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 is safer to declare them as textfile

}

var fin , fout, myfout : textfile;

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);

writeln (' got here 1 ');

{

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);

writeln (' got here 2 ');

read(fin, y);

writeln (y);

writeln (' got here 3 ');

readln (fin, y);

writeln (' got here 4 ' );

writeln ( y);

writeln (fout, ' x is ', x);

writeln (' got here 5 ');

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.