USAGE
   signed int scdnkprev(
           signed int handle,
           void *key,
           signed long *recno );

PROTOTYPE IN
   sc_base.h

DESCRIPTION
   scdnkprev will decrement the key pointer and return the key value
   key and data record number recno associated with the new current
   key.

   If scdnkprev is called immediately after opening the index file the
   last logical key will be returned.

NOTES
   The user must ensure that the buffer used to return the key is large
   enough to hold the entire key. The maximum length of the key can be
   determined via a call to scdninfo.

   Numeric keys are returned as doubles, and character keys are returned as
   strings.

EXAMPLE
   /*  Character Key Example  */
   #include <stdio.h>
   #include <softc.h>
   #include <sc_base.h>
   void main()
   {
     int ndx;
     char name[65];
     long recno;

     scdinit(20,0);
     if (scdnopenx(&ndx,"TOCNAME.NDX",SC_BUFFER) == SC_SUCCESS) {
       name[64] = 0;
       scdnkprev(ndx,name,&recno);    /* get last key */
       printf("%s %ld\n",name,recno);
       scdnclose(ndx);
     }
     scdterm();
   }

   /*  Numeric Key Example  */
   #include <stdio.h>
   #include <softc.h>
   #include <sc_base.h>

   void main()
   {
     int ndx;
     double length;
     long recno;

     scdinit(20,0);
     if (scdnopenx(&ndx,"TOCLNGTH.NDX",SC_BUFFER) == SC_SUCCESS) {
       scdnkprev(ndx,&length,&recno); /* get last key */
       printf("%lf %ld\n",length,recno);
       scdnclose(ndx);
     }
     scdterm();
   }