Re: Need help launching application in MCL (from a data file)

[moon (David A. Moon)]

> Date: Thu, 5 Nov 92 16:27:14 EST
> From: dmg@goldilocks.LCS.MIT.EDU (David Goodine)
> 
> I'm trying to write some code that will take a pathname for an arbitrary
> file and launch the application that created the file.  I've managed to
> launch an application explicitly, but can't figure out how to get the
> mapping from the CREATOR of the file to the application (which the
> finder seems to do internally).
> 
> The inside-mac documentation here has been no help... it seems to happen
> magically somewhere between the finder and the process manager...

It is documented, but only for system 7.  You want the PBDTGetAPPL trap.  Try 
the following:

;;; -*- Mode: Lisp; Package: CCL -*-

(in-package CCL)

;;; A handy subroutine, only works in system 7
;;; Returns the pathname of the application or nil if not found on any volume
;;; Several undocumented errors can occur, I hope I found them all
(defun application-pathname (signature)
  (rlet ((pb :dtpbrec)
         (iopb :hparamblockrec))
    (%stack-block ((name 256)) 
      (setf (rref iopb :hparamblockrec.ioCompletion) (%null-ptr)
            (rref iopb :hparamblockrec.ioNamePtr) name)
      (loop for volume-index from 1 do
        (setf (rref iopb :hparamblockrec.ioVolIndex) volume-index
              (rref iopb :hparamblockrec.ioVRefNum) 0)
        (let ((err (#_PBHGetVInfo iopb)))
          (unless (zerop err)
            (if (= err #$nsvErr)
              (return-from application-pathname nil)
              (error "_PBHGetVInfo error #~D" err))))
        (setf (rref pb :dtpbrec.ioCompletion) (%null-ptr)
              (rref pb :dtpbrec.ioNamePtr) name
              (rref pb :dtpbrec.ioVRefNum)
               (rref iopb :hparamblockrec.ioVRefNum))
        (let ((err (#_PBDTGetPath pb)))
          (unless (zerop err)
            (unless (= err #$wrgVolTypErr)
              (error "_PBDTGetPath error #~D" err))))
        (setf (rref pb :dtpbrec.ioIndex) 0
              (rref pb :dtpbrec.ioFileCreator) signature)
        (let ((err (#_PBDTGetAPPL pb)))
          (cond ((zerop err)
                 (setf (rref iopb :hparamblockrec.ioDirID)
                       (rref pb :dtpbrec.ioAPPLParID))
                 (return-from application-pathname (%path-from-iopb iopb)))
                ((and (/= err #$afpItemNotFound) (/= err #$fnfErr))
                 (error "_PBDTGetAPPL error #~D" err))))))))