Module Dbm

module Dbm: sig .. end

Interface to the NDBM database.

type t

The type of file descriptors opened on NDBM databases.

type open_flag =

`\|`	`Dbm_rdonly`
`\|`	`Dbm_wronly`
`\|`	`Dbm_rdwr`
`\|`	`Dbm_create`	`(*`	Flags for opening a database (see `Dbm.opendbm`).	`*)`

exception Dbm_error of string

Raised by the following functions when an error is encountered.

val opendbm : string -> open_flag list -> int -> t

Open a descriptor on an NDBM database. The first argument is the name of the database (without the .dir and .pag suffixes). The second argument is a list of flags: Dbm_rdonly opens the database for reading only, Dbm_wronly for writing only, Dbm_rdwr for reading and writing; Dbm_create causes the database to be created if it does not already exist. The third argument is the permissions to give to the database files, if the database is created.

val close : t -> unit

Close the given descriptor.

val find : t -> string -> string

find db key returns the data associated with the given key in the database opened for the descriptor db. Raise Not_found if the key has no associated data.

val add : t -> string -> string -> unit

add db key data inserts the pair (key, data) in the database db. If the database already contains data associated with key, raise Dbm_error "Entry already exists".

val replace : t -> string -> string -> unit

replace db key data inserts the pair (key, data) in the database db. If the database already contains data associated with key, that data is discarded and silently replaced by the new data.

val remove : t -> string -> unit

remove db key data removes the data associated with key in db. If key has no associated data, raise Dbm_error "dbm_delete".

val firstkey : t -> string

See Dbm.nextkey.

val nextkey : t -> string

Enumerate all keys in the given database, in an unspecified order. firstkey db returns the first key, and repeated calls to nextkey db return the remaining keys. Not_found is raised when all keys have been enumerated.

val iter : (string -> string -> 'a) -> t -> unit

iter f db applies f to each (key, data) pair in the database db. f receives key as first argument and data as second argument.