ZUFALL(1)

NAME
zufall - a simple program to change the background periodically.

SYNOPSIS
zufall [options] /path/to/imagedir-or-file [/path/to/imagedir-or-file]

DESCRIPTION
zufall takes one or more directories with images as a parameter and sets a randomly chosen image as background. If there is a border remaining, its color is the average color of two corners of the image. This mostly fits the image very well. It is also possible to execute a command when the image changes.

zufall does not work if the root window is hidden by another program that does not pick up changes on the root window.

OPTIONS

-d, --delay=delay
    number of seconds an image is shown (default 900)

-s  --maxscale=percent
    maximum percent the image will be scaled (default 150)

-b  --minborder=pixel
    ignore --maxscale if the remaining border would be smaller than pixel (default 100)

-m  --minsize=kilobyte
    only show images bigger than kilobyte. A size of 0 shows all images (default 0)

-l  --list=file
    load list of images from file

    • the format of the file is one directory or file per line

    • file can also be a collection from gqview

    • if file is -, the list will be read from stdin

-S  --sequential
    don't randomize the imagelist. This is useful with -l, or if you want to see the images directory-wise.

-c  --command=command
    execute command on every picture change. Within command

    %c  gets replaced with the background-color

    %i  gets replaced with the image-filename

    %w  gets replaced with the scaled width

    %h  gets replaced with the scaled height

    %%  gets replaced with %

    Mind the quoting, the command is interpreted by the shell!

-n  --no-set
    don't set the background (but execute command if given)

-p  --passes=passes
    exit after given number of images

--help
    display help and exit

--version
    output version information and exit

SIGNALS

HUP change background

USR1
    output some info. Note that the memory shown is only the memory that is used for the paths. There is additional memory used by the X-server to hold the image.

TERM
    exit

GNOME
zufall can not be used directly to set the background in gnome. This is because nautilus covers the root window, so the background can not be seen. Additionally nautilus will crash.

To randomize the background in Gnome, the wrapper script zufall-gnome exists, which uses gconftool-2 to set the background. It takes the same parameters as zufall. Note that the parameters affecting the size of the background image will not work when using zufall-gnome.

XFCE
If zufall is started within Xfce, xfdesktop will give up the desktop completely (including desktop menus), but no background image will be shown. However, Xfce is able to change to a random background that it gets from a file by itself. With this mechanism zufall could be used to manage the picture changes, but there seems to be no good solution to set the desktop color and size of the image with zufall.

EXAMPLES
To try out what the -c option does:

zufall /path/to/images -n -c 'echo “picture: %i color: %c scaled res: %wx%h“'

To append the name of the current image to a file:

zufall /path/to/images -c 'echo “%i“ >> /tmp/imagehistory'

To view random images in gqview:

zufall /path/to/images -n -c 'gqview -r “%i“'

To get a list of files from another program (GNU-find in this case)

find /path/to/images -type f -size +512k -not -wholename '/path/to/bad/images/*' | zufall -l -

TIP
Bind pkill -1 zufall to a key or put it in a launcher to change the background with a keypress.

BUGS

How portable is it? Please tell me if you can('t) get it to run under anything else than GNU/Linux or FreeBSD!

Please send bug reports and feedback to the author.

SEE ALSO
gqview(1) gconftool-2(1)

AUTHOR
Moritz Orbach <zufall@apfelboymchen.homeunix.net>