Posts Tagged ‘Gnome’

Quick shortcut to lock your Linux computer desktop (Few words on Linux screensavers)

Thursday, November 20th, 2014

Locking the PC while going for a coffee break, Lunch or toilet is longly used to secure physically your PC display from spying eyes or prevent you from  someone to install a spying software or leak private data from PC HDD to an USB drive.
People who are coming from the wonderful MS Windows OS   are certainly used to quick shortcut key combination to lock PC screen with:

Windows key + L


So how to do Lock Screen on Linux?

On Linux locking your Screen the Quick Shortcut is:


Locking the screen is done (depending on the Linux distribution) by using by either using historically famous XScreenSaver if non-gnome / KDE graphical environemnt is used or if in Linux Gnome GUI with  gnome-screensaver and on KDE desktop manager with kscreenlocker.


Exact command executed on CTRL + ALT + L keypress on GNOME is:

gnome-screensaver-command -l

On KDE to manually lock screen command is:


Nomatter whether with GNOME or KDE its worthy mention that xscreensaver is more Screensaver rich than kscreenlocker and gnome-screensaver as it includes about 200 different Screensavers making screen nice to watch when you come back from a lunch.

For people with Windows key keyboard who are too used to using Windows XP / 7 lockreen WIN + L key shortcut to make Windows (key) + L keys combination work on Linux with GNOME desktop:

System -> Preferences -> Keyboard Shortcuts

Make Win + L keys combination work on Linux with KDE desktop

  1.  "System Settings" (KDE menu).
  2. Choose "Keyboard & mouse" (on "General" tab).
  3. Choose "Global Keyboard Shortcuts" on the left.
  4. Choose "Run Command Interface" from "KDE component" dropdown list.
  5. Choose "Lock session".
  6. Select "Custom".
  7. Click on "None" (button changes to "Input…").
  8. Compose your desired sequence by pressing appropriate buttons on your keyboard.
  9. Click "Apply".


For other desktop environments like Window Maker you can use xmodmap command to bind Win + L keys

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Screenshot expanded menus on GNOME / KDE in Linux and BSD desktop

Thursday, June 19th, 2014


If you're using actively Linux or FreeBSD on Desktop PC and experimenting with software, taking personal notes, developing software for Linux, writting documentation, participating in free software community etc., you will certainly need use screenshot heavily.

Taking a screenshot in Linux is done in same way as in any modern operating system by using the Print Screen (PrtScr) button, however there are few Nuts & Bolts of Linux screenshotting, to take advantage of full power of screenshot creation (i.e. be able to do some screenshot customization) which are not offered by default screenshot utilities (GNOMEgnome-screenshot and KDE's KSnapshot)

Here are few useful Linux /BSD Screenshot Tips and Tricks:

If you have done screenshots of Linux running programs more than few times already, you have probably noticed the usual way to screenshot by pressing Print Screen (PrtScr) button to take snapshot of the expanded GNOME / KDE menu is not working. In that order of thought you probably wondered whether it is possible to take a screenshot of an expanded menus? As a Linux user, I've been asking myself this question too, and feeling irritated that  I cannot prepare screenshot of a GNOME running application expanded menu. I've found two ways (though there are probably many more to make screenshot of an expanded Linux menu). Here is how:

Create screenshot of running application expanded menus

1. Taking screenshot of expanded menu using the command line

As with everything in Linux, there aremultiple ways to make screenshot of expanded Linux menus.

  • Make timed screenshot of the screen scheduled to screenshot after a set number of seconds.

The quickest way for to screenshot expanded menu is to use gnome-panel-screenshot or ksnapshot from command line. It is interesting pressing Prt Sc kbd button in GNOME invokes gnome-screenshot and in KDE uses ksnapshot


gnome-panel-screenshot --delay 5


To not spend time running it from gnome-terminal (in GNOME desktop), press Alt+F2 (simultaneously) and use the Run Application command shortcut.


This will instruct Screenshot utility to wait for 5 seconds before capturing your desktop this should be enough time for you to go to navigate to expanded menu which you want to get screenshotted.


  • Make timed screenshot of the screen in GUI with GIMP


(If you're wonderhing what kind of Linux is on screenshot – this is Trisquel – Run Free! GNU / Linux. It is a Spanish distribution focused on providing 100% free software in it – without proprietary firmware or software. Trisquel is based on Debian and uses the dpkg / apt-get package managers. Trisquel is a recommended Linux to use by Richard Stallman and The Free Software Foundation).
To make timed screenshot with GIMP use menus:


File -> Create -> Screenshot



Chosee whether you want to Take screenshot of the entire screen or a Region to Grab and set your wanted Delay

Screenshot will be prepared on $HOME/Desktop, after set time.

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Use apt-get with Proxy howto – Set Proxy system-wide in Linux shell and Gnome

Friday, May 16th, 2014


I juset setup a VMWare Virtual Machine on my HP notebook and installed Debian 7.0 stable Wheezy. Though VMWare identified my Office Internet and configured automatically NAT, I couldn't access the internet from a browser until I remembered all HP traffic is going through a default set browser proxy.
After setting a proxy to Iceweasel, Internet pages started opening normally, however as every kind of traffic was also accessible via HP's proxy, package management with apt-get (apt-get update, apt-get install etc. were failing with errors):

# apt-get update

Ign cdrom://[Debian GNU/Linux 7.2.0 _Wheezy_ – Official i386 CD Binary-1 20131012-12:56] wheezy Release.gpg
Ign cdrom://[Debian GNU/Linux 7.2.0 _Wheezy_ – Official i386 CD Binary-1 20131012-12:56] wheezy Release
Ign cdrom://[Debian GNU/Linux 7.2.0 _Wheezy_ – Official i386 CD Binary-1 20131012-12:56] wheezy/main i386 Packages/DiffIndex
Ign cdrom://[Debian GNU/Linux 7.2.0 _Wheezy_ – Official i386 CD Binary-1 20131012-12:56] wheezy/main Translation-en_US
Err wheezy Release.gpg
  Could not connect to ( – connect (111: Connection refused)
Err wheezy-updates Release.gpg
  Unable to connect to
Err wheezy/updates Release.gpg
  Cannot initiate the connection to (2607:ea00:101:3c0b:207:e9ff:fe00:e595). – connect (101: Network is unreachable) [IP: 2607:ea00:101:3c0b:207:e9ff:fe00:e595 80]
Reading package lists…


This error is caused because apt-get is trying to directly access above http URLs and because port 80 is filtered out from HP Office, it fails in order to make it working I had to configure apt-get to use Proxy host – here is how:

a) Create /etc/apt/apt.conf.d/02proxy file (if not already existing)
and place inside:

Acquire::http::proxy::Proxy "";
Acquire::ftp::proxy::Proxy "";

To do it from console / gnome-terminal issue:
echo ''Acquire::http::Proxy "";' >> /etc/apt/apt.conf.d/02proxy
echo ''Acquire::ftp::Proxy "";' >> /etc/apt/apt.conf.d/02proxy

That's all now apt-get will tunnel all traffic via HTTP and FTP proxy host and apt-get works again.

Talking about Proxyfing Linux's apt-get, its possible to also set proxy shell variables, which are red and understood by many console programs like Console browsers lynx, links, elinks  as well as wget and curl commands, e.g.:


export http_proxy=
export https_proxy=$http_proxy
export ftp_proxy=$http_proxy
export rsync_proxy=$http_proxy
export no_proxy="localhost,,localaddress,"

For proxies protected with username and password export variables should look like so: echo -n "username:"
read -e username
echo -n "password:"
read -es password
export http_proxy="http://$username:$password@proxyserver:8080/"
export https_proxy=$http_proxy
export ftp_proxy=$http_proxy
export rsync_proxy=$http_proxy
export no_proxy="localhost,,localaddress,"

To make this Linux proxy settings system wide on Debian / Ubuntu there is the /etc/environment file add to it:


To make proxy global (systemwide) for most (non-Debian specific) Linux distributions shell environments create new file /etc/profile.d/ and place something like:

function proxy(){
echo -n "username:"
read -e username
echo -n "password:"
read -es password
export http_proxy="http://$username:$password@proxyserver:8080/"
export https_proxy=$http_proxy
export ftp_proxy=$http_proxy
export rsync_proxy=$http_proxy
export no_proxy="localhost,,localaddress,"
echo -e "nProxy environment variable set."
function proxyoff(){
unset http_proxy
unset https_proxy
unset ftp_proxy
unset rsync_proxy
echo -e "nProxy environment variable removed."

To set Global Proxy (make Proxy Systemwide) for a user in GNOME Desktop environment launch gnome-control-center

And go to Network -> Network Proxy



To make proxy settings also system wide for some GUI Gnome GTK3 applications

gsettings set org.gnome.system.proxy mode 'manual'
gsettings set org.gnome.system.proxy.http host ''
gsettings set org.gnome.system.proxy.http port 8080

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How to disable GNOME popup notification in Debian Wheezy Linux

Friday, August 2nd, 2013

how to disable remove GNOME 2 / 3 popup e mail notification  Debian Ubuntu Linux screenshot

I found it very annoying to have a pop-up notification every time I receive a new email it is just pointless there especially, when I already use Thunderbird (IceDove) to fetch my email via pop3. This pop-up notification though planned to be useful messes with my Desktop and breaks the habit on how I'm used to old GNOME interface…. I remember same popup notification was present on older Fedora releases (back in time when I used Fedora Linux for my Desktop).

disable Gnome popup notification new email Debian GNU Linux Wheezy 7 screenshot

My logical guess was in order to disable popup notification in GNOME 3 I had to tamper with gconf-editor. In gconf-editor config database there is:

Apps -> Notification daemon

Problem it is not possible to turn it off. Only available change options are:

default-sound, popup_location, sound_enabled, and theme

After some time of try / fail attempts I found the solution on linuxquestions forum, its quite raw solution but it works, all I had to do is change permissions of /usr/lib/notification-daemon/notification-daemon;

debian:~# chmod 0000 /usr/lib/notification-daemon/notification-daemon

Another thing that is handy to disable is POP UP Window with warning that you have low disk space on Hard Drive.

The warinng for Disk space is very annoying and popups up on every GNOME boot. Actually the hard drive with Low disk space is and old mounted partition in NTFS and I only use it to read data.

Here is how to disable HDD Notification Warnings in GNOME:

debian:~# chmod 0000 /usr/lib/gnome-disk-utility/gdu-notification-daemon

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Tracking multiple log files in real time in Linux console / terminal (MultiTail)

Monday, July 29th, 2013

Multitail multiple tail Debian GNU Linux viewing Apache access and error log in shared screen
Whether you have to administer Apache, Nginx or Lighttpd, or whatever other kind of daemon which interactively logs user requests or errors you probably already know well of tail command (tail -f /var/log/apache2/access.log) is something Webserver Linux admin can't live without. Sometimes however you have number of Virtualhost (domains) each configured to log site activity in separate log file. One solution to the problem is to use GNU Screen (screen – terminal emulator) to launch multiple screen session and launch separate tail -f /var/log/apache2/domain1/access.log , tail -f /var/log/apache2/domain2/access.log etc. This however is a bit of hack and except configuring screen to show multiple windows on one Virtual Terminal (tty or vty in gnome), you can't really see output simultaneously in one separated window.

Here is where multitail comes handy. MultiTail is tool to visualize in real time log records output of multiple logs (tails) in one shared terminal Window. MultiTail is written to use ncurses library used by a bunch of other useful tools like Midnight Command so output is colorful and very nice looking.

Here is MultiTail package description on Debian Linux:

linux:~# apt-cache show multitail|grep -i description -A 1
Description-en: view multiple logfiles windowed on console
 multitail lets you view one or multiple files like the original tail

Description-md5: 5e2f688efb214b063bdc418a705860a1
Tag: interface::text-mode, role::program, scope::utility, uitoolkit::ncurses,
root@noah:/home/hipo# apt-cache show multitail|grep -i description -A 1
Description-en: view multiple logfiles windowed on console
 multitail lets you view one or multiple files like the original tail

Description-md5: 5e2f688efb214b063bdc418a705860a1
Tag: interface::text-mode, role::program, scope::utility, uitoolkit::ncurses,

Multiple Tail is available across most Linux distributions to install on Debian / Ubuntu / Mint etc. Linux:

debian:~# apt-get install --yes multitail

On recent Fedora / RHEL / CentOS etc. RPM based Linuces to install:

[root@centos ~]# yum -y install multitail

On FreeBSD multitail is available to install from ports:

freebsd# cd /usr/ports/sysutils/multitail
freebsd# make install clean

Once installed to display records in multiple files lets say Apache domain name access.log and error.log

debian:~# multitail -f /var/log/apache2/access.log /var/log/apache2/error.log

It has very extensive help invoked by simply pressing h while running


Even better multitail is written to already have integrated color schemes for most popular Linux services log files

multitail multiple tail debian gnu linux logformat different color schemes screenshot
List of supported MulLog Color schemes as of time of writting article is:

acctail, acpitail, apache, apache_error, argus, asterisk, audit, bind, boinc, boinctail ,checkpoint, clamav, cscriptexample, dhcpd, errrpt, exim, httping, ii, inn, kerberos, lambamoo, liniptfw, log4j, mailscanner, motion, mpstat, mysql, nagtail, netscapeldap, netstat, nttpcache, ntpd, oracle, p0f, portsentry, postfix, pptpd, procmail, qmt-clamd, qmt-send, qmt-smtpd, qmt-sophie, qmt-spamassassin, rsstail, samba, sendmail, smartd, snort spamassassin, squid, ssh, strace, syslog, tcpdump, vmstat, vnetbr, websphere, wtmptail

To tell it what kind of log Color scheme to use from cmd line use:

debian:~# multitail -Csapache /var/log/apache2/access.log /var/log/apache2/error.log

multiple tail with Apache highlight on Debian Linux screenshot

Useful feature is to run command display in separate Windows while still following log output, i.e.:

[root@centos:~]# multitail /var/log/httpd.log -l "netstat -nat"

Multitail can also merge output from files in one Window, while in second window some other log or command output is displayed. To merge output from Apache access.log and error.log:

debian:~# multitail /var/log/apache2/access.log -I /var/log/apache2/error.log

When merging two log files output to show in one Window it is useful to display each file output in different color for the sake of readability

For example:

debian:~# multitail -ci green /var/log/apache/access.log -ci red -I /var/log/apache/error.log

multitail merged Apache access and error log on Debian Linux

To display output from 3 log files in 3 separate shared Windows in console use:

linux:~# multitail -s 2 /var/log/syslog /var/log/apache2/access.log /var/log/apache2/error.log

For some more useful examples, check out MultiTail's official page examples
There is plenty of other useful things to do with multitail, for more RTFM 🙂

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SumatraPDF Adobe Acrobat Reader free software ( Secure ) Alternative

Friday, July 19th, 2013

Whether you're forced to use MS Windows but still want to use as much as possible Free Software – i.e. Stay away from Non-Free Adobe Acrobat Reader. There is Sumatra PDF – a good alternative that reads well most of PDFs. For rendering PDF Sumatra PDF usees muPDF library. SumatraPDF is minimalistic software it does exactly what it is meant for – reads PDF. Unfortunately from version 0.6 of Sumatra there is DRM implemented (Digital Right Managements) so it is not possible to copy from DRM-ed documents.
Sumatra opens  following formats: Open XML Paper Specification, DjVu, EPUB, XPS, CHM, CBZ and CBR, and MOBI files.
As of  time of writting official Sumatra PDF version is at ver. 2.3.2

sumatra pdfafter install thank you screenshot

I've made mirror of Sumatra PDF 2.3.2 installer here , Sumatra PDF zipped is here

Sumatra pdf reader screenshot ms windows 7
Sumatra PDF works on Windows XP, Vista, Win 7 & 7

  One of key advantages of Sumatra PDF over Adobe Acrobat Reader is you don't need to update it all the time and it is much less likely that Sumatra PDF is hit by security flaw in PDF format. 

For people who use Linux / BSD or some other Unix and want to stay free from proprietary Adobe Acrobat Reader two nice alternatives are default's GNOME PDF reader Evince and KDE's Okular

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Workrave – Preverve health from RSI (Computer caused Repetitive Strain Injury) on Linux and Windows

Tuesday, June 25th, 2013

Prevent and heal repetitive strain injury RSI with workrave on Windows and Linux

Huge part of people professions nowadays includes being in front of PC Screen for almost a day. Staying on computer is addictive and even after job is done many people came back in front of the PC screen to play some games or just read something. Many might not know that this computer hanging is a costly thing as it slowly reflects negative our health and living balance. For geeky people who work in IT profession the threat is even bigger as we ITs tend to spend even more time in front of computers. The risk therefore for catching RSI (Repetitive Strain Injury), whether you have to deal with computers daily is very real.

For those who hear for RSI for first time, here is what it is as described in Wikipedia:

Repetitive strain injuries (RSIs) are "injuries to the musculoskeletal and nervous systems that may be caused by repetitive tasks, forceful exertions, vibrations, mechanical compression, or sustained or awkward positions"

For more on RSI check out Wikipedia Article here.

Thanksfully RSI is possible to reverse as well as prevent by giving regular breaks from computer screen on timely base and even can be configured to limit time you will spend on the PC. 

Just recently I found out about existence of  Workrave – program which helps you in reminding, when you have to give breaks from computer and makes you limit yourself on how long you use the PC.

Workrave is available for both Windows and Linux OS.

debian:~# apt-cache show workrave | grep -i description -A 3

Description-en: Repetitive Strain Injury prevention tool
 Workrave is a program that assists in the recovery and prevention of
 Repetitive Strain Injury (RSI). The program frequently alerts you to
 take micro-pauses, rest breaks and restricts you to your daily limit.

To give it a try on Debian / Ubuntu Linux, install with usual:

debian:~# apt-get install --yes workrave

Launch it by running:

hipo@debian:~$ workrave

or via GNOME menus:

Applications -> Universal Access -> Workrave

Once launched Workrave applet appears right on in GNOME main panel. Below is screenshot of it.
Workrave applet in Gnome debian Linux screenshot

Clicking on the sheep image, there are plenty of configuration menus from which to choose how Workrave will further behave. Its default behavior is quite agressive and suggests breaks too often so if you choose to follow default configuration you will quickly be bored and probably remove it from computer. Hence re-configuring Workrave to remind for breaks every one hour is a good timing in my opinion:

Configuring workrave to remind for breaks from computer every one hour screenshot

Workrave time for micro break screenshot



Workrave includes reminder with neck movement exercises, which if followed can severely de-stress and keep your neck healthy.

workrave prevent repetitive strain injury neck exercises screenshot gnu / linux

workrave prevent repetitive strain injury neck exercises screenshot gnu / linux and windows

The program has even statistics on how much breaks you take, how long it was used and various other interesting info, below is screenshot from statistics window:

Workrave usage statistics GNU Linux screenshot


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Remove password prompt on GNOME Shutdown / Restart on Debian and Ubuntu Linux

Saturday, June 1st, 2013

It is ultra annoying, that in newest Debian and Ubuntu releases with GNOME 3 Desktop environment on every shutdown or restart you need to type in Super User (root) password, to authorize shutdown / restart.

Generally prompting for root password on GNOME restart is obviously a good think from security point of view, but from usability one – especially on notebooks it is useless annoyance…

So after changing this behavior I came up with this tiny article on how to get rid of GNOME Shutdown / Restart password prompt.

There is a click button (on left of Auth prompt on Shutdown showing URL to XML policy rule from where this behavior is controlled. A really good hint to where to look for to change those annoying behavior…

 Here is how to change this new annoying behavior to old GNOME 2 default restart with no root password prompt .
linux:~# gedit /usr/share/polkit-1/actions/org.freedesktop.consolekit.policy

Find in XML source sections:

Restart the system when multiple users are logged in System policy prevents restarting the system when other users are logged in no auth_admin_keep
Stop the system when multiple users are logged in System policy prevents stopping the system when other users are logged in no auth_admin_keep

To change Restart and Shutdown GUI behavior to not prompt for password, you need to modify in above code:



After changes both sections should look like so:

<action id="org.freedesktop.consolekit.system.restart">
<description>Restart the system</description>
<message>System policy prevents restarting the system</message>

<action id="org.freedesktop.consolekit.system.restart-multiple-users">
<description>Restart the system when multiple users are logged in</description>
<message>System policy prevents restarting the system when other users are logged in</message>

That's all you finally get rid of the annoying prompt for root password. Enjoy 🙂

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Show / Restore missing Gimp 2.8 Toolbox Menu on Debian Wheezy 7.0 Linux

Tuesday, May 28th, 2013

After installing latest Debian Wheezy Linux on my Lenovo Thinkpad Notebook. One of first packages after very basic GNOME install was of course GIMP.

I edit images with GIMP mostly on daily basis, so life without GIMP is impossible…
Debian 7 comes with shiny new version of GIMP – GIMP 2.8. So far so good, but the problem is when started it for a first time, the default configuration is made in a way that it miss essential Gimp Panel Window (The Toolbox Window). Missing Brushes and selectors, move, scissors etc. is something really terrible.

My first guess was I can display it somehow from GIMP's View menu but after few minutes of try/errs I figured out this is not possible.

One menu I managed to displayed Toolbox in some mostly unusubale form, since they were not fitting well my 1024×768 resolution screen is via menus:

Windows -> Toolbox

Since this wasn't what I was looking for I spend some 10 minutes until I finally found "the fix". from menus:

Preferences -> Window Management -> Reset Saved Window Positions to Default Values

gimp 2.8 preferences menu screenshot debian gnu linux 7 wheeze screenshot

gimp 2.8 preferences menu restore saved window position to default values screenshot / display missing GIMP menus

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Linux Currency convert GUI tool KeuroCalc / Convert world currencies Desktop Linux application, Convert USD to EUR

Thursday, April 25th, 2013

keurocalc Linux convert us dollars to euro and to rest of major world currencies

If you happen to run a small business or you're just an adventurer who use Linux for his notebook Desktop. Sooner or later you will end up needing Linux software to convert between world currencies. Some might argue that such a software is obsolete since already there are the Google Currency Converter and plenty of other (online) web currency converter sites. However for people like to use desktop applications like me it is much better to use a separate desktop tool which do currency convertion. If this is the case with and you happen to use Debian GNU / Linux, Ubuntu Fedora or any other main stream Linux distribution on your Linux powered Laptop or Tablet you will be surely happy to know about KEuroCalc – Universal Currency Converter. As all "K"-named starting Linux apps unfortunately keurocalc is using QT KDE graphic library and thus whenever used on GNOME it starts a bunch of KDE services (kedinit,klauncher, kded), however the load of this few on any modern notebook or PC is neglectably low so for most users the only disadvantage of kerocalc might be interface is looking a bit different compared to rest of Gnome GTK+ programs.

To install keurocalc on deb based Linuces e.g. – Debian / Ubuntu, ArchLinux ..:

noah:~# apt-cache show keurocalc|grep -i description -A 3

Description: universal currency converter and calculator – binary package
 KEurocalc is a universal currency converter and calculator.
 It downloads latest exchange rates directly from the
 European Central Bank and the Federal Reserve Bank of New York.

noah:~# apt-get install --yes keurocalc

Reading package lists… Done
Building dependency tree      
Reading state information… Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 23 not upgraded.
Need to get 0 B/87.8 kB of archives.
After this operation, 319 kB of additional disk space will be used.
Selecting previously deselected package keurocalc.
(Reading database … 393466 files and directories currently installed.)
Unpacking keurocalc (from …/keurocalc_1.0.3-2_amd64.deb) …
Processing triggers for hicolor-icon-theme …
Processing triggers for man-db …
Processing triggers for menu …
Processing triggers for gnome-menus …
Processing triggers for desktop-file-utils …
Setting up keurocalc (1.0.3-2) …
Processing triggers for menu …

On Fedora, CentOS and rest of RPM based Linux distros keurocalc is installable too out of default package repositories:

[root@fedora ~]# yum -y -q install keurocalc


Here is a snapshot of keurocalc GUI interface;

Linux Universal Currency Converter Keurocalc

Keurocalc Linux universal currency converter settings screenshot

As you see from settings screenshot, information about rates can be obtained from 2 sources; – European Central Bank and New York Federal Reserve Bank. I give a try also to Euro, no network access (fixed rates only) method but unfortunately by choosing it you can only convert between Fixed Currencies (currencies which are already not in use – in EU member states who dropped their local currencies in favor of EURO).

I've tested the program and it works good, the disadvantage is convertion between some of the World currencies of countries with non-transparent planned (Soviet like) economies for example Belarus is not among app list of convertable currencies.

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