Some environment variables can be used to change the behaviour of libcaca without having to modify the program which uses it. These variables are:

• CACA_DRIVER: set the backend video driver. In order of preference:
  • conio uses the DOS conio.h interface.
  • ncurses uses the ncurses library.
  • slang uses the S-Lang library.
  • x11 uses the native X11 driver.
  • gl uses freeglut and opengl libraries.
  • raw outputs to the standard output instead of rendering the canvas. This is can be used together with cacaserver.

• CACA_GEOMETRY: set the video display size. The format of this variable must be XxY, with X and Y being integer values. This option currently works with the raw, X11 and GL drivers.

• CACA_FONT: set the rendered font. The format of this variable is implementation dependent, but since it currently only works with the X11 driver, an X11 font name such as fixed or 5x7 is expected.