# PetscViewerCheckWritable
Check whether the viewer can be written to, generates an error if not 
## Synopsis
```
#include "petscviewer.h" 
PetscErrorCode PetscViewerCheckWritable(PetscViewer viewer)
```
Collective


## Input Parameters

- ***viewer -*** the `PetscViewer` context





## See Also
 [](sec_viewers), `PetscViewer`, `PetscViewerWritable()`, `PetscViewerCheckReadable()`, `PetscViewerCreate()`, `PetscViewerFileSetMode()`, `PetscViewerFileSetType()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/viewer/interface/view.c.html#PetscViewerCheckWritable">src/sys/classes/viewer/interface/view.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/classes/viewer/interface/view.c)


[Index of all Viewer routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
