LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

scrambled characters in response of G http-server on linux

Hello.

I am trying to set up the G Web Server from the Internet Toolkit 5.0 in LabVIEW 6.1 on Red Hat Linux 8.0. In general, that web server seems to be running.
It is configured to listen for connections on port 8080. So when I access http://localhost:8080/ with my browser it shows up a directory listing of the www-root, but all files and dirs only in one line w/o linefeed.
See attached Gwebroot.png
Navigating through the files and dirs shows only web related contents but none of my VIs. Clicking on "index.htm" brings the G Web Server welcome screen just as expected. I can navigate through the example pages, but every time I click on a VI example I only get unreadable gibberish, like a
s my browser reads the binary contents of the VI as ASCII characters. Same symptoms as discussed in Document ID: 0VJC8SSG but solution apparently not applicable.
A remote computer on Win32 or Linux behaves the same.
I already have ITK and proper VI running on Win32 and it works fine, also viewing that VI with Linux remote machine. But hosting same VI on Linux G web server only shows scrambled ASCII characters.
See attached Gexppi.png and Gproj2.png

What am I doing wrong?
I'm out of ideas. Need help!

Regards, Ralf Richter
Download All
0 Kudos
Message 1 of 2
(2,309 Views)
rrichte1 wrote:

> Hello.
>
> I am trying to set up the G Web Server from the Internet Toolkit 5.0
> in LabVIEW 6.1 on Red Hat Linux 8.0. In general, that web server seems
> to be running.
> It is configured to listen for connections on port 8080. So when I
> access http://localhost:8080/ with my browser it shows up a directory
> listing of the www-root, but all files and dirs only in one line w/o
> linefeed.
> See attached Gwebroot.png

Sounds like a little problem with the line termination. On Windows the
line termination is a carriage return/line feed. On Unix it is only line
feed.
Now HTML requires in fact as line termination and the way this
is probably solved is that a routine takes the incoming string and
replaces the \r with and \n with . Only the Unix version of the
directory listing function might use the platform specific line
termination constant so the string is really converted into
somethingsomething else..... and this is not treated as multi
line in most browsers.

> Navigating through the files and dirs shows only web related contents
> but none of my VIs. Clicking on "index.htm" brings the G Web Server
> welcome screen just as expected. I can navigate through the example
> pages, but every time I click on a VI example I only get unreadable
> gibberish, like as my browser reads the binary contents of the VI as
> ASCII characters. Same symptoms as discussed in Document ID: 0VJC8SSG
> but solution apparently not applicable.

This has to do with wrong Content-Type/Mime-Type in the HTTP header or a
broken browser client.

> A remote computer on Win32 or Linux behaves the same.
> I already have ITK and proper VI running on Win32 and it works fine,
> also viewing that VI with Linux remote machine. But hosting same VI on
> Linux G web server only shows scrambled ASCII characters.
> See attached Gexppi.png and Gproj2.png

Hmm, it could be that the function to read the mime.type file to assign
the proper mime type to file endings also stumbles over the line endings
in that file. After all the Internet Toolkit for LabVIEW 5 is very old
and there might have been some fixes in the mean time. I believe I have
looked at the version which came with LabVIEW 6.1 but not sure if those
problems are solved there as I haven't really tried it out nor on
Windows nor on Linux.

Rolf Kalbermatter
Rolf Kalbermatter  My Blog
DEMO, Electronic and Mechanical Support department, room 36.LB00.390
0 Kudos
Message 2 of 2
(2,309 Views)