-- card: 31988 from stack: in.5
-- bmap block id: 35406
-- flags: 0000
-- background id: 3858
-- name: DiskSpaceAvail
----- HyperTalk script -----
on HideObjects
  hide cd btn "Try It!"
end HideObjects

on ShowObjects
  show cd btn "Try It!"
end ShowObjects


-- part 6 (button)
-- low flags: 00
-- high flags: A002
-- rect: left=78 top=197 right=231 bottom=171
-- title width / last selected line: 0
-- icon id / first selected line: 0 / 0
-- text alignment: 1
-- font id: 0
-- text size: 12
-- style flags: 8192
-- line height: 16
-- part name: Try it!
----- HyperTalk script -----
on mouseUp
  put volumePath() into newVolume
  if newVolume = empty then exit mouseUp
  put DiskSpaceAvail(newVolume) into freeSpace
  answer freeSpace && "bytes (" & freeSpace div 1024 && "K) free on “" & newVolume & "”"
end mouseUp




-- part contents for background part 20
----- text -----
This XFCN returns the amount of free space (in bytes) on a disk.  It is functionally similar to HyperCard's "DiskSpace", except that it works with any mounted volume

To use this demo click on the "Try It!" button.
You will be presented with a dialog to select one of your mounted drives.

Calling syntax : DiskSpaceAvail(volumeName, <"noDialog:"errorGlobal>)
  VOLUMENAME: the path to the volume to check.


-- part contents for background part 38
----- text -----
10/50

-- part contents for background part 42
----- text -----
{ DiskSpaceAvail(volumeName «,“noDialog:”errorGlobal»)  }
{ XFCN to determin amount of free space on a volume, returns  }
{ the number of bytes free                          }
{}
{  brought to you by:  Anup Murarka      Eric Carlson    }
{            ALINK:  SKEPTIC      ALINK:  cyNic  }
{                  CIS:  76004,3356    }
{}
{        We are part of the Support Tools Development Group,  }
{        Apple Computer, Inc.  }
{}
{        please DO NOT contack Mac DTS for support of this code!  }
{}
{        please DO contact the authors for support of this code!  }
{}
{        Send comments, bug reports, requests to any of the above  }
{        E-mail addresses or to:}
{}
{              (one of us)          }
{              Apple Computer, Inc.    }
{              900 E. Hamilton, Ave.    }
{              Campbell, CA   95008    }
{              M/S 72-L          }
{}
{  Copyright:  © 1989, 1990 by Apple Computer, Inc., all rights reserved.  }
{}
{ written by Eric Carlson                    }
{ AppleLink:  cyNic                        }
{ modification history                       }
{       Date        Initials                  Comments                  }
{       ----        ------    ------------------------------------------------------  }
{    1/26/90        ec      first written                                  }
{    2/14/90      ec      general code cleaning                            }
{    5/31/90      ec      commented code further                          }
{    7/2/90      ec      fixed unsinged/signed conversion bug as per Tech note 157, changed version }
{                                  to 1.1      }
{}

unit DiskSpaceAvail;

interface

  uses
    HyperXcmd;

  procedure MAIN (paramPtr: XCmdPtr);

implementation

  procedure DiskSpaceAvail (paramPtr: XCmdPtr);
  FORWARD;

  procedure MAIN (paramPtr: XCmdPtr);
  begin
    DiskSpaceAvail(paramPtr);
  end;

  procedure reportToUser (paramPtr: XCmdPtr;
                  msgStr: str255);
{}
{ report something back to the user.  }
{ the last parameter (optional) to an external may contain }
 { "noDialog" or "noDialog:GlobalName".  GlobalName is the name }
 { of a HyperTalk global variable into which error messages will be }
 { placed.  we've decided to use this approach to avoid confusing }
{ an error message with a valid result being returned from an XFCN. }
{}
    var
      tempStr: str255;
  begin
{check the last param to see if the user requested that}
{ we suppress the error dialog }
    ZeroToPas(paramPtr, paramPtr^.params[paramPtr^.paramCount]^, tempStr);
    UprString(tempStr, true);
    if pos('NODIALOG', tempStr) = 0 then
  { no special error handling specified, throw up a dialog and return the error message }
      begin
        SendCardMessage(paramPtr, concat('answer "', msgStr, '"'));
        paramPtr^.returnValue := PasToZero(paramPtr, msgStr);
      end
    else if (pos(':', tempStr) > 0) then
  { requested global AND noDialog so we fill in the global and return empty }
      begin
        tempStr := copy(tempStr, pos(':', tempStr) + 1, length(tempStr));
                            { get the name of the HC global  to fill }
        SetGlobal(paramPtr, tempStr, PasToZero(paramPtr, msgStr));
                            { and fill it }
        paramPtr^.returnValue := PasToZero(paramPtr, '');  { return empty }
      end
    else
  { requested noDialog only so we return the error condition as the result }
      paramPtr^.returnValue := PasToZero(paramPtr, msgStr);
  end;  { procedure }

  function NumberToString (paramPtr: XCmdPtr;
                  num: LONGINT): Str255;
{ use the toolbox call rather than HC's }
    var
      tempStr: str255;
  begin
    NumToString(num, tempStr);
    NumberToString := tempStr;
  end;

  procedure reportResError (paramPtr: XCmdPtr;
                  errorNum: integer);
    var
      errMsg, tempName: str255;
  begin
    sysbeep(40);
    case errorNum of          { what caused the problem? }
      bdNamErr: 
        errMsg := 'Bad volume name.';
      extFSErr: 
        errMsg := 'External file system.';
      ioErr: 
        errMsg := 'I/O Error.';
      nsDrvErr: 
        errMsg := 'No such drive.';
      nsvErr: 
        errMsg := 'No such volume.';
      paramErr: 
        errMsg := 'You may not eject the default volume.';
      otherwise
        errMsg := concat('unexpected error #', NumberToString(paramPtr, errorNum));
    end;    { case }

    errMsg := concat('Sorry, ', errMsg);
    reportToUser(paramPtr, errMsg);
    { return the error message }
  end;    { function }

  function getParams (paramPtr: XCmdPtr;
                  var volToFind: str255): boolean;
    var
      numParams: integer;
      inputCh: str255;
  begin
    getParams := true;
    numParams := paramPtr^.paramCount;
    if (numParams < 1) or (numParams > 2) then
      begin
        getParams := false;
        reportToUser(paramPtr, 'DiskSpaceAvail(volumeName «,“noDialog:”errorGlobal»)');
        exit(getParams);
      end;
    MoveHHi(paramPtr^.Params[1]);
    HLock(paramPtr^.Params[1]);
    ZeroToPas(paramPtr, paramPtr^.Params[1]^, volToFind);
    HUnlock(paramPtr^.Params[1]);
    uprString(volToFind, true);
    if (volToFind = '?') or (volToFind = '') then
      begin
        getParams := false;
        reportToUser(paramPtr, 'DiskSpaceAvail(volumeName «,“noDialog:”errorGlobal»)');
        exit(getParams);
      end;
    if (volToFind = '!') then
      begin
        getParams := false;
        reportToUser(paramPtr, 'v1.1, © 1990 Apple Computer, Inc., by Eric Carlson');
        exit(getParams);
      end;
  end;    {GetParams}

  function validVolumeName (volumeName: str255): str255;
  { a volume name must have one (and only one) colon in it, as }
  { the last character }
  begin
    if pos(':', volumeName) = 0 then
      validVolumeName := concat(volumeName, ':')
    else
      validVolumeName := copy(volumeName, 1, pos(':', volumeName));
  end;

  procedure DiskSpaceAvail (paramPtr: XCmdPtr);
    type
      TwoIntsMakeaLong = record
          case integer of
            1: (
                long: LongInt
            );
            2: (
                ints: array[0..1] of integer
            );
        end;
    var
      theSpace: TwoIntsMakeaLong;
      getParamsOK: boolean;
      volToTest: str255;
      PB: HParamBlockRec;
      errorCode: OSErr;

  begin
  { fetch and validate the passed parameters}
    getParamsOK := getParams(paramPtr, volToTest);
    if not (getParamsOK) then
      exit(DiskSpaceAvail);

    volToTest := validVolumeName(volToTest);      { make sure the volume name is correct }

  { initialize parameter block.  Since volToTest is a full pathname, no other field is needed}
    zeroBytes(paramPtr, @PB, sizeOf(PB));
    PB.ioNamePtr := @volToTest;
    PB.ioVolIndex := -1;
    errorCode := PBHGetVInfo(@PB, false);

    if errorCode = noErr then
      begin
{ we must change the unsinged int returned by our PBH call to a signed long ourselves as the compiler }
{  will sign extend it and thus make it negative - see tech note 157 }
        theSpace.ints[0] := 0;                { clear the high word }
        theSpace.ints[1] := PB.ioVFrBlk;          { set the low word to our value }
        NumToString(theSpace.long * PB.ioVAlBlkSiz, volToTest);  { borrow our string var for a minute }
        paramPtr^.returnValue := PasToZero(paramPtr, volToTest);
      end
    else
      begin
        reportResError(paramPtr, errorCode);
        exit(DiskSpaceAvail);
      end;
  end;    { procedure FileExists}

end.  { unit FileExists}