Returns the next key in a database.
DBM Library (libdbm.a)
#include <dbm.h>
  datum nextkey ( key)
datum key;
The nextkey subroutine returns the next key in a database.
| Item | Description | 
|---|---|
| key | Specifies the input key. This value has no effect on the return value, but must be present. | 
Returns a datum structure containing the next key-value pair.