If nobody complains about it in another week, I'll package it up as a new Leo command.
On Monday, February 6, 2023 at 4:15:40 AM UTC-5 jkn wrote: > 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/3c2b205c-26cf-4253-9ae2-9e9d29427db9n%40googlegroups.com.
