extract drive letter from dwgprefix

[dilek]

I need to extract drive letter after i got the path with dwgprefix and add file name.

(Setq DN (getvar "DWGNAME"))
  (Setq DNLEN (strlen DN))
  (Setq PXLEN (- DNLEN 4))
  (Setq PXNAME (substr DN 1 PXLEN))
  (Setq DWGPATH (getvar "DWGPREFIX"))
  (Setq LFNAME (strcat (substr DWGPATH 1 3) PXNAME ".txt"))
  (Setq FN (OPEN LFNAME "W"))
  (close FN)

It gives me

"error: bad argument type: streamp nil"

Can you help me?

[BlackBox]

The error you're receiving is due to attempting to Close a file that was never opened... If you step through your code, you'll see that your call to Open returns Nil, instead of the file descriptor you're expecting.

One reason for that to happen, is that you may not have write-access to create a new file in that particular location.



Here's one way to avoid the error:

(vl-load-com)

(defun c:FOO (/ _GetDriveLetter file)

  (defun _GetDriveLetter (path) (substr path 1 3))

  (if (setq file
             (open
               (strcat
                 (_GetDriveLetter (getvar 'dwgprefix))
                 (vl-filename-base (getvar 'dwgname))
                 ".txt"
               )
               "w"
             )
      )
    (progn
      ;;<-- do something
      (close file)
    )
    (prompt "\n** Unable to open new file ** ")
  )
  (princ)
)

** Error handling not provided.

[dilek]

Thank you so much. You were right. I change the location of the file was saved and it fixed the issue.

[BlackBox]

Thank you so much. You were right. I change the location of the file was saved and it fixed the issue.

You're welcome; I'm happy to help.