# PetscOptionsTruthGroupBegin

First in a series of logical queries on the options database for which only a single value can be true.

### Synopsis

    #include "petsc.h"
    PetscErrorCode  PetscOptionsTruthGroupBegin(const char opt[],const char text[],const char man[],PetscTruth *flg)

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

### Output Parameter

flg -whether that option was set or not

Notes: Must be between a PetscOptionsBegin() and a PetscOptionsEnd()

Must be followed by 0 or more PetscOptionsTruthGroup()s and PetscOptionsTruthGroupEnd()

### See Also

PetscOptionsGetInt(), PetscOptionsGetReal(),
PetscOptionsHasName(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsTruth(), PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(), PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(), PetscOptionsTruthGroupBegin(), PetscOptionsTruthGroup(), PetscOptionsTruthGroupEnd(), PetscOptionsList(), PetscOptionsEList()

Level:intermediate
Location:src/sys/objects/aoptions.c
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages