+++ /dev/null
-Test programs
--------------
-
-Cygwin
- emacs
- vim
- mc (Midnight Commander)
- lynx
- links
- less
- more
- wget
-
-Capturing the console output
-----------------------------
-
-Initial idea:
-
-In the agent, keep track of the remote terminal state for N lines of
-(window+history). Also keep track of the terminal size. Regularly poll for
-changes to the console screen buffer, then use some number of edits to bring
-the remote terminal into sync with the console.
-
-This idea seems to have trouble when a Unix terminal is resized. When the
-server receives a resize notification, it can have a hard time figuring out
-what the terminal did. Race conditions might also be a problem.
-
-The behavior of the terminal can be tricky:
-
- - When the window is expanded by one line, does the terminal add a blank line
- to the bottom or move a line from the history into the top?
-
- - When the window is shrunk by one line, does the terminal delete the topmost
- or the bottommost line? Can it delete the line with the cursor?
-
-Some popular behaviors for expanding:
- - [all] If there are no history lines, then add a line at the bottom.
- - [konsole] Always add a line at the bottom.
- - [putty,xterm,rxvt] Pull in a history line from the top.
- - [g-t] I can't tell. It seems to add a blank line, until the program writes
- to stdout or until I click the scroll bar, then the output "snaps" back down,
- pulling lines out of the history. I thought I saw different behavior
- between Ubuntu 10.10 and 11.10, so maybe GNOME 3 changed something. Avoid
- using "bash" to test this behavior because "bash" apparently always writes
- the prompt after terminal resize.
-
-Some popular behaviors for shrinking:
- - [konsole,putty,xterm,rxvt] If the line at the bottom is blank, then delete
- it. Otherwise, move the topmost line into history.
- - [g-t] If the line at the bottom has not been touched, then delete it.
- Otherwise, move the topmost line into history.
-
-(TODO: I need to test my theories about the terminal behavior better still.
-It's interesting to see how g-t handles clear differently than every other
-terminal.)
-
-There is an ANSI escape sequence (DSR) that sends the current cursor location
-to the terminal's input. One idea I had was to use this code to figure out how
-the terminal had handled a resize. I currently think this idea won't work due
-to race conditions.
-
-Newer idea:
-
-Keep track of the last N lines that have been sent to the remote terminal.
-Poll for changes to console output. When the output changes, send just the
-changed content to the terminal. In particular:
- - Don't send a cursor position (CUP) code. Instead, if the line that's 3
- steps up from the latest line changes, send a relative cursor up (CUU)
- code. It's OK to send an absolute column number code (CHA).
- - At least in general, don't try to send complete screenshots of the current
- console window.
-
-The idea is that sending just the changes should have good behavior for streams
-of output, even when those streams modify the output (e.g. an archiver, or
-maybe a downloader/packager/wget). I need to think about whether this works
-for full-screen programs (e.g. emacs, less, lynx, the above list of programs).
-
-I noticed that console programs don't typically modify the window or buffer
-coordinates. edit.com is an exception.
-
-I tested the pager in native Python (more?), and I verified that ENTER and SPACE
-both paid no attention to the location of the console window within the screen
-buffer. This makes sense -- why would they care? The Cygwin less, on the other
-hand, does care. If I scroll the window up, then Cygwin less will write to a
-position within the window. I didn't really expect this behavior, but it
-doesn't seem to be a problem.
-
-Setting up a TestNetServer service
-----------------------------------
-
-First run the deploy.sh script to copy files into deploy. Make sure
-TestNetServer.exe will run in a bare environment (no MinGW or Qt in the path).
-
-Install the Windows Server 2003 Resource Kit. It will have two programs in it,
-instsrv and srvany.
-
-Run:
-
- InstSrv TestNetServer <path-to-srvany>\srvany.exe
-
-This creates a service named "TestNetServer" that uses the Microsoft service
-wrapper. To configure the new service to run TestNetServer, set a registry
-value:
-
- [HKLM\SYSTEM\CurrentControlSet\Services\TestNetServer\Parameters]
- Application=<full-path>\TestNetServer.exe
-
-Also see http://www.iopus.com/guides/srvany.htm.
-
-To remove the service, run:
-
- InstSrv TestNetServer REMOVE
-
-TODO
-----
-
-Agent: When resizing the console, consider whether to add lines to the top
-or bottom. I remember thinking the current behavior was wrong for some
-application, but I forgot which one.
-
-Make the font as small as possible. The console window dimensions are limited by
-the screen size, so making the font small reduces an unnecessary limitation on the
-PseudoConsole size. There's a documented Vista/Win7 API for this
-(SetCurrentConsoleFontEx), and apparently WinXP has an undocumented API
-(SetConsoleFont):
- http://blogs.microsoft.co.il/blogs/pavely/archive/2009/07/23/changing-console-fonts.aspx
-
-Make the agent work with DOS programs like edit and qbasic.
- - Detect that the terminal program has resized the window/buffer and enter a
- simple just-scrape-and-dont-resize mode. Track the client window size and
- send the intersection of the console and the agent's client.
- - I also need to generate keyboard scan codes.
- - Solve the NTVDM.EXE console shutdown problem, probably by ignoring NTVDM.EXE
- when it appears on the GetConsoleProcessList list.
-
-Rename the agent? Is the term "proxy" more accurate?
-
-Optimize the polling. e.g. Use a longer poll interval when the console is idle.
-Do a minimal poll that checks whether the sync marker or window has moved.
-
-Increase the console buffer size to ~9000 lines. Beware making it so big that
-reading the sync column exhausts the 32KB conhost<->agent heap.
-
-Reduce the memory overhead of the agent. The agent's m_bufferData array can
-be small (a few hundred lines?) relative to the console buffer size.
-
-Try to handle console background color better.
- Unix terminal emulators have a user-configurable foreground and background
-color, and for best results, the agent really needs to avoid changing the colors,
-especially the background color. It's undesirable/ugly to SSH into a machine
-and see the command prompt change the colors. It's especially ugly that the
-terminal retains its original colors and only drawn cells get the new colors.
-(e.g. Resizing the window to the right uses the local terminal colors rather
-than the remote colors.) It's especially ugly in gnome-terminal, which draws
-user-configurable black as black, but VT100 black as dark-gray.
- If there were a way to query the terminal emulator's colors, then I could
-match the console's colors to the terminal and everything would just work. As
-far as I know, that's not possible.
- I thought of a kludge that might work. Instead of translating console white
-and black to VT/100 white and black, I would translate them to "reset" and
-"invert". I'd translate other colors normally. This approach should produce
-ideal results for command-line work and tolerable results for full-screen
-programs without configuration. Configuring the agent for black-on-white or
-white-on-black would produce ideal results in all situations.
- This kludge only really applies to the SSH application. For a Win32 Konsole
-application, it should be easy to get the colors right all the time.
-
-Try using the screen reader API:
- - To eliminate polling.
- - To detect when a line wraps. When a line wraps, it'd be nice not to send a
- CRLF to the terminal emulator so copy-and-paste works better.
- - To detect hard tabs with Cygwin.
-
-Implement VT100/ANSI escape sequence recognition for input. Decide where this
-functionality belongs. PseudoConsole.dll? Disambiguating ESC from an escape
-sequence might be tricky. For the SSH server, I was thinking that when a small
-SSH payload ended with an ESC character, I could assume the character was really
-an ESC keypress, on the assumption that if it were an escape sequence, the
-payload would probably contain the whole sequence. I'm not sure this works,
-especially if there's a lot of other traffic multiplexed on the SSH socket.
-
-Support Unicode.
- - Some DOS programs draw using line/box characters. Can these characters be
- translated to the Unicode equivalents?
-
-Create automated tests.
-
-Experiment with the Terminator emulator, an emulator that doesn't wrap lines.
-How many columns does it report having? What column does it report the cursor
-in as it's writing past the right end of the window? Will Terminator be a
-problem if I implement line wrapping detection in the agent?
-
-BUG: After the unix-adapter/pconsole.exe program exits, the blinking cursor is
-replaced with a hidden cursor.
-
-Fix assert() in the agent. If it fails, the failure message needs to be
-reported somewhere. Pop up a dialog box? Maybe switch the active desktop,
-then show a dialog box?
-
-TODO: There's already a pconsole project on GitHub. Maybe rename this project
-to something else? winpty?
-
-TODO: Can the DebugServer system be replaced with OutputDebugString? How
-do we decide whose processes' output to collect?
-
-TODO: Three executables:
- build/winpty-agent.exe
- build/winpty.dll
- build/console.exe
-
-BUG: Run the pconsole.exe inside another console. As I type dir, I see this:
- D:\rprichard\pconsole>
- D:\rprichard\pconsole>d
- D:\rprichard\pconsole>di
- D:\rprichard\pconsole>dir
- In the output of "dir", every other line is blank.
- There was a bug in Terminal::sendLine that was causing this to happen
- frequently. Now that I fixed it, this bug should only manifest on lines
- whose last column is not a space (i.e. a full line).
projects / VSoRC / .git / blobdiff