:orphan:
# PetscOptionsBool
Determines if a particular option is in the database with a true or false 
## Synopsis
```
#include "petscsys.h"
PetscErrorCode PetscOptionsBool(const char opt[],const char text[],const char man[],PetscBool currentvalue,PetscBool  *flg,PetscBool  *set)
```
Logically Collective on the communicator passed in `PetscOptionsBegin()`


## Input Parameters

- ***opt -*** option name
- ***text -*** short string that describes the option
- ***man -*** manual page with additional information on option
- ***currentvalue -*** the current value



## Output Parameters

- ***flg -*** ` PETSC_TRUE` or `PETSC_FALSE`
- ***set -*** `PETSC_TRUE` if found, else `PETSC_FALSE`





## Notes
TRUE, true, YES, yes, nostring, and 1 all translate to `PETSC_TRUE`
FALSE, false, NO, no, and 0 all translate to `PETSC_FALSE`

If the option is given, but no value is provided, then flg and set are both given the value `PETSC_TRUE`. That is `-requested_bool`
is equivalent to `-requested_bool true`

If the user does not supply the option at all `flg` is NOT changed. Thus
you should ALWAYS initialize the `flg` variable if you access it without first checking if the `set` flag is `PETSC_TRUE`.

Must be between a `PetscOptionsBegin()` and a `PetscOptionsEnd()`


## See Also
 `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`, `PetscOptionsGetInt()`,
`PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsGetBool()`,
`PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
`PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
`PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
`PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
`PetscOptionsFList()`, `PetscOptionsEList()`

## Level
beginner

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c.html">src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/field/tutorials/ex1.c.html">src/dm/field/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/forest/tutorials/ex1.c.html">src/dm/impls/forest/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex10.c.html">src/dm/impls/plex/tutorials/ex10.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex11.c.html">src/dm/impls/plex/tutorials/ex11.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex13.c.html">src/dm/impls/plex/tutorials/ex13.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex5.c.html">src/dm/impls/plex/tutorials/ex5.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex8.c.html">src/dm/impls/plex/tutorials/ex8.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/tutorials/ex9.c.html">src/dm/impls/plex/tutorials/ex9.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/label/tutorials/ex1.c.html">src/dm/label/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex10.c.html">src/ksp/ksp/tutorials/ex10.c</A><BR>


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


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