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The Programmer’s Guide to 1stReader for DOS (excerpt)

Release 2.00

Entire work Copyright 1995 by Mark Herring
All Rights Reserved

TABLE OF CONTENTS

Introduction

This manual was written for programmers who would like to add utilities and other programs into the 1stReader environment. Advanced 1stReader users may also find it useful in helping to understand how the 1stReader Applications Program Interface (API) works.

It is assumed that the reader is advanced in the ways of programming and using 1stReader.

1stReader was compiled using Microsoft’s QuickBasic 4.5 compiler system. So many of the conventions in this manual reflect a QuickBasic background. If you use a different computer language it is up to you to handle the conversions correctly.

The QWK format

Before we go into the details of the 1stReader API it might be of some benefit to review what makes up the QWK format. The QWK format was created in 1987 by Mark “Sparky” Herring for a friend who moved to a small town in Texas. The idea was to gather up all of the new messages posted on a bulletin board system and “quickly” transmit them to the user. Then the user could disconnect from the BBS and read the messages at their leisure using a QWK mail reader. If the user entered any new messages they could call the BBS back and upload their replies to the system.

Messaging volume took off as soon as QWK was introduced to the public. Suddenly, users could read a much larger number of messages “offline” than they could “online”. Users also found they could call bulletin board systems that were long distance and keep up with messages without spending a fortune. Sysops liked the QWK format because it allowed them to service more users per hour per node than without it.

Today, the QWK format is literally world-wide and is used by every major bulletin board software system. Millions of people download QWK mail packets daily to read answer their messages.

Through the years there have been extensions and additions made to the QWK format. We will only discuss the QWK format as it is supported by 1stReader.

Name and extension

The sysop of every bulletin board system that produces a QWK mail packet must have designated their own “QWK ID” for the BBS. The QWK ID is simply the name of the QWK mail packet without the QWK extension. If the mail packet is named “SPARKY.QWK” then the QWK ID for the BBS is simply “SPARKY”. The QWK is always eight characters or less, uses UPPER case letters and never includes a space, asterisk or question mark. It is used as the filename of the QWK mail packet so it must conform to standard DOS file naming conventions.

The extension of the QWK mail packet is always “.QWK”. However, if the user has more than one QWK mail packet on file for the same QWK ID then the second QWK mail packet uses the extension of “.QW0”. The third packet uses “.QW1”. The fourth packet uses “.QW2”, etc. Using this naming convention the QWK format supports up to 101 QWK mail packets on file for the same QWK ID.

Some QWK offline mail readers change the name of the QWK ID in the QWK mail packet to increment different packet names. This method is wrong because it changes the QWK ID of the system and makes it harder to locate all of the packets associated with the current QWK ID.

A QWK mail packet is almost always compressed using the ZIP format. Some bulletin board systems may use other file compression formats to produce their own QWK mail packets and this is acceptable. But, by and large, most systems today use the ZIP format to pack the files contained inside a QWK mail packet.

Files stored in a QWK mail packet

There are many different files that can be stored inside one QWK mail packet. The minimum files required by 1stReader are:

CONTROL.DAT

This file contains information about the BBS such as name, telephone number and conference names.

MESSAGES.DAT

This file stores the actual messages to be read by the user.

*.NDX

Index files. The “*” is replaced by the conference number. These files point to individual messages stored in the MESSAGES.DAT file.


Other files can be included in a standard QWK mail packet. These files include:

WELCOME

This file is the welcome display for the BBS. It is displayed immediately after 1stReader

BBSNEWS

Displays any news from the sysop to the user. 1stReader displays this file immediately after the WELCOME file.

GOODBYE

This file is displayed to the user when they decide to close the current QWK mail packet and return to the 1stReader menu.

ATTACHED.LST

If the QWK mail packet included any attached files then this file stores their filenames.


If the BBS is using a Qmail Door from Sparkware these files can also be included in the QWK mail packet:

OPTION.QM4

Stores a list of options available to the user when they use 1stReader’s “DOOR” button when reading messages.

SERVICE.QM4

Stores a list of services available to the user when they use 1stReader’s “DOOR” button when reading messages.

SERVICES.DAT

This file stores a list of services that were included by Qmail Door in the QWK mail packet.

Format for CONTROL.DAT

CONTROL.DAT is a text file with the following format:

Line#  Description
-----  -----------
  1    Name of the bulletin board system (40 characters)
  2    Blank
  3    Bulletin board's telephone number
  4    Name of the sysop
  5    Qmail Door serial number and QWK ID.  These two fields are
       separated by a comma.  The QWK ID is always stored in UPPER
       case letters.
  6    Date and time the QWK mail packet was created, separated by
       commas.
  7    User's login name
  8    Name of Qmail DeLuxe² menu file.  This file was displayed to
       users as a backdrop for the menu. 1stReader ignores this entry.
  9    Normally zero.  If this entry contains "-1" then the user is
       also the sysop.  This grants no special privs in our Qmail Door.
       The value is only present for the QWK reader's needs (if any).
 10    Usually zero, but if used it stores the total number of messages
       in the QWK mail packet.
 11    Number of conferences stored in CONTROL.DAT

The next lines in CONTROL.DAT store the conference number on the first line followed by the conference name on the next line. This is repeated for as many conferences as stored in CONTROL.DAT.

After the name of the last conference in the list in CONTROL.DAT the following lines are used:

Format of MESSAGES.DAT

MESSAGES.DAT is a binary file with a record length of 128 bytes.

The first record in MESSAGES.DAT contains the copyright notice “Produced by Qmail…Copyright (c) 1987 by Sparkware. All Rights Reserved”.

The first message in the file actually begins with LRN (logical record number) #2. It is here that you find the first message’s “header”. This header record tells 1stReader about the message that follows. The format for a message header is:

TYPE QWKType
    Status AS STRING * 1     'Status of message
    Number AS STRING * 7     'Message number
    Date AS STRING * 8       'Date
    Time AS STRING * 5       'Time
    MsgTo AS STRING * 25     'To
    MsgFrom AS STRING * 25   'From
    Subject AS STRING * 25   'Subject
    Password AS STRING * 12  'Password
    Reference AS STRING * 8  'Reference number
    Blocks AS STRING * 6     'Number of blocks
    Delete AS STRING * 1     'Current status of message
    Conference AS INTEGER    'Conference
    Blank AS STRING * 2      'Blank
    Tag AS STRING * 1        'Message tagline
END TYPE

“Status” is a string variable of one byte’s length. It can contain one of the following values:

“Number” is the message number as it exists on the bulletin board system. This field is seven bytes in length and is left justified.

“Date” and “Time” store the date and time the message was written to the bulletin board system.

“MsgTo” is a 25 byte field that stores the name of the user to whom the message was addressed.

“MsgFrom” is a 25 byte field that stores the name of the author of the message.

“Subject” is a 25 byte field that stores the subject of the message.

“Password” is a 12 byte field that contains the password of the message, if any. Note that 1stReader does not require a password in order to read the message since it is the mail door’s responsibility to insure that you only receive messages that YOU can read.

“Reference” is an eight byte field. If this message is a reply to a previous message then this field stores that previous message’s number on the BBS.

“Blocks” stores the number of 128 byte records used to store this message. Note that the message is counted as one of these blocks.

“Delete” is usually set to ASCII 225 to indicate that the message has not been deleted. If the message is deleted then this value stores ASCII 226.

“Conference” is a two byte INTEGER field that stores the conference number that contains this message. For example, if this message was found in conference #100 then this field will store “100” (in a signed INTEGER format).

“Blank” is set to NULLs.

“Tag” is set to “*” if the message was processed by our own QNet mail tosser.

The text of the message always follows the message header. ASCII 227 is used as the delimiter between lines of text. This code segment should help you understand how to read a message in MESSAGES.DAT:

DIM Qwk AS QWKType
Byte128$=STRING$(128,0)
OPEN "MESSAGES.DAT" FOR RANDOM AS #1 LEN=128
Record=2
GET #1,Record,Qwk
PRINT " Number:",Qwk.Number
PRINT "     To:",Qwk.MsgTo
PRINT "   From:",Qwk.MsgFrom
PRINT "Subject:",Qwk.Subject
PRINT
Buffer$=""
FOR i=1 TO VAL(Qwk.Blocks)-1
    GET #1,Record+i,Byte128$
    Buffer$=Buffer$+Byte128$
    DO
        In=INSTR(Buffer$,CHR$(227)
        IF In>0 THEN
            PRINT LEFT$(Buffer$,In-1)
            Buffer$=MID$(Buffer$,In+1)
        END IF
    LOOP WHILE In>0
NEXT
CLOSE #1

Format of the INDEX files

The .NDX files are used by 1stReader to locate individual messages in each conference. The name of each NDX file is used by 1stReader to determine the conference number. A filename of 050.NDX tells 1stReader that messages stored in the index belong to conference #50. As we discussed earlier, CONTROL.DAT stores the name of the conference so 1stReader puts the two together to identify both the conference name and its messages.

Any conference number less than 100 uses a leading ZERO to pad out the INDEX filespec.

INDEX files use a five byte logical record length so it is easy to find out how many messages are stored in one conference. Just divide the size of the INDEX file by FIVE and you will arrive at the number of messages stored in the conference.

The first four bytes of each INDEX record are a Microsoft Float Point Single Precision Format variable that contains the record number of the associated message header in MESSAGES.DAT. If you are using QuickBasic this value can be read by using the CVS() function. The fifth byte is unused by 1stReader.

If 1stReader wanted to read the third message in a conference it would first open the INDEX file for the conference and read the third record in the INDEX file. From there it would find the pointer in the first four bytes of the record and using the pointer would read the record number POINTER in MESSAGES.DAT to bring the message into the buffer.

Format for ATTACHED.LST

The file ATTACHED.LST lists the real name of attached files and uses the following format (one line per entry):

[conference #],[message #],[filename1],[filename2]

[conference #]      Conference where the request came from
[message #]         Message number where request came from
[filename1]         File as named inside the QWK mail packet
[filename2]         Original filename as stored on the BBS

The REP format

The REP format follows the QWK format very closely. It is used by 1stReader to store any replies or new messages the user enters with 1stReader. Later, this REP reply packet can be uploaded back to the BBS and its messages inserted into the correct conferences.

The REP reply packet also can store any files the user attached to messages. If attached files are included then the REP reply packet will include a ATTXREF.DAT file.

The REP reply packet is created using the same archiver method used to create the QWK mail packet.

Format for <QWK ID>.MSG

Each REP reply packet contains a .MSG file that uses the QWK ID of the current system as its filename. This was done to prevent a user from accidentally uploading a REP reply packet for one BBS to another BBS.

The .MSG file uses the same header record defined earlier for MESSAGES.DAT. There are only three differences between messages stored in MESSAGES.DAT and the .MSG file:

  1. The first record of the .MSG file contains the QWK ID for the current system in UPPER case letters. This was done to provide a second backup to prevent a user from accidentally uploading a REP reply packet for one BBS to another BBS.

  2. The destination conference for the reply (or new message) is stored in the “Number” field. If the reply was to be uploaded into conference #50 then the “Number” field stores “50” (left justified). The “Conference” field also stores the destination conference too.

  3. The .MSG file does not use an INDEX file. Rather, 1stReader scans the .MSG file each time the user joins the REPLIES conference and builds an index in memory. Since the file is dynamic, using an INDEX file would just complicate matters.

If a message is deleted in the .MSG file then the “Deleted” variable will contain an ASCII 226.

Format for ATTXREF.DAT

ATTXREF.DAT file is a text file that stores the names of any attached files included in the REP reply packet. If there are, for example, ten replies on file then ATTXREF.DAT will contain ten lines of mostly empty text. If the third message in the .MSG file included an attached message then the third line of ATTXREF.DAT would store information about the attached file using this format:

Internal filename,Real filename

“Internal filename” is the name of the attached file as it is stored in the REP reply packet. “Real filename” is the name of the file as it should be renamed once the REP reply packet is uploaded back to the BBS.

Note that the QWK mail system on the destination BBS handles the renaming of the files.