Hi,

can someone of you tell me how to read from a file ?

see('sth.txt'),read(X),write(X),nl,seen.

doesn't seem to work.
how can i do this ?

Christoph

On Wed, 21 Nov 2001 15:27:46 +0100, Christoph Hermann

Maybe you should be a bit more specific on what doesn't
work and what is in sth.txt.  There is nothing wrong with
this program a such and it will work fine provided sth.txt
exists, can be accessed for reading and contains a valid
Prolog term terminated by a fullstop and blank character.
(your Prolog may be forgiving on the blank, but the standard
demands it).

If your sth.txt contains ordinary text, have a look at get0/1
for reading characters.

If you want a bit more modern code, have a look at open/3
and get_code/2.

        Regards --- Jan

that was the Problem thanks :)

Now i have another Problem...
Given the following Code:

test:-readline('bla.txt',3,X),write(X),nl.
readline(File,Linenumber,Result):-see(File),readtheline(Linenumber,Resul
t,0),seen.

readtheline(Linenumber,Result,Linenumber):-!.
readtheline(Linenumber,Result,Current):-Y is Current + 1,write('2 '),
read(X), readtheline(Linenumber,X,Y).

the Procedure readtheline/3 works fine, a part of the fact, that at the
end, while exiting the recursion it resets the Var "Result".

   Call: (11) readtheline(3, testline3, 3) ? creep
   Exit: (11) readtheline(3, testline3, 3) ? creep
   Exit: (10) readtheline(3, testline2, 2) ? creep
   Exit: (9) readtheline(3, testline1, 1) ? creep
   Exit: (8) readtheline(3, _G336, 0) ? creep
                            ^^^^^^

bla.txt looks like this:

testline1.
testline2.
testline3.
...

Any hints how i can avoid this ?
Christoph