:orphan:
# PetscViewerFileSetMode
Sets the open mode of file
## Synopsis
```
#include "petscviewer.h"
PetscErrorCode PetscViewerFileSetMode(PetscViewer viewer, PetscFileMode mode)
```
Logically Collective
## Input Parameters
- ***viewer -*** the `PetscViewer`; must be a a `PETSCVIEWERBINARY`, `PETSCVIEWERMATLAB`, `PETSCVIEWERHDF5`, or `PETSCVIEWERASCII` `PetscViewer`
- ***mode -*** open mode of file
```none
FILE_MODE_WRITE - create new file for output
FILE_MODE_READ - open existing file for input
FILE_MODE_APPEND - open existing file for output
```
## See Also
[](sec_viewers), `PetscViewerFileSetMode()`, `PetscViewerCreate()`, `PetscViewerSetType()`, `PetscViewerBinaryOpen()`
## Level
advanced
## Location
src/sys/classes/viewer/impls/binary/binv.c
## Examples
src/dm/tutorials/ex15.c
src/dm/tutorials/ex20.c
src/dm/tutorials/ex21.c
src/ksp/ksp/tutorials/ex43.c
src/ksp/ksp/tutorials/ex70.c
src/mat/tutorials/ex10.c
src/snes/tutorials/ex12.c
src/sys/classes/viewer/tutorials/ex1.c
src/ts/tutorials/ex11.c
src/ts/tutorials/ex11_sa.c
## Implementations
PetscViewerFileSetMode_ExodusII in src/dm/impls/plex/plexexodusii.c
PetscViewerFileSetMode_ADIOS in src/sys/classes/viewer/impls/adios/adios.c
PetscViewerFileSetMode_ASCII in src/sys/classes/viewer/impls/ascii/filev.c
PetscViewerFileSetMode_Binary in src/sys/classes/viewer/impls/binary/binv.c
PetscViewerFileSetMode_CGNS in src/sys/classes/viewer/impls/cgns/cgnsv.c
PetscViewerFileSetMode_HDF5 in src/sys/classes/viewer/impls/hdf5/hdf5v.c
PetscViewerFileSetMode_Matlab in src/sys/classes/viewer/impls/matlab/vmatlab.c
PetscViewerFileSetMode_VTK in src/sys/classes/viewer/impls/vtk/vtkv.c
PetscViewerFileSetMode_VU in src/sys/classes/viewer/impls/vu/petscvu.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/classes/viewer/impls/binary/binv.c)
[Index of all Viewer routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)