1. Computer Science II
Second With files

2. Goals for today Review file commands from last class.
Be able to read a program that uses files
Be able to fix a program that uses files
Be able to write a program that uses files

3. Dry run the following code
program fileOfStuff; {5 pts}
type
RecordType= record
a,b:integer;
c:real;
end;
filetype = file of Recordtype;
var
Shuttle:Recordtype;
fyle:filetype;
count:integer;
begin
assign(fyle,'stuff.dta');
rewrite(fyle);
for count:= 10 to 13 do
Shuttle.a:= count DIV 2;
Shuttle.b:= count mod 3;
Shuttle.c:= (shuttle.a+shuttle.b)/2;
write(fyle,shuttle);
close(fyle);
reset(fyle);
while not eof(fyle) do
read(fyle, shuttle);
if shuttle.a mod 2 = 0 then writeln(shuttle.a:5, shuttle.b:5, shuttle.c:6:2);
readln;
End.
Dry run the following code

4. philephix.pas on the class website
program fix’nFile; {This program is supposed to create a file of 1000 random numbers then show them on the screen} type file = file of integer; var total:integer; begin assign(file, ‘numb.skl’); reset(file); for count := 1 to file do readln(file, total); end; for count = 1 to EondOfFile do writeln(file) end.
Fix File
philephix.pas on the class website

5. File review Declare Assign(Numfile, ‘stuff.dta’); Rewrite(Numfile);
Type
Filetype = file of integer;
Var
Numfile:Filetype;
Ties the file variable to the file on the disk.
Creates (erases) a file to be written to.
Puts information into a file.
Puts an EOF marker in the file if adding to the file, and releases the file pointer.
Opens a pre-existing file
Checks for the end of the file
Returns the number of ‘chunks’ in the file.
Moves the file pointer to the ‘Position’ spot on the file
Used to copy information from a file.
See above.
Declare
Assign(Numfile, ‘stuff.dta’);
Rewrite(Numfile);
Write(Numfile, variable);
Close(Numfile);
Reset(Numfile);
Eof(filename)
FileSize(Filename)
Seek(Filename,Position);
Read(Numfile,Variable);

6. First File Program 1) Input an unknown number of names into a file.
Show them from the file.
2) Input: An unknown number of integers.
Process:
Using a file for storing the information, find the total, average, and the number of values within 3 of the average of the values.
Output:
A chart of the numbers entered.
The average
The number of values within three of the average.
Example:
If you enter:
3, 10, 17, 12, 8
Numbers: 3 10 17 12 8
The average = 10
The number within 3 of the average = 3
3) Add a save and load option to the life program.