clj-dbase.core — clj-dbase 0.1.0

A small library to parse dbase files. Copyright (C) 2020 Henrik Jürges [e-mail]

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

This module provides the utility to parse the dbase dbf table format into

The expected file format version is dBase v3. A dbf file starts with a variable header defining some metainformations and the field types and names. The remaining file is the record content.

Usage

The main entry point is the (parse-dbase-file input-file) function.

(def dbase-data (parse-dbase-file (clojure.java.io/file input-file)))

The returned data is a nested map of

{:header <meta informations>
 :fields <record field definitions>
 :records <the actual table data>}

Additionally, the field definition can be attatched to the record data.

(-> (java.io.file. input-file)
    (parse-dbase-file)
    (field-definition->records))

This results in the field name is also attached to the individual record for easier handling and post-processing.

abs clj

(abs n)

bytes->int clj

(bytes->int bytes)

Convert some bytes to an integer or uint32.

bytes->short clj

(bytes->short bytes)

Converts some bytes to a short or uint16.

calc-offset clj

(calc-offset fields offset fs)

Calculate the offset after which the first record starts.

enrich-record clj

(enrich-record fields record)

Add the field definitions as keywords to some record.

field-definition->records clj

(field-definition->records dbase-data)

Enrich the records with the field names as keywords.

next-byte? clj

(next-byte? stream pred)

Test the next byte from the input stream with pred.

The stream is resetted afterwards.

parse-dbase-fields clj

(parse-dbase-fields stream)

Parse all fields in the header.

The parsing stops at the first carriage return, ascii code 13.

parse-dbase-file clj

(parse-dbase-file file)

Take a dbase file and parse the file returnin a clojure map.

The consists of a :header part, the list of :fields definitions and the parsed :records data. At the moment only text and numbers are recognized as types.

parse-dbase-header clj

(parse-dbase-header file)

Take a dbase file of version 3 and parse the metadata and field information.

parse-dbase-metadata clj

(parse-dbase-metadata stream)

Parse the dbase header file from the input stream.

parse-dbase-records clj

(parse-dbase-records file fields header)

Parse the num of records defined in header and with the defined fields order.

parse-field clj

(parse-field stream)

Parse a record field definition from the input stream.

The skipped bytes are reserved for internal field adress in memory or other file format version then 3.

parse-field-name clj

(parse-field-name stream)

Parse the field name from the input stream.

parse-last-update-time clj

(parse-last-update-time stream)

Read the date from the input stream.

parse-record-field clj

(parse-record-field bytes field)

Converts the field into some appropriate clojure type.

The raw bytes of the record field. The header description of the field.

read-byte clj

(read-byte stream)

(read-byte stream n)

Read only one byte and optionaly skip n bytes

read-bytes clj

(read-bytes stream n)

(read-bytes stream n m)

The main byte reading function.

Read from stream n bytes and optional skip m bytes.

type-field clj

(type-field field-type bytes)

Convert the bytes to the field-type mentioned in the field header.