_NameTableIndex( ) API Library Routine

Visual FoxPro 9.0 SP2

_NameTableIndex( ) API Library Routine


NTI _NameTableIndex(char FAR name) char FAR name; /* Name. */

Remarks

The name may be found in the name table even though a variable with the name name doesn't exist. To determine whether a variable with the name name exists, use _FindVar( ), specifying the name table index returned by _NameTableIndex( ) as the nti parameter.

For more information on how to create an API library and integrate it with Visual FoxPro, see Accessing the Visual FoxPro API.

Example

The following example releases a memory variable whose name is given as a character argument. Note that _NameTableIndex( ) finds the variable name after it has been released. Therefore, _NameTableIndex( ) is used in combination with _FindVar( ) to make sure the memory variable is currently defined.

Visual FoxPro Code

	Copy Code
SET LIBRARY TO NTI x = 123 = XRELEASE("x")

C Code

	Copy Code
#include <pro_ext.h> FAR ReleaseEx(ParamBlk FAR parm) { NTI nti; char FAR name; int exitCode; Locator loc; // Null terminate character string, name of variable if (!_SetHandSize(parm->p[0].val.ev_handle, parm->p[0].val.ev_length+1)) { _Error(182); // "Insufficient memory" } _HLock(parm->p[0].val.ev_handle); name = (char FAR ) _HandToPtr(parm->p[0].val.ev_handle); name[parm->p[0].val.ev_length] = '\0'; if ((nti = _NameTableIndex(name)) == -1) { _HUnLock(parm->p[0].val.ev_handle); _UserError("Cannot find variable in name table."); } _HUnLock(parm->p[0].val.ev_handle); if (_FindVar(nti, -1, &loc)) { _PutStr("\nVariable exists prior to _Release()."); } if ((exitCode =_Release(nti)) < 0) { _Error(-exitCode); } _HLock(parm->p[0].val.ev_handle); name = (char FAR ) _HandToPtr(parm->p[0].val.ev_handle); name[parm->p[0].val.ev_length] = '\0'; if ((nti = _NameTableIndex(name)) != -1) { _PutStr("\n_NameTableIndex() still finds variable \ after it is released."); } _HUnLock(parm->p[0].val.ev_handle); if (!_FindVar(nti, -1, &loc)) { _PutStr("\nVariable does not exist after _Release()."); } } FoxInfo myFoxInfo[] = { {"XRELEASE", (FPFI) ReleaseEx, 1, "C"}, }; FoxTable _FoxTable = { (FoxTable FAR *) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo };

Copy Code

#include <pro_ext.h>
FAR ReleaseEx(ParamBlk FAR *parm)
{
   NTI nti;
   char FAR *name;
   int exitCode;
   Locator loc;
   //   Null terminate character string, name of variable
   if (!_SetHandSize(parm->p[0].val.ev_handle,
      parm->p[0].val.ev_length+1))
   {
      _Error(182); // "Insufficient memory"
   }
   _HLock(parm->p[0].val.ev_handle);
   name = (char FAR *) _HandToPtr(parm->p[0].val.ev_handle);
   name[parm->p[0].val.ev_length] = '\0';
   if ((nti = _NameTableIndex(name)) == -1)
   {
      _HUnLock(parm->p[0].val.ev_handle);
      _UserError("Cannot find variable in name table.");
   }
   _HUnLock(parm->p[0].val.ev_handle);
   if (_FindVar(nti, -1, &loc))
   {
      _PutStr("\nVariable exists prior to _Release().");
   }
   if ((exitCode =_Release(nti)) < 0)
   {
      _Error(-exitCode);
   }
   _HLock(parm->p[0].val.ev_handle);
   name = (char FAR *) _HandToPtr(parm->p[0].val.ev_handle);
   name[parm->p[0].val.ev_length] = '\0';
   if ((nti = _NameTableIndex(name)) != -1)
   {
      _PutStr("\n_NameTableIndex() still finds variable \
         after it is released.");
   }
   _HUnLock(parm->p[0].val.ev_handle);
   if (!_FindVar(nti, -1, &loc))
   {
      _PutStr("\nVariable does not exist after _Release().");
   }
}
FoxInfo myFoxInfo[] = {
   {"XRELEASE", (FPFI) ReleaseEx, 1, "C"},
};
FoxTable _FoxTable = {
   (FoxTable FAR *) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo
};

_NameTableIndex( ) API Library Routine

Remarks

Example

Visual FoxPro Code

C Code

See Also

Reference

Concepts

Other Resources