SETJMP(3)               GENIX Programmer's Manual               SETJMP(3)



      NAME
           setjmp, longjmp - non-local goto

      SYNOPSIS
           #include <setjmp.h>

           setjmp(env)
           jmp_buf env;

           longjmp(env, val)
           jmp_buf env;

      DESCRIPTION
           These routines are useful for dealing  with  errors  and  interrupts
           encountered in a low-level subroutine of a program.

           Setjmp saves its stack environment in env for later use by  longjmp.
           It returns value 0.

           Longjmp restores the environment saved by the last call  of  setjmp.
           It  then  returns  in  such a way that execution continues as if the
           call of setjmp had just returned the value val to the function  that
           invoked  setjmp, which must not itself have returned in the interim.
           All accessible data have values as of the time longjmp was called.

      SEE ALSO
           signal(2)

      BUGS
           For reasons of efficiency,  setjmp  and  longjmp  do  not  save  and
           restore  the  floating point registers.  Special forms of these rou-
           tines should be created which will save everything.























      Printed 11/16/83                                                        1