bggen(l)bggen(l)NAMEbggen - generates colored backgrounds on X11 displays
SYNTAXbggen [-d display] [-g geometry] [-G rptgeom] [-r rot] [-a] [-w width]
[-h height] [-b bits] <color-spec> [<color-spec> ...]
DESCRIPTIONbggen is a program that generates a rectangular 24-bit image, with a
smooth vertical gradient between the listed colors. (If you only spec‐
ify one color, the image will be a single solid color.) The top of the
image will be in color (r1,g1,b1), and the bottom of the image will be
in color (rn,gn,bn). Intermediate positions in the image are interpo‐
lated between these colors. If you specify more than 2 colors, the
gradient passes through all the specified colors, in the order speci‐
The '-d' option lets you specify what display to connect to. bggen
only connects to the display to find out the size of the screen (and
hence, the default size for the generated image).
The '-g' option lets you control the size of the image, as a standard X
geometry specification. (ie, something like "512x348")
The '-G' option lets you control the tile size, as a standard X geome‐
try specification. (ie, something like "32x32") Normally, (if you
don't give a -G option), the gradient fills the entire image. If you
specify a -G option, the gradient will fill a portion of the image, and
that portion will be 'center-tiled' to fill the rest of the image.
The '-r' option lets you rotate the gradient counter-clockwise by the
specified number of degrees.
The '-a' option lets you force bggen to generate an image in PPM
'Ascii' format, rather than in PPM 'raw' format.
The '-w' and '-h' options also let you set the size of the image. They
are provided only for backward compatibility.
The '-b' option specifies the number of significant bits in the (out‐
put) color specifications. It must range between 1 and 8, inclusive.
Use values less than 8 (the default) to limit color use by increasing
the color granularity. Since XV can do this sort of thing better, this
is of dubious value.
A <color-spec> can be three integers separated by spaces, forming an
R,G,B triple ("0 255 0"). The values should be between 0 and 255.
A <color-spec> can also be a standard X color specification by name
("green") or value ("#00ff00"). This is decidedly easier, and the
'three integer' method remains mainly for backward compatibility. One
note: the '#' character is treated specially by many shells, and
should probably be protected by putting a '\' character in front of it,
or wrapping the entire value with a pair of single-quotes.
bggen doesn't actually affect your background directly. bggen merely
generates a PPM (Portable Pixmap Format) datafile and dumps it to 'std‐
out'. It's up to some other program (such as XV) to read this file and
To use bggen, you should pipe its output into an XV command, such as:
"xv -root -quit -"
Light Blue to Dark Blue
bggen 100 100 255 0 0 100 | xv -root -quit -
bggen red green blue | xv -root -quit -
bggen black green black -h 128 | xv -root -quit -
Blue to Magenta
bggen blue magenta | xv -root -quit -
bggen black red yellow green blue purple black | xv -root -quit -
bggen red yellow green blue purple red -h 256 | xv -root -quit -
bggen green black -r 30 -g 32x32 | xv -root -quit -
bggen red black -r 45 -g 32x32 | xv -root -quit -rmode 3 -
bggen red yellow -r 45 -g 32x32 | xv -root -quit -rmode 3 -
John Bradley - email@example.com