GET20 (~3750 chars)

[towson at AMSAA.ARPA]

From:      David Towson (CSD) <towson at AMSAA.ARPA>

Giving credit where credit is due, I must emphatically state that I was only
a clerk (and occasional needler) in the development of the automatic FTP
programs for UNIX systems.  The mastermind was Ferd Brundick <fsbrn at brl-voc>
of the Army Ballistic Research Labs.  HE wrote the programs that automatically
run FTP.  All I did was write some shell scripts that use Ferd's programs, and
I also wrote the documentation file, part of which is appended below.  So since
it was Ferd who wrote the programs, I can safely agree wholeheartedly with
Rick Conn:  These programs are REALLY NEAT!


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                    AUTOMATIC FTP PROGRAMS FOR UNIX SYSTEMS



     These automatic FTP programs for UNIX systems provide a nearly effortless
way to transfer files from the public-domain archives on SIMTEL20 using the
InterNet File Transfer Protocol, FTP.  The principal "worker" in this
collection is the program GET20, a Bourne shell script written by Ferd Brundick
of the U.S. Army Ballistic Research Laboratory.  GET20 accepts inputs from the
keyboard, or more conveniently from another shell script, and then calls the
FTP program on the user's system and provides all needed inputs.  Three file
transfer modes are supported, ASCII, binary image, and binary in 8-bit bytes.
SIMTEL20 is a 36-bit word-size PDP-20 running the TOPS-20 operating system.
Therefore, only the ASCII and 8-bit-byte transfer modes will be useful for
obtaining files from the public domain archives, as the data in these files
must be unpacked from the 36-bit SIMTEL20 words and repacked for storage in
16 or 32-bit UNIX words.  The binary image transfer mode is provided only for
special applications.  GET20 can be (and has been) easily edited to allow
automatic retrieval of files from other machines that honor an anonymous FTP
login.  Once GET20 has been set in action, all aspects of the FTP process
happen automatically.

     There are currently five archives on SIMTEL20:

		MICRO:<CPM>
		MICRO:<SIGM>
		MICRO:<CPMUG>
		MICRO:<UNIX>
		MICRO:<PC-BLUE>

All files in <UNIX> are in ASCII.  Some files in <CPM>, <SIGM>, <CPMUG> and
<PC-BLUE> are in ASCII, while others are in ITS binary.  The general file-name
format for all archive files is:

		MICRO:<ARCHIVE_NAME.DIRECTORY_NAME>PROGRAM_NAME

GET20 has the device-name MICRO: built-in, but the other three parts of the
path-name must be supplied by the user.  Thus, a typical command-line for GET20
looks like this:

		get20 -a sigm.vol007 james.bond

or alternately,

		get20 -a sigm.vol007 james.bond new_name

The first form will transfer the file keeping the same name (in this case,
james.bond), and the second form will give the transferred file a new name on
the local system.  If you give the command "get20" (with no arguments), GET20
will display a usage statement.

     The REAL convenience of GET20 comes from driving it with one-liner shell
scripts that accept user input in VERY abbreviated form.  For example, the
one-liner "siga" , which obtains ASCII files from the <SIGM> archive, contains:

		get20 -a sigm.vol$*

To obtain the file of the previous example, a user need only type:

		siga 007 james.bond

If a user wants to do frequent ASCII transfers from the <CPM.MODEM7>
directory, the one-liner "m7a" (or some such name) having the form:

		get20 -a cpm.modem7 $*

can be used.  The user will then type only:

		m7a mdm730.asm

The possibilities are endless.


     NOTE:  The above is just a piece of the documentation file.  For the full
story, FTP the file MICRO:<UNIX.TOOLCHEST>AUTOFTP.DOC from SIMTEL20.


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Dave
towson at amsaa.arpa