [ 0 -ne ${?} ]; then
  error "could not retrieve CurrentSet info (${?})."
  exit -2;
fi
currentSet=$(echo ${setInfo}|sed 's/[^ ]* *//;s/\/Sets\/\(.*\)<\/string>/\1/;');

#Get line number in file for (start) of definition of the selected set 
notBefore=$(grep -n "<key>${currentSet}</key>" "${INPUT}"|cut -d':' -f 1);
if [ -z ${notBefore} ] || [ ${notBefore} -le 0 ]; then
  error "did not find key reference ${currentSet} in input (result ${notBefore})";
  exit -2;
fi

# Consider only all lines following the definition-start of the set 
lines=$(wc -l "${INPUT}"|awk '{print $1;}');
tail=$(( (lines - notBefore + 1) * 1));
nameInfo=$(tail -n ${tail} "${INPUT}" | grep -A 1 '<key>UserDefinedName</key>');

# And get the string value of the UserDefinedName key.
echo ${nameInfo}|sed 's/[^ ]* *//;s/<string>\([^<]*\)<\/string>.*/\1/;';

Labels: apple, network, script

posted by Dieter @ 16:59 0 comments

Airport Extreme, loosing WAN (adsl2 bridged) unnoticed on regular basis

Labels: adsl2, airport extreme, apple, bug, hardware, network, wifi

posted by Dieter @ 20:41 0 comments

secure synergy

• installed cygwin with openssh on the windows machine.


• put the public ssh-key of my user on laptop into authorized_keys of desktop


• on laptop: ssh desktopuser@desktop -L24801:localhost:24800


• on laptop: synergyc localhost:24801

#!/bin/bash
while /bin/true; do
  for host in worklogin@desktop-work homeuser@imac-home; do
    ssh -L24801:localhost:24800 -f ${host} sleep 5;
    [ ${?} = 0 ] && synergyc --no-restart --no-daemon localhost:24801;
  done
done

#!/bin/bash
# will start proxy-ssh-command in detached screen.

CLIENTNAME=laptopname;

if [ -z "${DISPLAY}" ]; then
  echo "no DISPLAY variable set" >&2;
  exit;
fi

if [ "$( id -n -u )" = "root" ]; then
  SUDO="sudo -u laptopuser ";
  screenname=root_synergy_proxy;
else
  SUDO="";
  screenname=user_synergy_proxy;
fi

case "$(hostname)" in
(${CLIENTNAME}|${CLIENTNAME}\.*)
  proxycommand="while /bin/true; do
    for host in DT1user@desktop1 DT2user@desktop2 DT3user@desktop3; do
      ${SUDO} ssh -L24801:localhost:24800 -f \${host} sleep 5;
      [ \${?} == 0 ] && synergyc --no-restart --no-daemon localhost:24801;
    done;
  done;";
;;
(*)
  # only allow invocation on configured machine.
  echo "this script should only run on ${CLIENTNAME}.">&2;
  exit;
;;
esac

#remove possible defunct screens
screen -wipe

#check for existing (running) screen
screen -list|grep -e '\<[0-9]\{1,\}\.'${screenname}'\>' >/dev/null 2>&1;

case "${?}" in
(0) # depending on existing screen, retrieve it (if requested)
    [ $# -eq 1 ] && [ "$1" = "screen" ] && screen -dr ${screenname};
    ;;
(*) # launch the screen instruction (with screen on console if requested)
    [ $# -eq 1 ] && [ "$1" = "screen" ] && resume="" || resume="-d -m";
    screen ${resume} -S ${screenname} bash -c "${proxycommand}"; 
    ;;
esac;

Labels: cygwin, hardware, network, security

posted by Dieter @ 15:21 1 comments

keyboard and mouse sharing over network

• Start synergy (on windows machine)
  
• select "share this computer's keyboard and mouse"
  
• press "configure" (see image right).
  
  
• press the + button in the screens-section (once for all machines you wish to configure, add the server like this AND all the clients.
  
• in the "Links" section, configure where which display is "logically positioned", so when leaving the display (using the mouse-cursor) at one side, where should it enter (at what side).
  Also provide (if needed) a "return"-link:
  (DON'T THINK that if you configure to leave machine-A through your left-screen-side for the right-screen-side of machine-B, you'll automatically configure the right-side of machine-B to return to the left-side of machine-A, because you don't).
  

• Now you don't have to configure your client, only to launch it and tell it what server to connect. [code]synergyc server[/code] (see man synergyc for extra options).
  

• server to launch automatically (using the "autostart" button on the windows synergy application).
  

• I created a script synergyc_start with the instructions to execute:
  #!/bin/sh
synergyc servername
  
• and added an invocation of that script in /etc/gdm/Init/Default, before the sysmodmap=-line.
  
• and added another invocation of that script in /etc/gdm/PreSession/Default before the XSETROOT=-line.
  

Labels: hardware, linux, network

posted by Dieter @ 14:38 0 comments

Changing MAC address for ethernet card (in linux)

sudo ifconfig eth0 hw internet 00:01:02:03:04:05

Labels: hardware, linux, network

posted by Dieter @ 08:53 0 comments