MAINKERMIT User's Guide, Chapter 1

previous   next   top   contents   index   framed top   this page unframed


1. Overview of MAINKERMIT

MAINKERMIT is a version of the Kermit file transfer utility implemented in the portable programming language MAINSAIL. The Kermit protocol was developed by the Columbia University Center for Computing Activities. Kermit is available for a variety of system for a nominal fee from Columbia and from various user group organizations, such as DECUS and SHARE. MAINKERMIT is available in source form on XIDAK's MAINSAIL Public Tape, which can be obtained from XIDAK, at XIDAK's standard media production fee. MAINKERMIT is also shipped in object form to all MAINSAIL users licensed to use the MAINSAIL STREAMS package.

This manual is intended to be used as a supplement to an authoritative reference on Kermit, such as the KERMIT User Guide (fifth edition. New York: Columbia University Center for Computing Activities, 1984) or KERMIT: A File Transfer Protocol (Bedford, Massachusetts: Digital Press, 1987), both by Frank da Cruz. It is assumed that the reader is familiar with basic Kermit concepts, such as “local” and “remote” Kermits, and is familiar with the use of a “typical” Kermit. Copies of Kermit documentation and sources for other Kermit implementations can be obtained from them by writing to:

Kermit Distribution
Columbia University Center for Computing Activities
612 West 115th Street
New York, NY  10025

MAINKERMIT at a Glance
Local operation *
Remote operation Yes
Login scripts No
Transfer text files Yes
Transfer data files Yes
Wildcard send No
File transfer interruption Yes
File name collision avoidance No
Can time out *
8th-bit prefixing Yes
Repeat count prefixing Yes
Alternate block checks Yes
Terminal emulation *
Communication settings *
Transmit BREAK *
Support for dialout modems Yes
IBM mainframe communication Yes
Transaction logging Yes
Session logging No
Debug logging No
Packet logging Yes
Act as server Yes
Talk to server Yes
Advanced server functions Yes
Local file management Yes
Command/Init files Yes
File Attribute packets Yes
Command macros No
Raw file transmit No
* Depends on capabilities provided by the operating system.

MAINKERMIT has been designed to run interactively. Although no wildcard send is currently allowed, a list of files can be specified to be sent as a batch. Also, because File Attribute packets have been implemented, text and data files can be intermixed when two MAINKERMITs are talking to each other.

1.1. Version

This version of the MAINKERMIT User's Guide is current as of the proposed Version 16.30.1 of MAINSAIL (which has not yet been released).

This document is preliminary. Its contents have been updated to include information about the proposed 16.30.1 release, but the document has not been thoroughly proofread. Please contact XIDAK if you have any questions concerning this document or if you find any errors in it.

1.2. File Names and Types

MAINKERMIT was designed to be a highly portable, full-featured Kermit, which can reliably transfer both text and data files. Due to the implementation of File Attribute packets, a mixture of text and data files can be batched and sent with no user intervention.

Currently, very little is done in the way of file name translation. File names are converted to lower case unless literal-names has been set. Nothing is done about converting directories from one form to another, or making sure that the target file name is legal for a given system.

1.3. File Transfer

When running MAINKERMIT in local mode, some information is printed during the course of a file transfer. When a File Header packet is received or sent, the file name is printed. During the transfer, a dot is printed for every five Data packets. Table 1–1 lists other information shown.

Table 1–1. Information Displayed during File Transfer
. Five Data packets
Z End of file
S Short packet received
N NAK received
T Timeout
C Checksum Error

The keyboard is not active during the transfer, except for normal operating-system specific interrupts, such as CTRL-C or CTRL-T.

It is possible to abort a MAINKERMIT file transfer by typing the keyboard interrupt character (CTRL-C on many systems).

1.4. Operation

The MAINKERMIT default prompt is MAINKERMIT>, indicating that Kermit is waiting for a command. This prompt can be changed by the user to minimize confusion when switching from one system to another. In general, a command line is a command verb followed by an optional list of arguments, separated by spaces. Commands can be typed in from the keyboard, or taken from a file (see the TAKE command, Section 2.11). When MAINKERMIT is first started, the file kermit.ini is looked for on the current directory, and if present, commands are executed from it. Command files can be nested.

MAINKERMIT is slightly different from most other Kermits in that file transfer requests can be queued. The TEXT, PTEXT, and DATA commands allow the user to enter such a request and specify the file type. The SEND or GET command starts the transfer of the queue. It is possible to distinguish between text and data files during transfer because File Attribute packets have been implemented. The user must note, however, that few other Kermits have implemented this feature. If the other Kermit does not support File Attribute packets, the file is still sent, but may be treated incorrectly.

MAINKERMIT can also be used in a mode similar to other Kermits, where the file type is set with SET FILETYPE and file names are specified in the SEND command.

Chapter 2 describe the commands to MAINKERMIT in detail.


previous   next   top   contents   index   framed top   this page unframed

MAINKERMIT User's Guide, Chapter 1