tausta.ksh.sh

Korn Shell script, that change desktop wallpaper under X Window System

Contents

Pros and cons of this software

Pros

Main advantage of this software is extreme flexibility. Practically any command that can change your desktop wallpaper can be used by this software. This software tries to avoid loading wallpaper when XScreenSaver is running some of its screen hacks. You do not need Mad Shell-Fu Skillz for configuring this software.

Cons

If you do not want to change desktop wallpaper automatically after every few hours, this software is definitely not for you. If you want to change your desktop wallpaper after every few hours, but do not need all this flexibility, this software may be a little bit overkill for you. Some Bourne Shell -scripting skills are needed when configuring this software and for some people it is too much (but as I said before, you do not need Mad Shell-Fu Skillz)

Notes

In my machine a command called ps is from software package called procps. If you use some GNU/Linux-distribution, you probably have it. I have not tested, how well these scripts work with other implementations of ps-command.

tausta.sh script is written in plain Bourne Shell -language; It is not as reliable as tausta.ksh.sh : I have seen many times, that tausta.sh scripts loads wallpaper when xscreensaver runs some screen hack. If you experience same problem, install some implementation of Korn Shell -language (ie. pdksh, mksh or zsh) and use tausta.ksh.sh instead.

Most proprietary Unixes has at least AT&T ksh88. Some of them has dtksh; It is ksh93 with CDE-capabilities. pdksh has tinier binary than zsh, so you’d better use it as implementation of Korn Shell-language. pdksh is full of bugs, but those bugs should not affect using this software. There is also so called mksh; it is based on source code of pdksh, but its authors has fixed its bugs. If you use zsh as Korn Shell-implamentation, you must make it emulate ksh with this command:

emulate ksh

The Original AT&T KSH93 is finally really free software, so feel free to use it:

http://www.kornshell.com/

At least Debian GNU/Linux and Slackware Linux have it packaged already.

It seems, this script is most reliable, when you use the original AT&T KSH93 as your Korn Shell -implementation.

Installation

First you need some cool software, that can load wallpaper or image to X Window System desktop. I prefer xli and hsetroot. If I want to download some frequently updated image from WWW and load it as wallpaper, I prefer dog for that purpose, but curl is also good.

Create directory ~/.tausta.sh.dir . tausta.rc.sh has some user-serviceable parts you can edit; at least name of window manager process must be right or script won’t run at all. Put tausta.rc.sh to ~/.tausta.sh.dir/ . Put scripts tausta.sh and tausta.ksh.sh to some directory in your $PATH , for example ~/bin/ . You may need to edit them a little bit, first. Use chmod-command to ensure that you can run them.

Now create some file called tausta.conf and put it to ~/tausta.sh.dir . A file called tausta.conf is provided as example. Empty lines and lines starting with # are ignored, of course. Commands are normal commands that Bourne Shell or any of its derivative understands. You can use exported environment variables instead of plain commands and directory paths. Those environment variables are exported in file ~/tausta.sh.dir/tausta.rc.sh .

You can unsort lines of tausta.conf with software like rl , unsort or bogosort.

Now everything should be in place. Then you must configure your X-session, windowmanager or desktop environment so, that command like this is run automatically during startup:

nice -n 20 tausta.ksh.sh &

If your computer is powerfull enough, you can omit that nice -n 20, of course.

You can stop waiting for next loading of wallpaper with commands like these:

kill -USR1 $(cat ~/.tausta.sh.dir/tausta.pid)
kill -USR1 `cat ~/.tausta.sh.dir/tausta.pid`

Feel free to bind them to some menu entry, panel button, keybinding etc. After giving such command, you must wait about amount of $CHECKINTERVAL seconds before the next wallpaper is loaded.

Use signal like 1, 2, 3, 15 or 20 (SIGHUP, SIGINT, SIGQUIT, SIGTERM or SIGCHLD) to stop script, so it can safely exit. You can restart script with signal USR2 .

If some image loading command makes your desktop background messed up, or any other anomalies are seen, then check out file ~/.tausta.sh.dir/lastcommand to find out which command was tried when loading the latest image. That file is also usefull, if you think that latest loaded wallpaper is boring and you want to remove it from configuration files.

Please, remember that command killall sleep is not a good way to stop waiting for the next image-loading command: At least in AT&T KSH93 sleep is a builtin command.

Commands for loading wallpapers

Software

Consult these, if you can’t find some software:

For loading wallpapers

For loading desktop wallpaper from many files

For making (random) pics (on the root window)

For unsorting lines of tausta.conf

You’d better learn this feature of your text editor: How to pipe chosen lines of text to external command and then substitute those lines with output of that command. If your text editor can’t do it, it’s time to learn some better text editor, like vi, Vim, GNU Emacs, XEmacs or SXEmacs. Learn to use “undo”, too.

For fetching files from WWW

  • dog. (This is probably the fastest software for this purpose, becuse it has the smallest binary. But it has been reported to have ugly source code. This program can not handle redirection at all. Hence, it needs direct URL.)
  • snarf. (Has smaller binary than curl. In fact it is just a little bit bigger than binary of dog. Very recommended.)
  • curl. (Much smaller binary than in wget. Available in most Linux-distributions and very commonly found in many Unix-workstations. Very recommended; oriented towards downloading just one file.)
  • wget. (Available in most Linux-distributions. Not too bad, but oriented towards downloading whole directories or other bigger entities. Has bigger binary than curl.)
  • lynx. (This is really a WWW-browser)
  • w3m. (This is really a WWW-browser)
  • links/elinks/links2/links hacked/whatever. (These are really a WWW-browsers. Argh… I do not bother tell homepages of all those forks. Use Google and Wikipedia.)

Commands

Especially I tell you how to substitute xv-commands with free software.

Beginning of commands

xv -smooth +noresetroot -root -quit
xli -quiet -cdither -onroot

Tiled

xv -smooth +noresetroot -root -quit /usr/local/textures/3com01.jpg
xli -quiet -cdither -onroot /usr/local/textures/3com01.jpg

Center tiled

xv -smooth +noresetroot -root -rmode 4 -quit \
/usr/local/textures/applix01.jpg
hsetroot -tile /usr/local/textures/applix01.jpg
chbg -mode centertile /usr/local/textures/applix01.jpg

Centered

xv -smooth +noresetroot -root -rmode 5 -quit \
/usr/local/textures/stickdeath01.jpg
xli -quiet -cdither -onroot -center -border black \
/usr/local/textures/stickdeath01.jpg
hsetroot -center /usr/local/textures/stickdeath01.jpg

Maximized

Stretch image to fill whole screen:

xv -smooth +noresetroot -root -max -quit \
/usr/local/textures/soundbla.jpg
hsetroot -fill /usr/local/textures/soundbla.jpg
xli -quiet -cdither -onroot -fillscreen -border black \
-smooth /usr/local/textures/soundbla.jpg

Stretch image, but keep aspect ratio:

hsetroot -full /usr/local/textures/soundbla.jpg
xli -quiet -cdither -onroot -fullscreen -border black \
-smooth /usr/local/textures/soundbla.jpg

Often updated WWW-image

(Don’t blame me, if such image is one day replaced with goatse or tubgirl or if some goatse-like guy starts doing his thing in front of some webcam…) dog can not handle redirection. hsetroot can not read from stdin.

dog --no-header http://vision.ucsd.edu/~atai/softwarewar.png \
| xsetbg -quiet -onroot -center stdin
dog --no-header http://www.ssec.wisc.edu/data/comp/latest_moll.gif \
| xsetbg -quiet -onroot -fullscreen stdin
dog --no-header http://www.ssec.wisc.edu/data/comp/latest_moll.gif \
| xli -quiet -cdither -onroot -fullscreen -border black -smooth \
stdin
snarf http://www.ssec.wisc.edu/data/comp/latest_moll.gif - \
| xsetbg -quiet -onroot -fullscreen stdin
curl -s http://vision.ucsd.edu/~atai/softwarewar.png \
| xsetbg -quiet -onroot stdin
wget -q -O - http://vision.ucsd.edu/~atai/softwarewar.png \
| xsetbg -quiet -onroot -center stdin
lynx --source --dump http://vision.ucsd.edu/~atai/softwarewar.png \
| xsetbg -quiet -onroot -center stdin
elinks -dump -source  http://iki.fi/juhtolv/pix/ryppy_black.jpg \
| xsetbg -quiet -onroot stdin
w3m -dump_source http://iki.fi/juhtolv/pix/ryppy.jpg \
| xsetbg -quiet -onroot stdin

Phase of the moon etc.

xphoon
xplanet -config ~/.xplanet/config -longitude 25.5 -latitude \
62.1 -label -num_times 1 -label_string "Origin: %o. Target:  %t." \
-labelpos "+15+15" -pango -font 'Sans' -fontsize 12
xplanet -config ~/.xplanet/config -longitude 25.5 -label \
-num_times 1 -label_string "Origin: %o. Target:  %t." \
-labelpos "+15+15" -pango -font 'Sans' -fontsize 12 -projection \
mercator
xplanet -config ~/.xplanet/config -longitude 25.5 -label \
-num_times 1 -label_string "Origin: %o. Target:  %t." -labelpos \
"+15+15" -pango -font 'Sans' -fontsize 12 -projection lambert
xplanet -config ~/.xplanet/config -latitude 90 -label \
-num_times 1 -label_string "Origin: %o. Target:  %t." -labelpos \
"+15+15" -pango -font 'Sans' -fontsize 12 -projection azimuthal
xplanet -config ~/.xplanet/config -latitude -90 -label -num_times \
1 -label_string "Origin: %o. Target:  %t." -labelpos "+15+15" \
-pango -font 'Sans' -fontsize 12 -projection azimuthal
xplanet -config ~/.xplanet/config -longitude 25.5 -label \
-num_times 1 -label_string "Origin: %o. Target:  %t." -labelpos \
"+15+15" -pango -font 'Sans' -fontsize 12 -projection ancient
xplanet -config ~/.xplanet/config -longitude 25.5 -label \
-num_times 1 -label_string "Origin: %o. Target:  %t." -labelpos \
"+15+15" -pango -font 'Sans' -fontsize 12 -projection hemisphere
xplanet -config ~/.xplanet/config -longitude 25.5 -latitude \
62.1 -label -num_times 1 -label_string "Origin: %o. Target:  %t." \
-labelpos "+15+15" -pango -font 'Sans' -fontsize 12 -projection \
orthographic

Randomly generated pic

xstarfish --size random
xstarfish --size small
xstarfish --size medium
xstarfish --size large
xstarfish --size full

Doing it in Gnome way

Set background image:

gconftool --type string --set \
/desktop/gnome/background/picture_filename \
/path/to/filename

Image options (yes, separated command):

# Fill screen. Keep aspect ratio (in Gnome 2.16):
gconftool --type string --set \
/desktop/gnome/background/picture_options scaled

As I am writing this, that part picture_options can have one of these values:

  • none
  • wallpaper
  • centered
  • scaled
  • stretched

You can check out which image options are available by doing this: Start up a program called gconf-editor. See gconf-option /desktop/gnome/background/ .

Known bugs

If this script get signal USR1 too often, process of this script seems to spawn more copies of itself. Workaround: After you have sent that signal, do not send it again too soon. Instead, wait until new wallpaper is really loaded AND after that wait until at least $CHECK_INTERVAL seconds of time has run.

That file ~/.tausta.sh.dir/tausta.pid may go out of sync.

About this document

This document is originally written in lightweight markup language called “reStructuredText”. It is in a file called README.txt. If you want to edit it and then re-generate other formats of this document, you must install software called python-docutils. Bourne Shell -script called compileall.sh generates HTML-, TeX-, PostScript-, and PDF-version of this file. HTML-version is ready for any WWW-browser. TeX-version is compiled with pdflatex to PDF-version. You’d better have quite decent TeX-distribution, or that LaTeX-compilation will fail. I use TeX Live. Then PDF-version is converted to PostScript with pdftops (belongs to XPDF).