# How to know the type for VTU file

**URL:** https://discourse.vtk.org/t/how-to-know-the-type-for-vtu-file/13120
**Category:** Support
**Created:** [January 23, 2024, 5:16am UTC](https://discourse.vtk.org/t/how-to-know-the-type-for-vtu-file/13120 "2024-01-23T05:16:51Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Ludo](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/5f9b8f/32.png) [@Ludo](https://discourse.vtk.org/u/Ludo)
#### Post date: [January 23, 2024, 5:16am UTC](https://discourse.vtk.org/t/how-to-know-the-type-for-vtu-file/13120/1 "2024-01-23T05:16:51Z")

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Hello everyone,

So far I’ve used vtkDataReader class for vtk file in order to know if vtk file was Rectilineargrid,UnstructuredGrid or StructuredGrid by doing this test

```auto

vtkDataReader GlobalReader = vtkDataReader.New();
GlobalReader.SetFileName(VTKFilePath);
if (GlobalReader.IsFileRectilinearGrid() == 1)
{
//use vtkRectilinearGridReader
}
else if (GlobalReader.IsFileUnstructuredGrid() == 1)
{
//use vtkUnstructuredGridReader
}
else if (GlobalReader.IsFileStructuredGrid() == 1)
{
//use vtkStructuredGridReader
}

```

However vtkDataReader cannot be used for vtu file (unrecognized file type error raise)

Is there an equivalent of vtkDataReader for vtu file so I can know if I have to use vtkXMLUnstructuredGridReader, vtkXMLRectilinearGridReader or vtkXMLStructuredGridReader?

I really thank you in advance for your help

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<div class="post-metadata">

### Author: ![mwestphal](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mwestphal/32/19_2.png) [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [January 23, 2024, 8:18am UTC](https://discourse.vtk.org/t/how-to-know-the-type-for-vtu-file/13120/2 "2024-01-23T08:18:21Z")

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VTU stand for VTk Unstructured grid, no need to test anything.

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<div class="post-metadata">

### Author: ![Ludo](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/5f9b8f/32.png) [@Ludo](https://discourse.vtk.org/u/Ludo)
#### Post date: [January 23, 2024, 10:35pm UTC](https://discourse.vtk.org/t/how-to-know-the-type-for-vtu-file/13120/3 "2024-01-23T22:35:49Z")

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thank you very much for your help.