Inside Macintosh: Interapplication Communication /

Chapter 2 - Edition Manager / Edition Manager Reference

Edition Manager Routines / Reading and Writing Non-Edition Files

CallFormatIOProc

Use the CallFormatIOProc function to call a format I/O function.

FUNCTION CallFormatIOProc (selector: FormatIOVerb; 
                           VAR PB:FormatIOParamBlock; 
                           routine: FormatIOProcPtr): OSErr;

selector

A format I/O verb (ioHasFormat, ioReadFormat, ioNewFormat, ioWriteFormat).

PB

A format I/O parameter block record.

routine

A pointer to a format I/O function.

DESCRIPTION

The Edition Manager calls a format I/O function whenever it needs to read from or write to an edition. The Edition Manager passes a format I/O parameter block as one of the parameters to a format I/O procedure. The format I/O parameter block is defined by this structure:

TYPE FormatIOParamBlock = 
   RECORD
      ioRefNum:      LongInt;       {reference number}
      format:        FormatType;    {edition format type}
      formatIndex:   LongInt;       {opener-specific enumeration } 
                                    { of formats}
      offset:        LongInt;       {offset into format}
      buffPtr:       Ptr;           {data starts here}
      buffLen:       LongInt;       {length of data}
   END;

SEE ALSO

See "Calling a Format I/O Function" beginning on page 2-68 for additional information.