program
fileTest (fin, fout, myfout, input, output);
{
This program shows how to declare files and
how to read
from and write to them. Although you may define file types
it would be safer to use text or textfile for
the type.
}
var fin , fout, myfout : text;
myFileName : string;
x, y : integer;
begin
{
The assign statement links the internal file name with a
disk file name. file names need
to be in single quotes
These assign statements do not indicate
whether the
files will be read from or written to. They just make
the connections.
}
assign (fin, 'data.in');
assign (fout, 'data.out');
{
reset opens a file we want to read from.
It should exist before program is run.
}
{
rewrite opens a file we want to write to
It will be created if it doesn't
exist.
It will be written over if it does
exist.
Both statements move the file
pointer to the
beginning of the file.
}
reset (fin);
rewrite (fout);
{
In this class you should always ask the user for
the name of the input file. If the user does
not
provide a full path, the program assumes the
file
is in the directory where the executable is.
}
writeln ('please enter the name of your
output file with complete path' );
readln (myFileName);
writeln ('*', myfilename, '*');
assign (myfout , myFileName); { links internal filename with diskfile name
provided by
user
}
x := 379;
write (fout, x, ' ');
writeln (fout, x);
read(fin, y);
readln (fin, y);
writeln (fout, ' x is ', x);
close(fin);
(* programmer should close files although operating system may do it *)
close(fout); (* if you forget. Do not count on it. '*)
writeln (' this statement appears on the
screen');
rewrite (myfout);
writeln (myfout, ' this statement appears in
the file ' + myfilename );
writeln (' have a look in file ' ,
myfilename);
close (myfout);
end.