# PetscViewerBinaryGetDescriptor

Extracts the file descriptor from a PetscViewer.

### Synopsis

    #include "petsc.h"
    PetscErrorCode PETSC_DLLEXPORT PetscViewerBinaryGetDescriptor(PetscViewer viewer,int *fdes)

Not Collective

| viewer | - PetscViewer context, obtained from PetscViewerBinaryOpen()
| fdes | - file descriptor

### Notes

For writable binary PetscViewers, the descriptor will only be valid for the first processor in the communicator that shares the PetscViewer. For readable files it will only be valid on nodes that have the file. If node 0 does not have the file it generates an error even if another node does have the file.

### Fortran Note

This routine is not supported in Fortran.

### See Also

PetscViewerBinaryOpen(),PetscViewerBinaryGetInfoPointer()

Level:advanced
Location:src/sys/src/viewer/impls/binary/binv.c
Index of all Viewer routines
Table of Contents for all manual pages
Index of all manual pages

### Examples

src/vec/examples/tutorials/ex6.c.html
src/mat/examples/tutorials/ex5.c.html