Interceptor 1.2.9
Copyright 2011 Christophe Gros <>


This program is free software, and has been released under the GPL licence.
You should have received a copy of the GNU Library General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

Interceptor is a Plasmoid for KDE4 on Posix systems, such as Linux. Its role is to intercept (catch) the log info from the syslog daemon, to flash whenever a log line is processed, and display it on a panel.

In addition, interceptor can send an adequate notification to the KDE4 systray when a log line matches a given regular expression.This notification can even include an interaction, i.e. a button is displayed, that executes a command when clicked.

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You can download the interceptor's package here.




In order to install interceptor, you need the KDE4 devel packages installed on your computer, and also the cmake utility. Then, from a shell, run the following commands:

tar xjf <your path>/interceptor-1.2.9.tar.bz2
cd interceptor
mkdir build
cd build
cmake ../interceptor
su   or   sudo -s       on Ubuntu & al.
make install

Notice that <your path> is the path where you downloaded the interceptor package. You probably need to give the root password when "su" is executed.


Before using interceptor, you must execute AS ROOT the mkintfifos utility. Then reboot the computer. If you upgrade from a prior version, you should edit the /etc/syslog.conf or /etc/rsyslog.conf file and replace all the lines containing *. with *.=


*.debug     |/var/run/interceptor/debug


*.=debug     |/var/run/interceptor/debug;RSYSLOG_TraditionalFileFormat


On the desktop or on the taskbar, select Add Plasmoids. You should see the Interceptor icon. Double-click on it or drag it onto the desktop. As an icon, the little jet will flash green when a debug, info or notice message is coming in, flashes orange when warning or error and red otherwise.
If needed, click on the icon in order to display the panel.
If you double-click on a message, a dialog box appears, that displays its content.


Right-click on the icon or on the panel and select Interceptor Settings.


The Notifications dialog box will allow you the edit the action performed when a log line matched a given pattern.
Click on New and a empty notification is created. Give a name, a Qt RegExp pattern (see this introduction), a comment that will be displayed on the systray message box and a possible icon. Just give the icon name. No path or extention is needed.


Comment=Hey! Your wifi is down!!

The qt RegExp is always tested on a line with the following format:


If the comment is where level is debug, warning, etc... source, the source of the message, host the hostname and the message text. If the comment is empty, the current line is ignored, so that you can filter out unwanted messages.

The displayed comment accept variables matching the captured substrings in a RegExp pattern.

 $1 the 1st pattern
 $2 the 2nd
 $3 3rd
 $4 4th

and $D for the message date and $T for its time.


Pattern=usb 1-1: (.*): TX timeout
Comment=Hey! your wifi $1 was down at $T!

An anonymous button has been added, that shows the chosen icon (if any) of the selected notification. Click on this button and you will be able to select more easily your icon from a file dialog box with a possible preview.

Anti-flooding system.

A daemon or the kernel may send bursts of the same message, typically when reading a damaged CD. In order to avoid a flooding of useless messages, a delay is associated with each known pattern, so that an incoming message will be abandoned if an equivalent log line has already been displayed within this delay.

On the notifications editor, you can test your current RegExp with a sample line. Then click on the test button and Interceptor will tell you whether the line matches your regular expression or not.

The third line of the notification declaration optionaly proposes to set up an interaction. The format of this interaction is a title and a command separated with a ::
the command part of the line is also subject to variable substitutions.


InterAction=Send immediate Email::echo "Security breach on $1 at $T" | mail -s "Security breach" root@localhost

Interceptor works with the KDE4 systemsettings. You can add other behaviors to your notifications with the Configuration of the Notifications, such as playing a sound, executing a command or even speaking!


Christophe Gros <skylendar at yahoo dot. com>
Septembre 8th, 2011