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

PROTOTYPE IN
   sc_base.h

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

   If scdcknext is called immediately after opening the index file the
   first 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 scdcinfo.

   All keys are returned as strings.

EXAMPLE
   #include <stdio.h>
   #include <softc.h>
   #include <sc_base.h>

   void main()
   {
     int ntx;
     char key[11];
     long recno;

     scdinit(20,0);
     if (scdcopenx(&ntx, "TOCLNGTH.NTX", SC_BUFFER) == SC_SUCCESS) {
       scdcknext(ntx,key,&recno);     /* return first key */
       printf("%s %ld\n",key,recno);
       scdcclose(ntx);
     }
     scdterm();
   }