PetscOptionsString#

Gets the string value for a particular option in the database.

Synopsis#

#include <petscoptions.h>
PetscErrorCode PetscOptionsString(const char opt[], const char text[], const char man[], const char currentvalue[], char value[], size_t len, 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; caller is responsible for setting this value correctly. This is not used to set value
len - length of the result string including null terminator

Output Parameters#

value - the value to return
set - PETSC_TRUE if found, else PETSC_FALSE

Notes#

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

If the user provided no string (for example -optionname -someotheroption) set is set to PETSC_TRUE (and the string is filled with nulls).

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

The currentvalue passed into this routine does not get transferred to the output value variable automatically.