DBM(3) BSD Library Functions Manual DBM(3)

NAME
     ddbbmmcclleeaarreerrrr, ddbbmmcclloossee, ddbbmmddeelleettee, ddbbmmddiirrffnnoo, ddbbmmeerrrroorr, ddbbmmffeettcchh,
     ddbbmmffiirrssttkkeeyy, ddbbmmnneexxttkkeeyy, ddbbmmooppeenn, ddbbmmssttoorree - database access func-
     tions

SYNOPSIS
     ##iinncclluuddee <>
     ##iinncclluuddee <>

     DBM *
     ddbbmmooppeenn(const char *base, int flags, int mode);

     void
     ddbbmmcclloossee(DBM *db);

     int
     ddbbmmssttoorree(DBM *db, datum key, datum data, int flags);

     datum
     ddbbmmffeettcchh(DBM *db, datum key);

     int
     ddbbmmddeelleettee(DBM *db, datum key);

     datum
     ddbbmmffiirrssttkkeeyy(DBM *db);

     datum
     ddbbmmnneexxttkkeeyy(DBM *db);

     int
     ddbbmmeerrrroorr(DBM *db);

     int
     ddbbmmcclleeaarreerrrr(DBM *db);

     int
     ddbbmmddiirrffnnoo(DBM *db);

DESCRIPTION
     Database access functions.  These functions are implemented using
     dbopen(3) with a hash(3) database.

     datum is declared in :

     typedef struct {
             char *dptr;
             int dsize;
     } datum;

     The ddbbmmooppeenn(base, flags, mode) function opens or creates a database.
     The base argument is the basename of the file containing the database;
     the actual database has a .db suffix.  I.e., if base is
     "/home/me/mystuff" then the actual database is in the file
     /home/me/mystuff.db.  The flags and mode arguments are passed to open(2).
     (ORDWR | OCREAT) is a typical value for flags; 0660 is a typical value
     for mode.  OWRONLY is not allowed in flags.  The pointer returned by
     ddbbmmooppeenn() identifies the database and is the db argument to the other
     functions.  The ddbbmmooppeenn() function returns NULL and sets errno if there
     were any errors.

     The ddbbmmcclloossee(db) function closes the database.  The ddbbmmcclloossee() function
     normally returns zero.

     The ddbbmmssttoorree(db, key, data, flags) function inserts or replaces an entry
     in the database.  The flags argument is either DBMINSERT or DBMREPLACE.
     If flags is DBMINSERT and the database already contains an entry for
     key, that entry is not replaced.  Otherwise the entry is replaced or
     inserted.  The ddbbmmssttoorree() function normally returns zero but returns 1
     if the entry could not be inserted (because flags is DBMINSERT, and an
     entry with key already exists) or returns -1 and sets errno if there were
     any errors.

     The ddbbmmffeettcchh(db, key) function returns NULL or the data corresponding to
     key.

     The ddbbmmddeelleettee(db, key) function deletes the entry for key.  The
     ddbbmmddeelleettee() function normally returns zero but returns 1 if there was no
     entry with key in the database or returns -1 and sets errno if there were
     any errors.

     The ddbbmmffiirrssttkkeeyy(db) function returns the first key in the database.  The
     ddbbmmnneexxttkkeeyy(db) function returns subsequent keys.  The ddbbffiirrssttkkeeyy()
     function must be called before ddbbmmnneexxttkkeeyy().  The order in which keys
     are returned is unspecified and may appear random.  The ddbbmmnneexxttkkeeyy()
     function returns NULL after all keys have been returned.

     The ddbbmmeerrrroorr(db) function returns the errno value of the most recent
     error.  The ddbbmmcclleeaarreerrrr(db) function resets this value to 0 and returns
     0.

     The ddbbmmddiirrffnnoo(db) function returns the file descriptor to the database.

SEE ALSO
     open(2), dbopen(3), hash(3)

STANDARDS     These functions (except ddbbmmddiirrffnnoo()) are included in the Version 2 of
     the Single UNIX Specification (``SUSv2'').

BSD                              July 7, 1999                              BSD