Provided by: libsvga1-dev_1.4.3-31_i386 bug


       vga_safety_fork  - start a parallel process to restore the console at a


       #include <vga.h>

       void vga_safety_fork(void (*shutdown_routine)(void))


       Calling this at the start of a program results in a  better  chance  of
       textmode  being  restored  in case of a crash.  However it has to raise
       the iopl level to 3 to work. This is a small security breach as  it  is
       inherited  to any programs you fork of. However, some SVGA card drivers
       have to use iopl(3) anyway.  If you use it call that  function  as  the
       very first vga_ function. Call it right before vga_init (3).  Note that
       vga_safety_fork() will already enter  a  graphicsmode.  (For  font  and
       grafix  state  saving).  Don't overestimate the power of this function.
       Your application will continue to run in background while a  foreground
       application will restore a usable screen and graphics mode in case of a

       The    forktest(6)    demo    shows    the     principal     operation.
       (*shutdown_routine)()  is  called  when  the  system  crashes. However,
       realize that the call will take in  a  forked  copy  of  your  program,
       you'll   not   have   access   to   any   globals  modified  after  the
       vga_safety_fork() call!


       svgalib(7), vgagl(7), libvga.config(5), forktest(6), vga_init(3),


       This manual page was edited  by  Michael  Weller  <eowmob@exp-math.uni->.  The  exact  source of the referenced function as well as of
       the original documentation is unknown.

       It is very likely that both are at least to some extent are due to Harm
       Hanemaayer <>.

       Occasionally  this  might be wrong. I hereby asked to be excused by the
       original author and will happily accept any additions or corrections to
       this first version of the svgalib manual.