[BRLTTY] link to screen source

[Cheryl Homiak]

Hi John.

I was going to post this privately but I am also posting to the list because I thought it might be helpful for others to see the modifications I have made to the text file with the screen instructions. For one thing, the link in those instructions for screen no longer appears to be a working link. Also, I have tailored the instructions specifically for the Mac. The original instructions for compiling and installing screen are actually in a text file in the Patches section of the brltty source. If you are installing to a directory where you are not needing sudo , you can ignore the inclusion of sudo.

I am including the link for screen-4.2.1 in the appropriate place in the instructions.  This is not the newest version of screen and it is not the one that is the port in macports but it is the latest one that I know there is a specific patch for applying. I actually still usually use screen-4.0.1 but I have used both and 4.2.1 is later and I think that 4.0.1 may not even be available any more online though I am not sure. First I would recommend that you delete the version of screen you already installed for use with brltty. It is possible that the patch may work with later versions but I would rather be cautious and give you what I know should work.

It is fine to have brltty and screen in /opt/local; just remember that they are not actually Macports ports so if for some reason you uninstall your Macports (which is usually recommended when you upgrade to a new full installation (like going from sierra to high sierra) that screen and brltty will not be ports to reinstall but will have to be obtained again. I am assuming you used git to download brltty; if you obtained it in some other way please explain. I also am assuming that your compilation and installation of brltty went without any errors. The instructions for installing brltty are included in the text file, which I have actually just pasted as text in this email, but of course if brltty is already installed you won't need to redo that.

Don't hesitate to email me directly or onlist if you have problems or questions. I'm sorry this has turned out to be frustrating.


Running brltty with screen on Mac
Introduction
============

Shared memory is another method for BRLTTY to get the content of the screen.
For this method you need two components:

*  Some other application needs to maintain the shared screen image. This can 
   be done via the screen program when augmented by a BRLTTY-supplied patch.
*  BRLTTY needs to be able to view the shared screen image. This is done via
   its Screen screen driver.

The original purpose of screen was to run different "screens" on a single
terminal. It also supports features like copy-and-paste, a scrollback buffer,
etc. Screen supports lots of terminal types, especially XTERM. This is
important because it runs under X-Windows which is part of most unixes.

Instructions
============

1) Build and install BRLTTY:

If you are using the git repository go to whatever directory you like to keep source in and do:

sudo git clone https://github.com/brltty/brltty.git

sudo ./autogen

Then, whether you have used git or have downloaded and unpacked source for a specific version, , do:

sudo ./cfg-darwin

      sudo make
      sudo make install
   
   BRLTTY's Screen screen driver will be built by default.
Be sure not to 
   explicitly exclude it via, for example, a configure option like:

      --with-screen-driver=-sc

(In other words, just run sudo ./darwin-cfg --prefix=/opt/local)

2) Get the source for screen:
Since this is ftp which if approached directly will behave somewhat differently in safari  though it actually will work by having you open the ftp site in finder,, I am instead giving you the main link from which you will click the link to the actual index and can then select the version. This allows you to do the whole process in safari and the file will download.

https://www.gnu.org/software/screen/

3) Unpack the source unless it unpacks automatically when downloaded:

 sudo tar xzf /path/to/screen-4.0.1.tar.gz

4) Change to the source tree:

      cd path/to/screen-4.2.1 

5) Apply the patch: 

      sudo patch -p0 </path/to/brltty/Patches/screen-4.2.1.patch
(Note the less-than sign.)

Brltty here is the location of your source from which you compiled.

6) Build screen:

      sudo ./configure
      sudo make
      sudo make install


While it may not be necessary, I usually also do the follwing:

sudo chmod u-s (path to screen)
sudo ln -s (path to screen) (path to symlink)
Example:
sudo ln -s /opt/local/bin/screen-4.2.1 /opt/local/bin/screen

running screen and brltty
1. Start screen from terminal.
2. Make sure you are at the shell prompt.
3. Start brltty either with command-line options or just the brltty command itself if you have a brltty.conf set up. I usually type brltty and then turn voiceover off and then press enter.

   The only order dependency is that screen must be run first the first time in
   order to get the shared memory segment created. Although brltty can be run
   first from then on, the shared memory image will, of course, be stale until
   screen is started. Often if terminal is quit or crashes, when you start terminal again and open screen, brltty will come back up without being started again. If you want to make sure brltty completely quits, do:
killall -9 brltty

Screen and brltty both run on the Mac for you as a user and do not need to be run with sudo or by root.


BRLTTY's screen patch was originally developed by Rudolf Weeber
<rudolf.weeber at gmx.de>.


  
-- 
Cheryl

May the words of my mouth
and the meditation of my heart
be acceptable to You, Lord,
my rock and my Redeemer.
(Psalm 19:14 HCSB)