Read/Write to file on old IBM PS/2 in turbo pascal 5.5 - pascal

The Question: I recently acquired a 1989 IBM PS2 and I am trying move large files from my newer UNIX-based machine to this IBM via floppy. I have a bash script that splits my files into ~2MB chunks, now I am trying to write a pascal program to reconstruct these files after they have been transferred.
I am unable to find the correct read/write to file methods on this computer. I have tried various pascal tutorial sites, but they are all for newer versions (the site I followed with File Handling In Pascal). I am able to create an empty file (as described below), but I am unable to write to it. Does anyone know the correct pascal read and write methods for this type of computer?
I know this is an obscure question, so thank you in advance for any help you can give me!
The Details:
The current test code that creates a file correctly is this:
program testingFiles;
uses Crt, Win;
const FILE_NAME = 'testFile.txt';
var outFile : File;
begin
writeln('creating file ...');
Assign(outFile, FILE_NAME);
rewrite(outFile);
end.
This is some test code that does not work, the method's append() and close() could not be found:
program testingFiles;
uses Crt, Win;
const FILE_NAME = 'testFile.txt';
var outFile : File;
begin
writeln('creating file ...');
Assign(outFile, FILE_NAME);
append(outFile);
writeln('this should be in the file');
close(outFile);
end.
This is an alternative that also did not work, the writeln() method only ever prints to the terminal. But otherwise this does compile.
program testingFiles;
uses Crt, Win;
const FILE_NAME = 'testFile.txt';
var outFile : File;
begin
writeln('creating file ...');
Assign(outFile, FILE_NAME);
rewrite(outFile);
writeln('this should be in the file');
close(outFile);
end.
The system: As was previously mentioned, this is a 1989 IBM PS2.
It has Windows 3.0 installed and can also run DOS and MS-DOS terminals.
It has Microsoft SMARTDrive Disk Cache version 3.06
It has Turbo Pascal 5.5 installed and I am using turbo as my command line pascal editor. (the readme was last updated in 1989)
It has Turbo debugger 1.5 installed.
Again, I know this is an obscure question, so thank you in advance for any help you can give me!

My Pascal memory is VERY rusty... but as other have pointed out, here is what you should consider:
program testingFiles;
uses Crt, System;
//No need of importin Win Win is for Windows enviorment, however I'm not sure if you need to use System, Sysutils or was there a Dos class???
const FILE_NAME = 'testFile.txt';
var outFile,inFile : File;
begin
writeln('creating file ...');
Assign(outFile, FILE_NAME);
rewrite(outFile);
//Now Open the first chunk of the file you want to concatenate
AssignFile(inFile, "fisrt_chunk.dat");
reset(inFile);
while not eof(inFile) do
begin
readln(inFile, s);
writeln(outFile,s);
end;
close(inFile);
end.
I don't have Turbo/Borland Pascal installed any longer so I couldn't compile it myself, no promise that it will work it is more like an idea:
Key thing to remember, readln and writeln will ALWAYS add a return at the end of the string/line, read and write on the other hand will leave the cursor wherever it is without jumping to a new line.

Here's some old Delphi code that should be at least close to syntax-compatible that will give you the gist of copying a file (with limited error checking and resource handling in case of error - I'll leave that as an exercise for you). It works to copy both binary and text content.
program Project2;
uses
SysUtils;
var
NumRead, NumWritten: LongInt;
pBuff : PChar;
SrcFile, DstFile: File;
const
BuffSize = 2048; // 2K buffer. Remember not much RAM available
InFileName = 'somefile.txt';
OutFileName = 'newfile.txt';
begin
NumRead := 0;
NumWritten := 0;
AssignFile(SrcFile, InFileName);
AssignFile(DstFile, OutFileName);
// Allocate memory for the buffer
GetMem(pBuff, BuffSize);
FileMode := 0; // Make input read-only
Reset( SrcFile, 1 );
FileMode := 2; // Output file read/write
Rewrite( DstFile, 1 );
repeat
// Read a buffer full from input
BlockRead(SrcFile, pBuff^, BuffSize, NumRead);
// Write it to output
BlockWrite(DstFile, pBuff^, NumRead, NumWritten);
until (NumRead = 0) or (NumWritten <> NumRead);
// Cleanup stuff. Should be protected in a try..finally,
// of course.
CloseFile(SrcFile);
CloseFile(DstFile);
FreeMem(pBuff);
end.
The above code compiles under Delphi 2007 currently (the oldest version I have installed). (See the note below.)
As a side note, this was from an archived version of some code I had that compiled both for 16-bit Delphi 1 and was extended to also compile under 32-bit Delphi 2 back in the mid-to-late 90s. It's still hanging around in my source repositories in an old tagged branch. I think I need to do some pruning. :-) I cleaned it up to remove some other functionality and removed a lot of {$IFDEF WIN32} ... {$ELSE} ... {$ENDIF} stuff before posting.)

Related

Delphi tmediaplayer don't play mp3 file with "strange" cover image embedded

I have developed a mp3 player with Delphi (XE) using the BASS library.
Due to certain reasons, I want to remove the BASS libraries and want to use the TMediaPlayer component in Delphi (also want to "move" the project to Delphi 10 Seattle).
Now I found out that some of my mp3 files have a "strange" jpg image embedded.
Means, that the Delphi components run into an error due to the image.
With long time debugging I can say the following:
try
mplMain.FileName := CurrentSong;
progbSong.Max := mplMain.Duration;
lblDuration.Text := DurationToString(mplMain.Duration);
PlayClick(Self);
except
on E: Exception do
begin
FMX.Dialogs.MessageDlg('Cannot play song: ' + CurrentSong + #10 + #13 +
'Reason: ' + E.Message,
TMsgDlgType.mtWarning, [TMsgDlgBtn.mbOK], 0,
procedure(const AResult: TModalResult)
begin
MediaNext;
end
);
end;
end;
This line:
mplMain.FileName := CurrentSong;
causes the problem.
Diving deeper in debugging it comes to here:
FMX.Media library:
procedure TMediaPlayer.SetFilename(const Value: String);
...
FMedia := TMediaCodecManager.CreateFromFile(FFileName);
...
At the end it ends up in FMX.Media.Win:
constructor TWindowsMedia.Create(const AFileName: string);
...
HR := FGraphBuilder.RenderFile(PChar(AFileName), nil);
...
When the line
HR := FGraphBuilder.RenderFile(PChar(AFileName), nil);
is called, in debug mode, the program just returns to the IDE.
In runtime mode, nothing happens. No error message, just "nothing".
As you can see, I wrapped the related line into a try...except block, but no error is raised. The program/player doesn't continue.
That's very bad for me, because I wanted to catch this "special case" and log the affected mp3 files to a logfile so that I can change the embedded image.
I found out that it is only caused by some images. Maybe they are "somehow corrupt", but shown in all other players.
When I remove the image and embed a "new" one and save the file, everything is fine and the TMediaPlayer can play the file.
How can I catch this certain kind of "error" to get the list of affected files?
I got it managed now.
Only in debug mode the application/player is exited without any thrown error and I find myself back in the IDE.
During runtime the try...except block works, when I chose an "affected file" manually. For the case that one file is played ("good one") and the next file is a "bad one", I had to change my "MediaNext" procedure. In this procedure I also had a try...except block when the filename was associated to the TMediaPlayer, but I just had set a bool variable for further use and didn't "jump" to the next file.
The code just was:
try
mplMain.FileName := CurrentSong;
except
on E:Exception do
SongNotPlayable := true;
end;
Here I can implement a routine to log the affected mp3 files into a logfile and then jump to the next file (if exists). :-)
Thanks again to all!

SelectDirectory does not include drives on some machines

The following code gets different results on different machines. One machine just gives the desktop folder (not desired) the other gives the desktop folder and Computer, mapped drives (desired).
procedure TForm1.Button1Click(Sender: TObject);
var
Directory : String;
begin
FileCtrl.SelectDirectory('Caption', 'Desktop', Directory, [sdNewUI, sdShowEdit]);
end;
One one machine it gives:
On another it gives:
This feels like a windows setting, but I am not sure where to start. Using Delphi XE, Windows 10.
Any thoughts are appreciated. Thanks for your time.
Workaround
Use a TFileOpenDialog instead*.
Set FileOpenDialog1.Options:= [fdoPickFolders,fdoPathMustExist]
Now you have a dialog that:
Always works.
Allows copy paste
*) Not to be confused with the TOpenDialog, which does not allow you to only select folders.
Solution for Windows XP
Note that the new TFileOpenDialog only works for Vista and above.
Your program will not work on XP if you include this control.
If you start the dialog on XP it will generate an EPlatformVersionException.
You may want to use the following code instead if you want to be backward compatible:
uses JclSysInfo; //because you have XE use JCL.
...
var
WinMajorVer: Integer;
Directory: string;
FileDialog: TFileOpenDialog;
begin
WinMajorVer:= GetWindowsMajorVersionNumber;
if WinMajorVer < 6 then begin //pre-vista
//To show the root Desktop namespace, you should be setting the Root parameter to an empty string ('') instead of 'Desktop'
FileCtrl.SelectDirectory('Caption', '', Directory, [sdNewUI, sdShowEdit]);
end else begin
FileDialog:= TFileOpenDialog.Create(self);
try
FileDialog.Options:= [fdoPickFolders,fdoPathMustExist];
if FileDialog.Execute then Directory:= FileOpenDialog1.FileName;
finally
FileDialog.Free;
end;
end;
Result:= Directory;
end;
Recommended reading:
detect windows version
EDIT
FileCtrl.SelectDirectory('Caption', 'Desktop', Directory, [sdNewUI, sdShowEdit]);
The 'Desktop' goes into the Root parameter, which is handled like so:
...
SHGetDesktopFolder(IDesktopFolder);
IDesktopFolder.ParseDisplayName(Application.Handle, nil,
Root, Eaten, RootItemIDList, Flags);
...
Here's what MSDN for IDesktopFolder.ParseDisplayName has to say:
pszDisplayName [in]
Type: LPWSTR
A null-terminated Unicode string with the display name. Because each Shell folder defines its own parsing syntax, the form this string can take may vary. The desktop folder, for instance, accepts paths such as "C:\My Docs\My File.txt". It also will accept references to items in the namespace that have a GUID associated with them using the "::{GUID}" syntax.
Note that the documentation states that the desktop folder will accept paths and guids. It does not accept 'Desktop'. Because that's neither.
The fact that 'Desktop' as a root works on one system but not another is some undocumented fix made in an older/newer version of the IDesktopFolder interface.
Technical solution
Use '' as a 'root' as shown in my code above.
Obviously SelectDirectory is a really bad design by Microsoft that should never be used. It just sucks in so many ways. I recommend it not be used whenever possible.

Open file in OS X

In Delphi, I would like to open a file in OS X. My approach is as follows:
const
Filename = 'test.bmp';
procedure SaveAndOpen;
begin
Chart.SaveToBitmapFile(Filename);
{$IFDEF MSWINDOWS}
ShellExecute(0, 'open', Filename, '', '', SW_Normal);
{$ELSE}
_System(Filename);
{$ENDIF}
end;
But nothing happens. What am I doing wrong?
This article from Embarcadero's Malcolm Groves covers this topic: Opening files and URLs in default applications in OS X.
In summary, all you need is this:
uses
Macapi.Appkit, // for NSWorkspace
Macapi.Foundation; // for NSSTR
....
var
Workspace: NSWorkspace; // interface, no need for explicit destruction
....
Workspace := TNSWorkspace.Create;
Workspace.openFile(NSSTR(FileName));
For sake of completeness, should you wish to open a URL rather than a file, then you call openURL instead:
Workspace.openURL(NSSTR(URL));
Regarding your Windows code, I would recommend not using ShellExecute. That function does not have reasonable error reporting. Use ShellExecuteEx in its place.
And finally, you should probably abstract this functionality away so that it can be re-used by other parts of your program. You want to write that IFDEF as few times as possible.
You must add the open verb like so
_System(PAnsiChar('open ' + Filename));

Lazarus(Pascal) RunError(5)

My program exits with RunError(5), which would suggest that it can't access the file, which it should be able to. I have checked and the file is used as it should be, the file isn't read-only, etc. What the program does is, it creates a .dat file if one doesn't exists and uses it for saving stuff. If I run the program and the file doesn't exist, the file is created, but after that, in the same execution, the program won't access the file. This ONLY happens if the file was created in the current execution.
This is the way in which the procedures are called(the code is quite long but I am giving you the first few lines, where the error occurs):
fileName := 'labSave.dat';
CreateFile;
assign(labyrinthFile,fileName);
writeln(CheckFileSize);
and then there is each of the procedures:
procedure Initialize;
begin
fileName := 'labSave.dat';
assign(labyrinthFile,fileName);
end;
procedure CreateFile;
begin
if not FileExists(fileName) then FileCreate(fileName);
end;
function CheckFileSize: integer;
begin
reset(labyrinthFile);
CheckFileSize := FileSize(labyrinthFile);
close(labyrinthFile);
end;
According to Lazarus forum (http://forum.lazarus.freepascal.org/index.php?topic=4936.0):
Runtime Error 5 means Access denied. The file maybe readonly and you
use the wrong (default) filemode, or you try to re-open the file with
a new filehandle without having closed it before (somewhere in the
while and repeat loops possibly you assignfile more then once, then
the reset fails?).
If I recall correctly now, the workflow should be as follows for create:
AssignFile(f, filename); Rewrite(f); CloseFile(f);
and for existing file:
AssignFile(f, filename); Reset(f); CloseFile(f);
Seeing other mistakes found in your code through questions in comments, I strongly suggest you to devote more time to debugging and when such errors happen - strip out ALL of the irrelevant code and check your code design for cases like above (assigning file before creating it, etc.).

Do Windows shortcuts support very long argument lengths?

I am trying to create a shortcut (on the Desktop) that contains a long argument string (> MAX_PATH).
The MSDN documentation clearly states that for Unicode string the string can be longer than MAX_PATH.
The resulting shortcut is cut exactly after MAX_PATH characters (that is the Path + the Arguments).
Is there something wrong with my implementation or is this some Windows limitation?
procedure CreateShortcut(APath: WideString;
AWorkingDirectory: WideString; AArguments: WideString; ADescription: WideString;
ALinkFileName: WideString);
var
IObject : IUnknown;
ISLink : IShellLinkW;
IPFile : IPersistFile;
begin
IObject := CreateComObject(CLSID_ShellLink);
ISLink := IObject as IShellLinkW;
ISLink.SetPath( PWideChar(APath));
ISLink.SetWorkingDirectory(PWideChar(AWorkingDirectory));
ISLink.SetArguments( PWideChar(AArguments));
ISLink.SetDescription( PWideChar(ADescription));
IPFile := IObject as IPersistFile;
IPFile.Save(PWideChar(ALinkFileName), False);
end;
PS: OS is Windows XP (and above).
It turns out that this issue is in fact solely a limitation in the Explorer shell dialog. The generated shortcut file does not have a 260 character limitation. It's simply that the dialog refuse to display a Target with more characters than that. Presumably it calls GetPath with a fixed length buffer.
procedure TForm11.Button1Click(Sender: TObject);
var
sl: IShellLinkW;
pf: IPersistFile;
begin
CoCreateInstance(CLSID_ShellLink, nil,
CLSCTX_INPROC_SERVER, IID_IShellLinkW, sl);
sl.SetPath('c:\desktop\test.bat');
sl.SetWorkingDirectory('c:\desktop\');
sl.SetArguments(PChar(StringOfChar('x', 300)+'_the_end'));
pf := sl as IPersistFile;
pf.Save('c:\desktop\test.lnk', False);
end;
My test.bat looks like this:
echo %1> test.out
The resulting test.out goes right the way to _the_end!
Thanks all who contributed to this thread - it helped me immensely.
However, if I may, I would like to add the below information I discovered in crafting my solution:
On Windows 7 Enterprise ~SP1, it would seem that using VBS to create the shortcut there is still a limit on maximum characters in (at least) the arguments field. I tested up to 1023 chars before it got trunicated. I presume the same limit would apply to the Delphi method likewise.
On Windows XP Professional ~SP3, while the VBS method will create a shortcut longer than 260 characters (lnk file contains the data), it seems to trunicate it at about this number when executing it.

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