Update a submodule. This will clone a missing submodule and checkout the subrepository to the commit specified in the index of containing repository.
If the submodule is not initialized, setting this flag to true will initialize the submodule before updating. Otherwise, this will return an error if attempting to update an uninitialzed repository. but setting this to true forces them to be updated.
configuration options for the update. If NULL, the function works as though GIT_SUBMODULE_UPDATE_OPTIONS_INIT was passed.
0 on success, any non-zero return value from a callback function, or a negative value to indicate an error (use giterr_last
for a detailed error message).