0. Changes
        a. I realized that a driver manager doesn't aware of
           difference between a C5 (i.e. hstmt) and a C6
           (i.e. transaction) states.

        b. The link flags "-lc" has been removed from Linux ELF
           section of Config.mk to fix a segment fault problem.
           Now, it works fine on Slackware 2.3 and Red Hat 2.0
           (kernel version are 1.2.xx and 1.3.xx respectively).

        c. On FreeBSD 2.x, dlsym() doesn't handle the '_'
           prepended before a exporting function symbol. So,
           CLI_NAME_PREFIX needs to be defined as "_SQL" for
           FreeBSD.

        d. Some files are renamed
                dld.c   -> dlf.c
                dld.h   -> dlf.h
                confg.h -> config.h

1. iODBC driver manager platform availability

   iODBC driver manager has been ported to following Unix platforms:

        SunOS           4.1.x           Sun Sparc
        HP/UX           9.x, 10.x       HP9000 s700/s800
        HP/UX           9.x             HP9000 s300/s400
        IBM AIX         3.x, 4.x        IBM RS6000, PowerPC
        Sun Solaris     2.x             Sun Sparc, PCx86
        SGI Irix SVR4   5.x, 6.x        IP12 MIPS, IP22 MIPS
        NCR SVR4        3.x             NCR 3435
        UnixWare SVR4.2 1.x, 2.x        x86
        DEC Unix(OSF/1) 3.x, 4.x        DEC Alpha
        FreeBSD         2.x             x86
        BSDI BSD/OS     2.x             ?
        Linux ELF       1.2.x, 1.3.x    x86
        SCO OpenServer  5.x             x86
        Max/OS SVR4     1.x             Concurrent Maxion 9200 MP
        DG/UX           5.x             Aviion

   Porting of iODBC driver manager to some non-unix operating systems
   such as Windows family(3.x, 95, NT), OS/2 and Mac is supported but
   has never compiled and tested yet :). Of cause, you need to supply
   a make/build file and a short LibMain for creating the iodbc.dll.

2. How to build iODBC driver manager:

        step 1. Identify your system
        step 2. Run build with a suitable option

   Here is an example:

        %[1]: sh iodbc-2.12.shar
        ....
        %[2]: cd iodbc-2.12
        %[3]: uname -s -v -r -m
        HP-UX B.10.01 A 9000/710
        %[4]: ./build hp700
        autoconfig hp700
        make
        ....
        Generating iODBC driver manager --> /home/kejin/iodbc-2.12.sl

3. odbc.ini( ~/.odbc.ini )

   Driver manager and drivers use odbc.ini(or ~/.odbc.ini on Unix) file
   or connection string when establishing a data source connection. On
   Windows, odbc.ini is located in Windows directory. On unix, iODBC driver
   manager(and all other ODBC drivers and driver managers I awared) looks
   .odbc.ini file in real user's home directory (it could be a softlink to
   the file located somewhere else). Make sure your driver will look into
   the same file (or a file which is a symbolic link to the same file).
   The format of odbc.ini( or ~/.odbc.ini ) is defined as:

        odbc.ini(or .odbc.ini) ::= data_source_list

        data_source_list ::= /* empty */
                           | data_source '\n' data_source_list

        data_source ::= '[' data_source_name ']' '\n' data_source_desc

        data_source_name ::= 'default' | [A-Za-z]*[A-Za-z0-9_]*

        data_source_desc ::= /* empty */
                           | attrib_desc '\n' data_source_desc

        addrib_desc ::= Attrib '=' attrib_value

        Attrib ::= 'Driver' | 'PID' | 'UID' | driver_def_attrib

        driver_def_attrib ::= [A-Za-z]*[A-Za-z0-9_]*

   An example of .odbc.ini file:

        [toronto_yp]
        # yellow page of metro Toronto
        Driver = /usr/lib/odbc/oracle.so
        <....>

        [toronto_wp]
        # white page of metro Toronto
        Driver = /usr/lib/odbc/oracle.so
        <....>

        [contract]
        # all contract documents
        Driver = /usr/lib/odbc/informix.so
        <....>

        [netnews]
        # NNTP netnews group
        Driver = /usr/lib/odbc/nnodbc.so
        Server = news.empress.com

        [rnd_test]
        # data source for R&D test
        Driver = /home/r_d/odbc/empodbc.so
        URL = empodbc://rnd.empress.com:6322/rnd_test/testdb

        [default]
        # default to odbc gateway
        Driver = /usr/lib/odbc/gateway.so

4. Tracing

   iODBC driver manager traces driver's ODBC call invoked by the driver
   manager. Default tracing file is ./odbc.log. Tracing option (i.e.
   on/off or optional tracing file name) can be set in ~/.odbc.ini
   file (under a data source section) as:

        TraceFile = <optional_trace_file>
        Trace = ON | On | on | 1 | OFF | Off | off | 0

   If <optional_trace_file> is stderr or stdout, i.e.

        TraceFile = stderr

   or

        TraceFile = stdout

   the tracing message will go to the terminal screen(if it is available).

   iODBC driver manager allows one to tune on/off tracing on selected
   connection(s). Different connections can share one or use different
   tracing file(s). ODBC calls on connections without tuning tracing on
   will not be traced.

5. File list:

        README          This file
        IAFA-PACKAGE    Version and copyright information
        Changes.log     Source changes log
        Version.mk      Version make include file
        Config.mk       Config  make include file
        Makefile        make file
        config.h        system config include file
        isql.h          ODBC 1.0 macro
        isqlext.h       ODBC 2.0 macro
        dlf.h           general dynamic loader module interface
        dlf.c           general dynamic loader module (mapping to svr4)
        dlproc.h        simple dynamic loader module interface
        dlproc.c        simple dynamic loader on top of dlf module
        herr.h          error handling module interface
        herr.c          error handling module
        herr.ci         error handling source include
        henv.h          environment handle interface
        henv.c          environment handle module
        henv.ci         environment handle source include
        hdbc.h          connection handle interface
        hdbc.c          connection handle module
        hstmt.h         statement  handle interface
        hstmt.c         statement  handle module
        connect.c       connect functions
        prepare.c       query prepare functions
        execute.c       query executing functions
        result.c        query result property functions
        fetch.c         query result fetch functions
        info.c          driver information functions
        catalog.c       catalog functions
        misc.c          miscellaneous functions
        itrace.h        macro
        itrace.c        trace function
        main.c          entry function used to build a share library on AIX
        shrsub.exp      export symbol list used on AIX
        autoconfig      shell script for creating Config.mk
        build           shell script for building iodbc driver manager
