# PetscOptionsAllUsed
Returns a count of the number of options in the database that have never been selected. 
## Synopsis
```
#include "petscsys.h"   
PetscErrorCode PetscOptionsAllUsed(PetscOptions options, PetscInt *N)
```
Not Collective


## Input Parameter

- ***options -*** options database, use NULL for default global database



## Output Parameter

- ***N -*** count of options not used





## Note
The value returned may be different on each process and depends on which options have been processed
on the given process


## See Also
 `PetscOptionsView()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/objects/options.c.html#PetscOptionsAllUsed">src/sys/objects/options.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/tutorials/ex3f.F90.html">src/sys/tutorials/ex3f.F90.html</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/objects/options.c)


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