Debian Package of the Day (static archived copy)

Article submitted by Nigel Barker. And guess what? We still need you to submit good articles about software you like!

View Your Mind is a graphical mind mapping tool, which can be used for brainstorming, planning, drafting, gathering resources; or as a quick way to convert ideas into a web page or Open Office presentation. The UI is intuitive and takes almost no time to learn. When you open the program you are presented with a blank map with a yellow starting box already selected for your central idea.

Then by clicking the branch tool you begin to add further thoughts and sub-levels. If an idea is too big to fit on the page (though there is no limit and you can zoom, scroll or link to a new map), then there is also a built in rich text editor where you can type longer entries. A set of emoticons are available for those who like to label their thoughts - good for brainstorming.

Images can also be attached to branches, and later saved back out of the map into an image file. However, if an image is large it will not be scaled and you will struggle to scroll around your map. Also the saved images don’t open for me - something buggy here? Branches can be made into URLs, which launch your default browser when clicked, and also work later when you export the map.

When you have finished jotting down your thoughts or writing your draft, then it is time to export. Several interesting options are available, and this is what makes vym really useful for me. The map doesn’t have to be the end product - it can be just the beginning. You can hide branches that you don’t want to export, then choose from a list that includes a web page (with an image map linking to all the text editor notes you wrote (anchored further down the page), and external links from branches you added as URLs), ascii text which contains just enough structure to enable easy formatting in a word processor, an Open Office presentation (large amounts of text won’t fit, but good for simple bullet point slides), and other options I haven’t tried such as LaTeX and csv.

Vym can import maps from Freemind, another GPL mind mapper, and from Mindmanager, a commercial product. To be honest I haven’t used Freemind, but I like the way branches can be dragged around in vym, and re-ordered by dropping them on parent nodes, which doesn’t seem to work in Freemind. I use vym with my kids at school, because it is very useful but easy to learn. Freemind looks as though you have to spend some time finding out how it works.

Vym is available in Debian since Etch (Sarge via backports) and Ubuntu since Dapper.

Vym is maintained by its author Uwe Drechsel, and is available in English and German.

Project homepage: http://www.insilmaril.de/vym/

Article submitted by Nicolas Brailovsky. And guess what? We still need you to submit good articles about software you like!

Did you ever get to struggle against your text editor’s random format feature while trying to write a document? Open Office may be a great project, but when you want to focus on the content, it can be annoying to have your editor format or unformat your text, seemingly at random.

Well there are good news for those of us using Vim to create content and then Abiword to format it: LyX is a text editor that produces beautiful documents, without the need of being a designer, and yet manages to stay out of the way. From the tutorial and the homepage (www.lyx.org):

LyX is the first WYSIWYM (What You See Is What You Mean) document processor. The basic idea of LyX is that you do not need to handle style, or actually, you use a set of predefined styles and concentrate on your document content, This makes sure that your resulting document will be typographically correct and good looking visually. [...] LyX uses Latex as its back end typesetting mechanism.

Sounds great already, doesn’t it?

A first look into LyX

Upon start LyX looks more or less like any other graphical text editor in the universe:

Well, it’s logo may look nicer, but that’s about it. Anyway, the magic starts just as you start writing: you’ll notice most of the common format options seems missing, but you can define what you’re writing instead:

Note that we don’t tell it to center it or to make the font larger and bold. LyX takes care of all that automatically. Simply click on the format menu (below File, and it has the default value of “Standard”).

So instead of defining Times New Roman 12px bold centered, you say «Title». WYSIWYM, remember? In the homepage there is a «Graphical Tour» with all the basic functions, it’s quick and it’s great: www.lyx.org/LGT

Some useful features

LyX also provides a great support for math formulas (and all the weird symbols you can think off). Just click the button «Insert Equation» and a box to enter math symbols will appear. No more struggle to align the dividend and the divisor!

Of course, LyX provides the usual features such as tables, spell checking, footnotes and many more. The tutorial of the application is more than complete, and easy to follow.

LyX documents formats

LyX documents can be exported to a wide variety of formats, mainly because being based on Latex it takes advantage of the already existing conversion programs. Some of the possible export plugins installed by default are PS, PDF, DVI, Latex, HTML and Plain text, but custom ones may be defined.

What LyX isn’t for

Although LyX may be a valuable piece in anyone toolkit it’s worth noticing it isn’t exactly the Swiss army knife of the text editors. If you need to define a very customized layout or format, like slides for a presentation, this is the wrong tool for the job.

Availability

According to it’s homepage, LyX 1.5.3 was released the 16 th of December, 2007. It’s available in Debian since Sarge (packages.debian.org/LyX). Lyx Version 1.5.1, released 4 th of August, 2007, is available in the repository of Ubuntu 7.10. Development is still active. There’s also a Windows version for those of us stuck with primitive a OS at work.

Article submitted by Carles Pina from Catux-LUG. And guess what? We still need you to submit good articles about software you like!

There are many occasions at which a user needs to use two computers at the same time, even with two different operating systems, all in the same desktop. One of the most annoying things that might happen is that you will need to use a different set of keyboard and mouse for each computer with the resulting waste of space on your table.

One of the first solutions that firstly came to mind was to use only one set of keyboard and mouse to access the other computer through some kind of terminal software such as VNC, ssh, FreeNX,… but, sometimes we would prefer to really use the other computer, providing us with access to two real screens (very comfortable), for graphical design tasks, games, closer feeling to the user interface, etc. This is the case we are going to talk about.

What is synergy?

Synergy is a multi-platform client-server program designed to share the same keyboard and mouse for different computers connected by network.

How do yo use it? (in other words, how to change from one computer to the other): The basic usage consists of just moving the mouse pointer from one screen to another, though it also includes some kind of protection for those cases when the pointer is at the corner of the screen for other purposes like closing a window using the x at the top-right. Nevertheless, the option to configure a keyboard shortcut to move between screens is given.

Configuration

The configuration is pretty straightforward: you need to define the screens’ layout (which screen is situated on the right, left, top, bottom).

For example, if we had two computers, one called “desktop” and the other one “laptop”, and we wanted to use the keyboard from desktop (then desktop will act as the server), we need to write the following configuration file in /etc/synergy.conf, or any location if we started synergys with the --config PATH_TO_CONFIG flag.

section: screens
        desktop:
        laptop:
end

section: links
desktop:
        right = laptop
laptop:
        left = desktop
end

Computer names are the same name the hostname command reports.

Then, in the computer that acts as server we will execute, to read the configuration from /etc:

$ synergys

Or, to read the config from our home directory:

$ synergys --config ~/.synergy.conf 

And then, in each client computer:

$ synergyc SERVER_IP

If we have problems, we can track them using:

$ synergyc -f SERVER_IP

Information

In the project’s webpage you can find very good documentation.

Please note that synergy doesn’t offer secure connections yet, but we can use any VPN or SSH tunnel to avoid our sessions being captured in the network. See the security page in the project’s website.

Also check the quicksynergy package, which is a graphic user interface for synergy.

Synergy has been available at the Debian and Ubuntu repositories since long ago.

Thanks a lot to Fran Hermoso for the extensive text correction and improvement and to Peral for showing me synergy.

Article submitted by Adrian von Bidder. And guess what? We still need you to submit good articles about software you like!

The psmisc package is probably installed on almost all Debian and Ubuntu installations and contains a number of small tools related to process management on Unix systems. Namely, these are pstree, killall, fuser and peekfd. Below follows a short description of these useful tools. While everybody certainly knows killall and probably pstree, the package also contains fuser and peekfd, which were new to me until very recently (though I hear at least fuser is an age-old tool. Shame on me.)

killall is exactly as evil as it sounds: it kills all processes with a given name. SIGTERM is used by default, but it can of course use any other signal. It also has options to match processes by user, by a specified regex or by process group. I usually use it to shoot parts of KDE with invocations like:

$ killall kio_imap4

Since kmail seems to have something of a troubled relationship with my IMAP server. (As an aside, I’d also like to point out the program slay, packaged in the slay package, which simply kills all processes belonging to a specified user.)

A nice overview on what is running on a system is the output of pstree. Part of the output on my system is:

$ pstree
init─┬─NetworkManager───2*[{NetworkManager}]
     ├─NetworkManagerD
     ├─acpid
     ├─hald───hald-runner─┬─hald-addon-acpi
     │                    ├─hald-addon-cpuf
     │                    ├─hald-addon-dell
     │                    ├─hald-addon-inpu
     │                    └─hald-addon-stor
     ├─kdeinit─┬─artsd
     │         ├─2*[kio_file]
     │         ├─kio_http
     │         ├─3*[kio_imap4]
     │         ├─kioexec───wfica.sh───wfica
     │         ├─klauncher
     │         ├─konqueror
     │         ├─konsole───bash─┬─pstree
     │         │                └─xchat───{xchat}
     │         └─kwin
     ├─kdesktop───lineakd───2*[{lineakd}]
     ├─kdm─┬─Xorg
     │     └─kdm───startkde───kwrapper
     └─sshd

Options to pstree include display of PIDs, users and SE-Linux contexts.

fuser lets you find out what processes use a certain file, for example:

$ fuser -v /home/avbidder/.xsession-errors
                    USER        PID ACCESS COMMAND
/home/avbidder/.xsession-errors:
                    avbidder   4409 F.... startkde
                    avbidder   4533 F.... kdeinit
                    avbidder   4536 F.... dcopserver
                    avbidder   4538 F.... klauncher
                    avbidder   4540 F.... kded
                    avbidder   4547 F.... kwrapper
                    avbidder   4549 F.... ksmserver
                    avbidder   4550 F.... kwin
                    avbidder   4552 F.... kdesktop
                    avbidder   4554 F.... kicker
                    avbidder   4562 F.... artsd
                    avbidder   4567 F.... kmix
                    avbidder   4568 F.... konsole
                    avbidder   4572 F.... beagled
                    avbidder   4574 F.... lineakd
                    avbidder   4579 F.... knetworkmanager
                    avbidder   4680 F.... knotify
                    avbidder   4916 F.... kio_uiserver
                    avbidder   5706 F.... akregator
                    avbidder   5708 F.... kttsd
                    avbidder   5742 F.... kio_file
                    avbidder   5864 F.... beagled-helper
                    avbidder   6939 F.... konqueror
                    avbidder   7076 F.... konqueror
                    avbidder   7185 F.... kmail
                    avbidder   7696 F.... kio_imap4

fuser also has options to send signals to these programs, so you can easily KILL all these programs with fuser -k /home/avbidder/.xsession-errors (this uses SIGKILL by default, but of course you can change this.)

While fuser is a regular system administrator’s tool, peekfd is a real deep-diver: it lets you watch what goes on on a filedescriptor of a process. (Please note that peekfd is not available in etch, you need psmisc from Lenny or newer.)

If you type peekfd <pid> at a terminal, it will follow all file descriptors of the process, to get an output like this:

$ peekfd 7808

writing fd 1:
foo bar

Where 7808 is just cat >/dev/null in another terminal window, with me typing “foo bar” in it. The manual page warns about it killing the monitored process (which I haven’t seen so far) and I’ve had peekfd segfault on me a few times, so I guess there’s some real ugly magic going on behind the scenes.

Instead of following all input and output of a process, by specifying the file descriptor number, you can follow only a selection of the files a process has opened. The directory /proc/<pid>/fd is a good way to find out which file descriptors might be worth looking at.

So let this article be a motivation to have a closer look at all the packages that you’ve installed on your system since at least potato and haven’t really looked at lately…

Article submitted by arno. We are running out of articles! Please help DPOTD and submit good articles about software you like!

colordiff is a small tool to colorize diff output which greatly improves readability.

colordiff can be used as a wrapper around diff, a tool used to compare files line by line. Simply run:

$ colordiff file1 file2

That will output differences between file1 and file2 in a colored way. You can also pass diff options to colordiff. So, to output a colored difference between two directories, you can run:

$ colordiff -Nur dir1 dir2

colordiff can also be used through a pipe. Just give it some diff content on its input and it will output the same content with colors.

$ cat some_patch_file | colordiff

Or:

$ cvs diff | colordiff

colordiff even works with wdiff since version 1.0.7 (currently only in Debian unstable, not in Ubuntu).

Default colors are very clean on a dark terminal: blue for new text, red for old text, magenta for other diff stuff. You can also modify them easily if you wish. Because colordiff has no way to determine if it writes on a dark or on a light terminal, default colors may be quite harsh on a white terminal. So, colordiff comes with colordiffrc-lightbg file, a configuration example for light backgrounds.

Related tools

Many text editors can display differences with two or more files. Graphical tool xxdiff can display differences between two or three files (it also has more features).

If you like to colorize everything on the console, you may like ccze to colorize log files, colormake to colorize make output, colorgcc to colorize gcc output, or highlight (with --ansi option) to colorize source code for more than 100 languages.

Tips

diff alias

Colordiff can be used anywhere diff is used. So, you may want to set colordiff as an alias for diff. Put in your shell configuration file:

alias diff=colordiff

svndiff function

If you use version control regularly, it may be useful to define a diff wrapper in your ~/.bashrc, ~/.zshrc, or other shell configuration file. For example, here is my svndiff function:

svndiff () { svn diff "${@}" | colordiff | less -R -E }

So, I can run svndiff in a directory controlled by svn, and get very readable differences information. You can find a cvsdiff function in colordiff manual, or write one for your favorite control version.

Screenshots

You can find some screenshots on colordiff site:
http://colordiff.sourceforge.net/screenshots.html

colordiff is available in Debian from oldstable Sarge to unstable Sid and for Ubuntu from Dapper to Gutsy.