NAME

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

SYNOPSIS

       #include <vga.h>

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

DESCRIPTION

       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 crash.

       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!

SEE ALSO

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

AUTHOR

       This manual page was edited by Michael Weller <eowmob@exp-math.uni-essen.de>. 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
       <H.Hanemaayer@inter.nl.net>.

       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.

Svgalib (>= 1.2.11)                               27 July 1997                                vga_safety_fork(3)