/* i4key.c   (c)Copyright Sequiter Software Inc., 1990-1994.  All rights reserved. */

#include "d4all.h"
#ifndef S4UNIX
#ifdef __TURBOC__
#pragma hdrstop
#endif
#endif

#ifndef S4INDEX_OFF

char S4PTR *S4FUNCTION t4key( TAG4 S4PTR *t4 )
{
  B4BLOCK *b4 ;

#ifdef S4VBASIC
  if ( c4parm_check( t4->code_base, 1, "t4key():" ) ) return 0 ;
#endif

#ifdef S4DEBUG
  if ( t4 == 0 )
    e4severe( e4parm, E4_T4KEY ) ;
#endif

  if ( t4->code_base->error_code < 0 )
    return 0 ;

  b4 = (B4BLOCK *)(t4->blocks.last_node) ;

  if ( b4 == 0 )
    return 0 ;

#ifdef S4FOX
  if ( b4->key_on >=  b4->header.n_keys )  /* eof */
#else
    if ( b4->key_on >= b4->n_keys )  /* eof */
#endif
      return 0 ;

  return (char *)b4key_key( b4, b4->key_on ) ;
}

#endif

#ifdef S4VB_DOS

char * t4key_v( TAG4 *t4 )
{
  int len ;
  char *key ;

#ifdef S4VBASIC
  if ( c4parm_check( t4->code_base, 1, "t4key():" ) ) return 0 ;
#endif

  StringRelease( basic_desc );

  if( ! (key = t4key(t4)) )
    return basic_desc ;

  StringAssign( key, expr4key_len(t4->expr), basic_desc, 0 );

  return basic_desc ;

}

#endif