dbopen - open default database
dbopen (dbname) char *dbname;
Dbopen opens a database for further use. The database name becomes the default when parsing or opening logical names. The named database must exist in the C/Base database catalog. If a log file is associated with the database, it is opened at this time. Upon successful opening of the database, a value of 0 (zero) is returned. The default database name plays an important role in parsing logical names. If the database name is not explicitly given, the default is used. The default database name can be changed by issuing multiple dbopen calls provided that the log file names are the same for each database. If dbname is an empty string or a NULL pointer, the environment variable DBASE names the database.
Dbopen returns a non-zero value if the database cannot be opened
and sets the RMS error message describing the reason.