Getting Started

Chapter Updated 8/14/03

Overview

Welcome to Xbase DBMS. Xbase DBMS is a collection of specifications, programs, utilities and a C++ class library for manipulating Xbase type datafiles and indices. Xbase has been developed and produced by several people from around the world via the internet.

The term Xbase is often used used to describe the format of the original DBase, Clipper and Foxbase (.DBF) files. Many vendors support the industry standard Xbase file format and are committed to this technology for many years to come, thus insuring continued support.

The original purpose of the Xbase library was to provide reliable and economical programming tools to programmers for reading, writing and updating DBF databases, indices and memo fields.

System Requirements

To use Xbase DBMS, the following items are needed:

A computer and C/C++ compiler.

The original source code is developed on a Linux platform with the GCC public domain C/C++ compiler.

Xbase DBMS has been successfully ported and runs on Linux, Sun Solaris, OpenVMS, FreeBSD, OS2 and DOS/Windows (Using the large memory model).

This software is not intended to be used on any system using an SCO operating system.

Classes and User Interface

There are six classes in the Xbase library which are available for use in a typical Xbase application program.

Xbase Classes - Version 1.8.0 and newer
Class	Basic Description	How Used	Old Class Name
xbXBase	Basic Xbase Class	Every program gets one of these	XBASE
xbDbf	Database and Field class	Need one of these for each open DBF file	DBF
xbNdx	Ndx index class	Need one of these for each open NDX index	NDX
xbNtx	Ntx index class	Need one of these for each open NTX index
xbString	String class	Used for handling strings
xbHtml	Html generation class	Needed for creating HTML code	HTML

There are other classes used internally by these Xbase classes, but most application programs need not to be concerned with. These classes are xbStack - used for stack data structures, xbExpn - used for expression logic, and xbDate - used for date manipulation logic.

Portability, Type Defs and Structures

To effectively make the Xbase library as portable across platforms as possible, three things occured.

First, the software was developed to run and compile on either big endian or little endian computers and store all numeric data in little endian format.

Secondly, field types must be consistently defined in each environment. The types.h file defines the xbase data types. To modify the Xbase code base to function in a different (non ported to yet) environment, start by modifying the types.h file for your site and recompile.

Thirdly, support for unix automake and autoconf has been to provided support on a wide variety of unices.

Field Types
Type	Description
xbULong	unsigned long int
xbUShort	unsigned short int
xbShort	short int
xbLong	long
xbFloat	float
xbDouble	double
char	char
void	void
struct SCHEMA	Used for defining record structures

Xbase was designed for portability utilizing standard ANSI-C compliant code. If you decide to write updates to the Xbase project, please try to keep your work to standard generic ANSI-C (no special DOS/WINDOWS Calls).

Compilation Overview

If you are building the sources on a Linux/Unix platform:

Download the source
./configure
make
su
make install
exit

Before compiling the library, you may need to modify the options for your environment. Do "./configure --help" for a list of the current options

On my server, I had to:

Verify the library and associated links were copied from xbase/xbase/.libs into /usr/local/lib

Add /usr/local/lib is in /etc/ld.so.conf

execute program ldconfig as root to refresh the new libs

Actual milage at your site may vary.

Building a program with the Xbase library

Create a directory for your project:

cd /home/me
mkdir MyProject
cd MyProject
vi MyProg.cpp

To use the Xbase classes, include the following header file in the program:

#include <xbase/xbase.h>

For more details, check out the sample programs in the xbase/examples directory.

Compiling and Linking Unix Application Program for v3.0 later

The install script should have provided specific instructions for your environment on how to link with the xbase library.

In the Linux environment, assuming that you are using shared libraries, and usr/local/lib has been added to the /etc/ld.so.conf file, and the ldconfig command was executed

To Compile:
g++ -c -Wall -I/usr/include -I/usr/src/linux/include-asm-i386 -I/usr/local/include -I/usr/local/xbase myprog.cpp

To Link Edit:
g++ -o myprog myprog.o libxbase.so

Compiling an Application Program with Borland v4.5 C/C++compiler

With Borland C compiler: bcc -Ic:\xbase\src myprog.cpp -Lc:\xbase\src\xbase.lib

Getting the latest development version of XBase

The Xbase project is in an ongoing state of development with new enhancements being added and bug fixes being applied as they are found and the package maintainers have time. There are several programmers from various parts of the world working on Xbase. If you would like to get the latest version of the Xbase library for your project, it is available on sourceforge.net.

Notes about using the current development library

1 - Library functions may or may not be documented

2 - The library may or may not be stable. This is the development library and is being updated with current code changes. If you are using it, and it does not behave the way you think it should, you may want to drop a note to xdb-devel@lists.sourceforge.net This may sound a little unsettling, but the library is generally stable. It goes through periods of time where it is in a state of flux when major changes are occurring, but for the most part it is probably OK to use.

3 - If you have changes to contribute to the library, mail your updates to xdb-devel@lists.sourceforge.net
.

System Limitations

Maximum size of a database file is the size of LONG - 2,147,483,647 bytes
Total number of fields in a database - 1024
Total number of characters in all fields - 32767
Maximum number of characters in a field - 254
Total number of records in a file - 1 billion
Maximum index key length - 100 bytes
Maximum .DBT file memo block size - 32256
Maximum expression result length - 100 bytes
Maximum NDX index key length - 100 bytes

Xbase Options - Unix Automake environment
OPTION	DESCRIPTION
--without-xbase-debug	Turns off xbase debugging code
--without-index-ndx	Turns off NDX index options
--without-index-ntx	Turns off NTX index options
--without-memo-fields	Turns off memo fields
--without-expressions	Turns off expression processing
--without-ui-html	Turns off HTML user interface class
--without-xbase-locking	Turns off xbase locking
--without-xbase-debug	Turns off debug logic
--without-exceptions	Turns on exception processing
--with-castellano	Turn on castellano/spanish date options
--without-realdelete	Turn off Xbase record deletion
--without-xbase-filter	Turn off Xbase filter logic

Use these options on the command line when executing the ./configure command. Also, you can execute ./configure --help for a complete list of all unix configure options.

Q Why turn any of thes options off?
A Smaller library