Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!mailrus!tut.cis.ohio-state.edu!osu-cis!killer!tness7!bellcore!faline!thumper!ulysses!terminus!rolls!mtuxo!mtfmi!dbrod
From: dbrod@mtfmi.UUCP (D.BRODERICK)
Newsgroups: comp.lang.prolog
Subject: screen control
Keywords: screen control tput character based
Message-ID: <701@mtfmi.UUCP>
Date: 26 May 88 19:18:06 GMT
Organization: AT&T, Middletown NJ
Lines: 79


If your version of Prolog does not have screen control predicates,
but you are familiar with the Unix(tm) tput(1) command 
(or willing to become so), there is a quick and dirty way to 
generate some character based screen control predicates.  
tput(1) makes use of the terminfo database to generate terminal 
specific escape sequences to control the screen.  For example, 
the following, invoked from the shell, will print out "hello" 
in standout mode:

tput smso; echo hello; tput rmso

As you can see, the argument names are intuitively obvious(?).
To use this information from Prolog, write a shell script 
called "get_tput" as follows:
--------------------------------------
echo "tput('$2',$1,'`tput -T$1 $2`')."
--------------------------------------
This is invoked, for example, as: 
	get_tput vt100 clear >> tput.pl
It is easy enough to use a for-loop to generate a prolog 
terminfo database for all the tput arguments/terminals you want.
For an interesting sight, cat the file. ("tput sgr0" sets to normal)
To use on a PC running an ansi.sys driver, generate a database 
for ansi and download.
To use: 
	consult('tput.pl'). 	and call 
	tput(clear).		, defined as:

tput(Cmd) :- tput(Cmd,_,EscSeq), atomic(EscSeq), write(EscSeq).
tput(Cmd) :- tput(Cmd,_,[Esc|Seq]), print_list([Esc|Seq]).
tput(Cmd) :- not tput(Cmd,_,_).

This assumes you have loaded info only for your current terminal.
The reason for the middle clause is that shell tput commands that
take more than one parameter return a sequence that needs further
parsing.  I have not written a general parser, but have done some
of these by hand.  In what follows, what looks like ^ followed by [ 
is actually a real Escape char (in case you retype this).

% cup - set cursor position.  this works for vt100 and ansi
tput(cup(Row,Col),att5425,['[',R1,';',C1,'H']) :- R1 is Row+1, C1 is Col+1.

% csr - change scroll region
tput(csr(Top,Bottom),att5425,['[',T1,';',B1,r]) :- 
	T1 is Top+1, B1 is Bottom+1.

% pln - set system function key  Not on many terminals
tput(pln(Key,Label,Command),att5425,
		['[',Key,';',Len,';0;0q',Label16,Command]) :-
	name(Command,CAscii),
	length(CAscii,Len),
	pad_atom(16,Label,Label16).

tput(user,att5425,'}'). % switch to user function keys
tput(system,att5425,'~'). % switch to system function keys

% tsl - write to status line
tput(tsl(Col),att5425,['7[25;',Col1,'H']) :- Col1 is Col + 8.

% auxiliary predicates

print_list([]).
print_list([X|Xs]) :- write(X), print_list(Xs).

pad_atom(Num,Atom,Padded) :-
	name(Atom,AAscii),
	length(AAscii,Len),
	Pads is Num - Len,
	pad_blanks(Pads,BString),
	append(AAscii,BString,PAscii),
	name(Padded,PAscii).

pad_blanks(0,[]).
pad_blanks(Num,[32|Blanks]) :-
	Num > 0,
	Num1 is Num-1,
	pad_blanks(Num1,Blanks).

% append/3 as usual