TRAPER(3F)                                                          TRAPER(3F)



NAME
       traper - trap arithmetic errors

SYNOPSIS
       integer function traper (mask)

DESCRIPTION
       NOTE:  This  routine  applies  only  to  the VAX.  It is ignored on the
       PDP11.

       Integer overflow and floating point underflow are not normally  trapped
       during  execution.  This  routine enables these traps by setting status
       bits in the process status word. These bits are reset  on  entry  to  a
       subprogram,  and  the previous state is restored on return.  Therefore,
       this routine must be called _i_n_s_i_d_e each subprogram in which these  con‐
       ditions  should  be  trapped.   If the condition occurs and trapping is
       enabled, signal SIGFPE is sent to the process. (See _s_i_g_n_a_l(3C))

       The argument has the following meaning:

               value   meaning
                 0     do not trap either condition
                 1     trap integer overflow only
                 2     trap floating underflow only
                 3     trap both the above

       The previous value of these bits is returned.

FILES
       /usr/lib/libF77.a

SEE ALSO
       signal(3C), signal(3F)



4.2 Berkeley Distribution        May 15, 1985                       TRAPER(3F)