Allegro CL FAQ: 4.11: Allegro CL jLinker add-on

4.11: Allegro CL jLinker add-on

Q 4.11-1) Why does a call to jlinker-init with a non-nil value for debug fail? (I am running Windows 98.)

Q 4.11-1) Why does a call to jlinker-init with a non-nil value for debug fail? (I am running Windows 98.)

A 4.11-2) jlinker-init calls javatools.jlinker::run-java, the source for which is shown in the file [Allegro Directory]/jlinker/jl-config.cl. The definition for that function contains the line:

    (if debug "cmd /c start /wait /b java.exe" "javaw.exe")

so if the debug is true, a call is made to cmd. However, cmd is not defined on Windows 95/98. Instead command.com is defined, and the line in the definition of javatools.jlinker::run-java should be

    (if debug "command.com /c start /wait /b java.exe" "javaw.exe")

There seems to be no reliable way to determine at run-time the actual version of the Windows Operating System being run, nor whether cmd or command.com is the correct command to use. If you are running Windows 95/98, you can edit jl-config.cl to use command.com rather than cmd with the following three steps. Then the next time you use Allegro CL, the revised definition of will be used and you can call jlinker-init with debug true.

Copy jl-config.cl to jl-config-orig.cl
Add the following code to the end of the file jl-config.cl, after the last |#, and save the file with the changes.
Be sure that you load jl-config.cl when before using jLinker. (This is recommended in general because the file initializes certain variables appropriately.)

(in-package :javatools.jlinker)
(defun run-java (&optional debug lport lhost jport jhost &rest more)
  (let* ((op-val #+unix      "java"
		 #+mswindows 
                 ;; replaced cmd with command.com in next line so it runs on
                 ;; Windows 95/98:
		 (if debug "command.com /c start /wait /b java.exe" "javaw.exe")
		 )
	 (class javatools.jlinker::*java-link-base-class*)
	 (cmdl (append (list op-val class)
		       (when lport (list "-lport" (format nil "~A" lport)))
		       (when lhost (list "-lhost" lhost))
		       (when jport (list "-jport" (format nil "~A" jport)))
		       (when jhost (list "-jhost" jhost))
		       (when debug (list "-debug"))
		       (mapcar #'(lambda (m) (format nil "~A" m)) more)
		       ))
	 (command 
	  #+mswindows (format nil "~{~A ~}" cmdl)
	  #+unix
	  (if *jlinker-unix-vector-p*
	      (make-array (1+ (length cmdl)) 
			  :initial-contents (cons (car cmdl) cmdl))
	    (format nil "~{~A ~}" cmdl))
	  )
	 (log 
	  #+mswindows (and debug (jlinker-slot :java-out)
			   (concatenate 
			    'string (jlinker-slot :java-out) ".log"))
	  #+unix nil
	  )
	 (elog (when log 
		 (concatenate 'string (jlinker-slot :java-out) "e.log")))
	 (show (if (and debug (null log)) :showna :hide))
	 )
    (set-java-paths)
    (when log (jlinker-slot :java-out :wrap))
    (jcollect-pid
	 command
	 :output log
	 :if-output-exists :supersede
	 :error-output elog
	 :if-error-output-exists :supersede
	 :show-window show
	 :wait nil)))

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