Learn the number of types defined in a group, and their IDs.
int nc_inq_typeids(int ncid, int *ntypes, int *typeids);
ncid
ntypes
typeids
NC_NOERR
NC_BADID
The following example is from the test program libsrc4/tst_enums.c.
if (nc_open(FILE_NAME, NC_NOWRITE, &ncid)) ERR; /* Get type info. */ if (nc_inq_typeids(ncid, &ntypes, typeids)) ERR; if (ntypes != 1 || !typeids[0]) ERR;