| DBM_CLEARERR(3) | Library Functions Manual | DBM_CLEARERR(3) | 
dbm_clearerr, dbm_close,
  dbm_delete, dbm_dirfno,
  dbm_error, dbm_fetch,
  dbm_firstkey, dbm_nextkey,
  dbm_open, dbm_store,
  ndbm —
#include <ndbm.h>
int
  
  dbm_clearerr(DBM
    *db);
void
  
  dbm_close(DBM
    *db);
int
  
  dbm_delete(DBM
    *db, datum
  key);
int
  
  dbm_dirfno(DBM
    *db);
int
  
  dbm_error(DBM
    *db);
datum
  
  dbm_fetch(DBM
    *db, datum
  key);
datum
  
  dbm_firstkey(DBM
    *db);
datum
  
  dbm_nextkey(DBM
    *db);
DBM *
  
  dbm_open(const
    char *file, int
    open_flags, mode_t
    file_mode);
int
  
  dbm_store(DBM
    *db, datum key,
    datum content,
    int store_mode);
ndbm facility provides access to hash database
  files.
Two data types are fundamental to the ndbm
    facility. DBM serves as a handle to a database. It is
    an opaque type.
The other data type is datum, which is a structure type which includes the following members:
void * dptr size_t dsize
A datum is thus given by dptr pointing at an object of dsize bytes in length.
The dbm_open() function opens a database.
    The file argument is the pathname which the actual
    database file pathname is based on. This implementation uses a single file
    with the suffix .db appended to
    file. The open_flags argument
    has the same meaning as the flags argument to
    open(2) except that when opening
    a database for write-only access the file is opened for read/write access,
    and the O_APPEND flag must not be specified. The
    file_mode argument has the same meaning as the
    mode argument to
    open(2).
For the following functions, the db argument
    is a handle previously returned by a call to
    dbm_open().
The dbm_close() function closes a
    database.
The dbm_fetch() function retrieves a
    record from the database. The key argument is a
    datum that identifies the record to be fetched.
The dbm_store() function stores a record
    into the database. The key argument is a
    datum that identifies the record to be stored. The
    content argument is a datum that
    specifies the value of the record to be stored. The
    store_mode argument specifies the behavior of
    dbm_store() if a record matching
    key is already present in the database,
    db. store_mode must be one of
    the following:
DBM_INSERTDBM_REPLACEIf no record matching key is present, a new record is inserted regardless of store_mode.
The dbm_delete() function deletes a record
    from the database. The key argument is a
    datum that identifies the record to be deleted.
The dbm_firstkey() function returns the
    first key in the database.
The dbm_nextkey() function returns the
    next key in the database. In order to be meaningful, it must be preceded by
    a call to dbm_firstkey().
The dbm_error() function returns the error
    indicator of the database.
The dbm_clearerr() function clears the
    error indicator of the database.
The dbm_dirfno() function returns the file
    descriptor of the underlying database file.
ndbm facility is implemented on top of the
  hash(3) access method of the
  db(3) database facility.
dbm_open() function returns a pointer to a
  DBM when successful; otherwise a null pointer is
  returned.
The dbm_close() function returns no
  value.
The dbm_fetch() function returns a content
    datum; if no record matching key
    was found or if an error occured, its dptr member is a
    null pointer.
The dbm_store() function returns 0 when
    the record was successfully inserted; it returns 1 when called with
    store_mode being DBM_INSERT
    and a record matching key is already present;
    otherwise a negative value is returned.
The dbm_delete() function returns 0 when
    the record was successfully deleted; otherwise a negative value is
  returned.
The dbm_firstkey() and
    dbm_nextkey() functions return a key
    datum. When the end of the database is reached or if
    an error occured, its dptr member is a null
  pointer.
The dbm_error() function returns 0 if the
    error indicator is clear; if the error indicator is set a non-zero value is
    returned.
The dbm_clearerr() function always returns
    0.
The dbm_dirfno() function returns the file
    descriptor of the underlying database file.
dbm_clearerr(), dbm_close(),
  dbm_delete(), dbm_error(),
  dbm_fetch(), dbm_firstkey(),
  dbm_nextkey(), dbm_open(), and
  dbm_store() functions conform to
  X/Open Portability Guide Issue 4, Version 2
  (“XPG4.2”) and Version 2 of the
  Single UNIX Specification (“SUSv2”). The
  dbm_dirfno() function is an extension.
| May 5, 2010 | NetBSD 9.4 |