Customizable hercules 3270 Logo

The initial welcome screen presented when a TN 3270 terminal connects 
to a hercules 3270 device can now be customized.

The customized logo is stored in a plain text file which contains 
positioning orders, attributes and variable substitutions.

hercules also contains a built-in logo should no suitable file be found.

Upon startup, hercules will first look for a file named "herclogo.txt" in
the current directory.

The name of the logo file can also be specified as a startup option by
using the '-b' flag.

Additionally, the file may also be specified by using the 'HERCLOGO' 
configuration statement.

(NOTE : The statement was previously LOGOFILE, but LOGOFILE has been
 deprecated).

The file may also be specified by using the 'HERCLOGO' environment
variable.

The file to be used can also be specified at run time using the
'HERCLOGO' panel command.

Each line in the file represent either an order or a plain text line.

The orders are as follows :

@SBA X,Y
Position the current buffer position to Row X col Y (X and Y start at 0)

@SF [H][P]
Set the Highlight and/or Protected attribute

@NL
Forces going to the next line

@ALIGN NONE|LEFT|RIGHT|CENTER
Specified the text alignement (relative to the left and right borders of the 
terminal). When ALIGN is other than "NONE", a new line is automatically
inserted after each line of text. If ALIGN is "NONE", then the text will
be written without skipping to the next line.

It is also possible to embbed substitution variables in outgoing text.
Substition is indicated by enclosing the variable name between $( and )

The following variables are defined in that environment :

VERSION : The hercules version
HOSTNAME : The host name on which hercules is running
HOSTOS : The host operating system
HOSTOSREL : The Host operating system release
HOSTOSVER : The host operating system version
HOSTARCH : The host architecture
HOSTNUMCPUS : UP (for 1) or MP=X (for more than 1)
LPARNAME : The LPAR name specified in the configuration file
CCUU,ccuu,CUU,cuu : Various forms of the device number of the terminal
CSS : The Logical Channel Subsystem Set or Channel Set for the terminal
SUBCHAN : The Subchannel number for the terminal

Additionally, it is also possible to specify environment variable names.

The file 'herclogo.txt' is provided in the distribution as a sample template.
It reflects the contents of the built-in logo.

Ivan Warren 3/1/2006
