Managing subprocesses

[The-Compiler]

It'd nice if qutebrowser had a way to manage its subprocesses:

• Anything started via :spawn
• Userscripts currently running
• Open editors
• Per-tab QtWebEngine suprocesses (since Qt 5.15)

This could probably work via commands and the completion. Possibly useful commands:

• :process-kill
• :process-list listing all processes on a HTML page (though the completion for :process-kill might be enough already?)
• :process-show-pid (see above)
• :process-detach for detaching :spawn processes after spawning them, so that qutebrowser can be quit. Though that might not be possible with Qt: [QTBUG-9328] Add support for detaching from a started process (like QProcess::detach()) - Qt Bug Tracker. Not sure why, given that disown in a shell exists.
• :process-clear to clear the process list, see [Feature request] datetime in process list and details #6716

[emanuele6]

Thank you!

[LiteracyFanatic]

I think this would be really useful, especially having access to the rendering subprocesses. In addition to listing the info on an HTML page, I would want a way to get a hold of the the PIDs and associated metadata (page title, URL, etc.) in an easily parsable format from a shell script. My main use case would be memory monitoring and integration with nohang. qutebrowser is usually the victim when it needs to kill something to prevent a hang, but it'd be nice to have the information necessary to prevent killing certain important tabs.

[The-Compiler]

I just pushed a first version of a :process command. It doesn't handle QtWebEngine processes yet though, only things spawned by qutebrowser itself (such as :spawn, or external editors).

[ghost]

edit: problem 1 (progress bar) solved by calling wget with --progress=bar:force

Hello. I started to use :spawn with ranger/dmenu (to find dirs and create new file names) and wget as a replacement of the default download functions qutebrowser provides. I'm also using :spawn (with ranger/youtube-dl) to download youtube videos and do some other tasks (things like curl+some post process). All this works fine except for the output messages wich (unless I'm missing something) qutebrowser doesn't handle very well (It keeps stacking download progress messages, which can be turned off but that gives no feedback at all). Also I have to use config.bind(',k', 'spawn pkill wget') to cancel downloads which is not that great. There is any hope qutebrowser could better support progress messages and process killing? If not I think I could try to search/write an external download manager, a generic process manager more or less.

Thanks a lot, here is my script replacing the download functions. More here

config.bind(',d', 'hint links spawn -u   download-file {hint-url}')
config.bind(',D', 'spawn -u  download-file {url}')

#!/usr/bin/env sh
prev_path=$(head -n 1 ~/.qutebrowser_tmp_path)
filename=$(echo $1 | sed -n 's/.*\///p')
truncate -s 0 ~/.qutebrowser_tmp_path
xterm -e ranger $prev_path --show-only-dirs --choosedir ~/.qutebrowser_tmp_path
path=$(head -n 1 ~/.qutebrowser_tmp_path)
if [ "$path" != "" ]; then
   name="$(echo -e $filename | dmenu)"
   wget "$1" -O "$path/$name" -nv --show-progress --progress=bar:force 2>&1 && echo "Download completed"
else
   echo "Download canceled"
fi

[toofar]

There is the :process command for doing some things with spawned processes, haven't used it in anger myself https://qutebrowser.org/doc/help/commands.html#process
I'm not aware of if anyone has done anything particularly generic around managing processes from userscripts or whatever. If you end up making a download manager then there is probably stuff better to build around than wget (like aria2 which apparently has RPC already).

[ghost]

Thank you, Aria2 looks very great. Having solved the progress bar problem, I think the baby functions I wrote are already doing a decent job. A dedicated, multi protocol, standalone download/process manager still sounds cool. I mean, something like a daemon serving one http interface showing all progress bars, process-kill buttons and what not. Another vim-like CLI interface could be also nice. But I don't know, it's a lot of work for something already working decently enough with some basic tools and very little of code. Maybe I'll get into It although The-Compiler also mentioned something similar to be done in qutebrowser, If I'm not mistaken.

:process-list listing all processes on a HTML page

Also you where right, I didn't knew the :process command already can take pids and actions. I'll try to use that somehow. Thanks.