Reading,extracting and saving values in a file as an integer

[Appjacker]

Working on a program that needs to open a file, read the contents which is a number, save the content as an integer in the program, edit the number by one and then save in the number in the file once more.

[pritaeas]

Pascal or Delphi? What do you have so far, and where are you stuck?

[Appjacker]

Pascal... Have nothing thus far but this. But it was only created as a test extract.
Application.Initialize; Application.CreateForm(TForm1, Form1); Application.Run; d:=1; Assign(Counter,'C:\check.txt'); Rewrite(Counter,d); close(counter); d:=d+1;
It all seems basically wrong and am pretty much stuck from the start so all help will do.

[pritaeas]

What you posted is Delphi code, but those functions still work. The following is a modified example from Delphi's Help to write a value to a text file:

var
  F: TextFile;
  d: Integer;
begin
  d := 1;
  AssignFile(F, 'C:\check.txt');
  Rewrite(F);
  Writeln(F, IntToStr(d));
  CloseFile(F);
end;

[Appjacker]

Now to extract it from the file, put in array then increase the value by one and finally save it back to the file.

[pritaeas]

Try it. You can find lots of examples in the help file.

[Appjacker]

I get run time error(104). Here's code:
`

var User: array of UserRecord;
     var
    F: TextFile;
    d,count: Integer;
   Procedure readcounter;
begin
    AssignFile(F, 'C:\check.txt');
    Rewrite(F);
    while not eof(f) do
    readln(f,d);<----- error pointed to here
    closefile(f);
    end;
    Procedure editcounter;
    begin
    d:=d+1;
    assign(f, 'C:\check.txt');
    rewrite(f);
    writeln(f, IntToStr(d));
//Writeln(F, IntToStr(d));
    CloseFile(F);
    end;
 Procedure checkdata;
 begin
 for count:= 1 to (d) do
 with User[d] do
 if (username = Edit1.text) and (useremail = edit3.text) and (Rname = edit4.text) and (Remail = edit6.text) then
 showmessage('Certain Fields are already taken please re-check and try again')
 else
   username := Edit1.text;
   userpassword := Edit2.text;
   useremail := edit3.text;
   Rname := Edit4.text;
   Rpassword := Edit5.text;
   Remail := Edit6.text;
   application.terminate;
 end;
{ TForm1 }


{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
begin
  readcounter;
  checkdata;
  editcounter;
end;

`

[pritaeas]

Rewrite sets the file pointer to the beginning of the file for writing. Since you want to read, use Reset.

[Appjacker]

now its saying raised exception class'External: SIGSEGV'. Then points to line in control.inc
if TMethod(@Self.GetTextBuf).Code = Pointer(@TControl.GetTextBuf)

[pritaeas]

Step through it with the debugger and see where it fails in your code.

[Appjacker]

how does one go about that...

[pritaeas]

http://www.youtube.com/watch?v=amZIKVk7_-U

[Appjacker]

Didn't help... Really couldn't understand wat the man was saying at all

[Appjacker]

I'm going through and it points to this in my lpr

`begin<-------- pointed to here
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;

end.`

[Appjacker]

stepped over it and the assembler popped up with this:
System_FPC_CPUINIT (7)
System_FILLCHAR$formal$LONGINT$BYTE

[Appjacker]

Stepped again and got this:
fpc_initializeunits
and then pointed to this line saying:
0040c7A3 8b1dd0bd5600 mov

[Appjacker]

Step over then it points to line 2 in lpr

[pritaeas]

Set a breakpoint (using F5) on the first line in readcounter and start from there.

[Appjacker]

ok did that, didn't work but i think i've found the main cause of the problem by taking apart and executing each procedure individually. See below:

  Procedure checkdata;
 begin
 for count:= 1 to (d) do
 with User[d] do
 if (username = Edit1.text) and (useremail = edit3.text) and (facebookname = edit4.text) and (facebookemail = edit6.text) then
 begin
 showmessage('Certain Fields are already taken please re-check and try again');
 end
 else
   username := Edit1.text;
   userpassword := Edit2.text;
   useremail := edit3.text;
   facebookname := Edit4.text;
   facebookpassword := Edit5.text;
   facebookemail := Edit6.text;
   application.terminate;     

`
now the block that is causing the problem is

username := Edit1.text;
   userpassword := Edit2.text;
   useremail := edit3.text;
   facebookname := Edit4.text;
   facebookpassword := Edit5.text;
   facebookemail := Edit6.text;
   application.terminate;      
 end;`

Don't know what exactly is the problem, maybe a conversion needs to be done or data types changed or something. Would love to dabble with it now but i have to attend to stuff. But if you do know what to do let me know, Thanks.

[pritaeas]

for count:= 1 to (d) do with User[d] do

If User is an open array, then the count should be from 0 to d - 1. Apart from that, did you specify a length for the array using SetLength ?