I'll give it a try (kubuntu linux, mainly) and let you know what I find... On Monday, February 6, 2023 at 6:18:42 AM UTC tbp1...@gmail.com wrote:
> I've been working on a command to run an external file (@file, @clean > ...). I think it is ready, and I'd appreciate it if other folks could test > it for me. The idea is that you select a node in the external file tree > and launch the command. It works on Windows and Linux but not Mac (I need > more information about the Mac, and I don't have one for testing). > > As long as the processing program such as Ruby, Python, Julia, is on the > path (and the file is a known file type) - or you specify it in a @data > setting node - a new terminal will open, run your GUI or console program, > and wait for you to close it. > > The new command is the @button node in the attached Leo outline. I > suggest copying in into the @buttons tree in your myLeoSettings.leo outline > and restarting Leo. > > The languages it can handle without adding an @data node - it's documented > in the command's docstring - are python, shell, batch (for Windows), ruby, > lua, and julia. > > Here are some technical details - > > This command was hard to get working right on Linux (and I can't swear > that it will work on Linux if the external file name has spaces), and the > reason was my requirement to open a new terminal and keep it open after the > external program finishes. I want that so that any output can be seen and > studied. > > It's easy to launch a program and have it write to Leo's own console, but > that is not ideal, because 1) other Leo output may get mixed in with the > external program's or the output may get scrolled offscreen; 2) if the > external program crashes, it may leave your Leo console running a secondary > shell; and 3) if you launch a GUI program that lasts a long time your > output may get very confusing. > > It turns out that to reliably keep the new terminal open on Linux, you > have to open a terminal and use that to run the shell, not just launch the > shell. This is a problem because there are a lot of Linux distros and they > don't all have the same terminal. In particular, the different terminals > don't always use the same options to run a shell with its command line. > The shell may also differ. Almost all desktops use bash, usually at > /usr/bin/bash, but a user can change that and some do. > > So we can't assume that the shell will be bash, nor what the terminal may > be. x-terminal-emulator does not give you the same options across distros, > either. $TERM doesn't actually give you the terminal either, just a > logical terminal so the right colors can be set up. > > To keep the terminal open after the command runs, some terminals have an > option for that, some have the option but it doesn't work, and some don't > have the option. Also, the option name is subject to change (I found at > least one distro that issued a deprecation warning) So we need another > solution. My solution is to have the shell wait for user input after the > main command finishes. After a long time running queries on the Internet I > have not found a more workable way. > > So how do we find the terminal and shell? By running pstree -s $$ and > parsing its output. Then we run that terminal with --help and try to > parse the help message to find the right option. This works on all cases > I've tried, but it's probably a little fragile. > > If the shell isn't bash, or we can't figure it out, we use the $SHELL > variable. > > Then we use the command's internal table, or the system file association, > to find the right processor to run. We also check to make sure it can > actually be found. > > Finally we can construct the command and run it. Whew, that was tricky! > It's easier on Windows because we don't have to discover the terminal and > shell, and the launch options are always the same. > > For the Mac, I don't know the terminal or shell names nor the right > options to invoke. I'm pretty sure that if I learn them this command will > work on a Mac too. > > -- You received this message because you are subscribed to the Google Groups "leo-editor" group. To unsubscribe from this group and stop receiving emails from it, send an email to leo-editor+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/leo-editor/c8d458db-c01c-4c61-aa80-ed49ecf282a9n%40googlegroups.com.
