sasl_getrealm_t man page
sasl_getrealm_t — Realm Acquisition Callback
#include <sasl/sasl.h> int sasl_getrealm_t(void *context, int id, const char **availrealms, const char **result)
sasl_getrealm_t is used when there is an interaction with SASL_CB_GETREALM as the type.
If a mechanism would use this callback, but it is not present, then the first realm listed is automatically selected. (Note that a mechanism may still force the existence of a getrealm callback by SASL_CB_GETREALM to its required_prompts list).
context context from the callback record
id callback ID (SASL_CB_GETREALM)
availrealms A string list of the available realms. NULL terminated, may be empty.
result The chosen realm. (a NUL terminated string)
SASL callback functions should return SASL return codes. See sasl.h for a complete list. SASL_OK indicates success.