Making the Firefox / Chromium choice in sdm?

[tinker2much]

What about adding into sdm the equivalent of the choice in the stock wizard that asks which of the two browsers you want as the default or whether you want either of them deleted?

This may currently be (partly) implemented using the standard Debian alternatives system.

[gitbls]

How is this different than using the apps plugin to install or remove one or other of the browsers?

That said, I agree that there might be a use for a plugin to manage the update-alternatives settings once the correct browser is installed.

Thoughts?

[tinker2much]

Just thinking about those customizations I still do myself, post sdm.
I agree that the apps plugin could add or delete browsers.
But if you wanted to leave both Firefox and Chromium installed, just change the default to Firefox, that would be nice to have sdm handle too. And update-alternatives commands would probably be the way to do it.

[gitbls]

I was thinking that the plugin would do 2 functions:

• list - do an update-alternative --get-selections which would go to the console and history
• set - "set=NAME|path=/path/to/prog" would set selection NAME to the specified path

Primitive, but elegant 😉 Thoughts?

[tinker2much]

FYI: The only operations I ever do with the alternatives system are install, remove, and config:

add a new program as an alternative:
sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /usr/bin/netsurf 40
sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /home/pi/bin/chromium-flatpak 95

remove a program as an alternative:
sudo update-alternatives --remove x-www-browser /home/pi/bin/chromium-browser

interactively choose an alternative (only when needing to pick one with a lower priority, otherwise the highest priority one is used)
sudo update-alternatives --config x-www-browser

( I haven't gone to the man pages to see if there's a non-interactive way to do the last operation. )

[tinker2much]

I wonder how raspi-config sets it?

[1stcall]

@tinker2much
update-alternatives --set x-www-browser /usr/bin/$BROWSER > /dev/null
sudo -u $USER xdg-settings set default-web-browser $BROWSER.desktop

[tinker2much]

Just found the browser setting stuff myself, in routines do_browser and get_browser in raspi-config here.
I always have trouble finding RPI sources, even with their seemingly helpful sources page here. Thank heavens for search engines.

[tinker2much]

If you also had an option to ADD a new executable, that would cover my real needs.
I don’t really need a remove function, since I can just leave the undesired ones in the list and ignore them.

[gitbls]

If you also had an option to ADD a new executable, that would cover my real needs. I don’t really need a remove function, since I can just leave the undesired ones in the list and ignore them.

To clarify, do you mean to add a new name or to add a new alternative to an existing name? IOW:

• Add x-myname (add a new name) and optionally set a value for it
• Add /usr/bin/brave as a new executable for x-www-browser (which already exists)

[tinker2much]

I meant adding a new executable for an existing name.

[gitbls]

I meant adding a new executable for an existing name.

Perfect. That will be there. I just need a fresh burst of new-plugin energy 😐

[gitbls]

Separately, just to note that plugin runatboot can be used to run a script that does the update-alternatives, but seems that a separate plugin to do this would be less muss/fuss

[tinker2much]

I think a specific feature is simpler. Also, design wise, I think there's a lot of value in sdm being able to set many/most of the things that a standard rpi wizard or rasp-config can do.

That's what I thought when I saw them starting to ask the Firefox/Chromium questions.

[gitbls]

I think this fits the bill? Comments appreciated!

update-alternatives

Use the update-alternatives plugin to manipulate the Debian alternatives system.

Arguments

• get-selections — Output the current alternatives list to the console and /etc/sdm/history
• set-many — Set a series of alternatives. See below
• set-one — Set one alternative. set-one provides the name to set (e.g., editor) and path provides the value
• path — The path to a registered alternative for selection set-one

Examples

• --plugin update-alternatives:get-selections — Print the list of selections to the console and the log
• --plugin update-alternatives:"set-one=x-terminal-emulator|path=/usr/bin/xterm" — Set the selection x-terminal-emulator to alternative /usr/bin/xterm
• --plugin update-alternatives:set-many=/path/to/list — Set many alternatives at once.

Example series of alternatives for set-many

Each line in the file for set-many consists of three fields: selection-name manual /path/to/alternative
The specified alternative must already be registered in the Debian alternatives system, typically when the package is installed

editor manual /bin/ed
pager manual /bin/more

[tinker2much]

Those options take care of several use cases:

1. getting the list of the current alternatives, and
2. choosing one of the current alternatives

But what about where you want to add a new alternative and therefore also have to specify a priority? Like these commands - remember "install" means you're installing the alternative,, not the program. The program is assumed to already exist on the system.

add a new program as an alternative:
sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /usr/bin/netsurf 40
sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /home/pi/bin/chromium-flatpak 95

What does the word "manual" do in your implementation?

[gitbls]

Great questions! Indeed, hadn't gotten to --install, wanted to see if there was use for it. Apparently there is!

The word "manual" is what YOU would add to your "set-many" file. sdm just passes the file to update-alternatives.

My reco to use "manual" was based on experimentation with the --set-selections command. Only manual worked as expected. I probably missed something, so feel free to enlighten me!

[gitbls]

Updated doc for feedback. Thx!

update-alternatives

• get-selections — Output the current alternatives list to the console and /etc/sdm/history
• install-alternative — Install an alternative in the system. Requires link, path, and priority arguments. See Examples
• link — The generic name for the master link (e.g., /usr/bin/something)
• priority — Sets the priority for the alternative. When a link group is in automatic mode, the alternatives pointed to will be those which have the highest priority.
• set-many — Set a series of alternatives. See below
• set-one — Set one alternative. set-one provides the name to set (e.g., editor) and path provides the value
• path — The path to a registered alternative for selection set-one

Examples

• --plugin update-alternatives:get-selections — Print the list of selections to the console and the log
• --plugin update-alternatives:"set-one=x-terminal-emulator|path=/usr/bin/xterm" — Set the selection x-terminal-emulator to alternative /usr/bin/xterm
• --plugin update-alternatives:"set-many=/path/to/list" — Set many alternatives at once.
• --plugin update-alternatives:"install-alternative=vedit/usr/bin/vedit|link=vedit|path=/usr/bin/vedit|priority=40" Install a new alternative

[tinker2much]

I’m confused by “install-alternative=vedit/usr/bin/vedit” - is that an extra vedit up front?

[tinker2much]

Could you please put all of my examples above into your proposed sdm update-alternatives formats? That would make things clear to me.

[gitbls]

I’m confused by “install-alternative=vedit/usr/bin/vedit” - is that an extra vedit up front?

Yea, me too. Looks like an editing snafu. Your

sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /usr/bin/netsurf 40

would be

--plugin update-alternatives:"install-alternative=x-www-browser|link=/usr/bin/x-www-browser|path=/usr/bin/netsurf|priority=40"

[tinker2much]

It all looks fine to me.

[gitbls]

Thx for your suggestions and taking a look at it!

[tinker2much]

I’ll test as soon as this is in git.

[gitbls]

I’ll test as soon as this is in git.

Excellent. It's there in V14.5. Note that a couple of the arg names changed to eliminate doc confusion.

Looking forward to your feedback.

[tinker2much]

I tried the following, and they all worked great!

--plugin update-alternatives:"install-alternative=x-www-browser|link=/usr/bin/x-www-browser|installpath=/home/pi/bin/chromium-flatpak|priority=40" \
--plugin update-alternatives:"set-one=x-www-browser|setpath=/home/pi/bin/chromium-flatpak" \
--plugin update-alternatives:get-selections \

I was surprised to see get-selections return the CURRENTLY selected choice for ALL alternatives, because I had it in my head that it would be returning ALL the possibilities for some PARTICULAR alternative. But that's just my brain thinking what it wants to.

Perhaps this could be an optional parameter to get-selections which would specify the particular alternatives to go deeper on - like someoption="editor|x-www-browser" would give add a more detailed report on just those two alternatives, actually showing ALL the choices, with the data (through not the format) being like this:

Name:  editor
Value:  /bin/nano
 40  /bin/nano
 25  /usr/bin/mcedit
 15  /usr/bin/vim.tiny
 -100  /bin/ed

Name:  x-www-browser
Value:  /home/pi/bin/chromium-flatpak
 90  /usr/bin/chromium
 70  /usr/bin/firefox
 40  /home/pi/bin/chromium-flatpak

That would be useful in a case like mine, where I both added the chromium-flatpack alternative and set it, but would like to see the whole picture of how my choice fits among the other possibilities.

FYI: my script to produce the report above is the following, falling back on awk because I'm not the bash guy you are:

xyz@MacBook-Air bin % cat alts
#!/usr/bin/bash

sudo update-alternatives --query $1 | awk '
BEGIN { FS=":" }
/Name:|Best:|Value:|Alternative:|Priority:/ {
	val[$1] = $2
	}
/Name:|Value:/ {
	print $1 ":", val[$1]
	}
/Priority:/ {
	print val["Priority"], val["Alternative"] | "sort -k1,1nr"
	}'

[tinker2much]

If you just pass through the query call, which might be a good thing (what you're doing with the others) you get the following, which isn't as pretty, but even more informative. ;-)

Name: x-www-browser
Link: /usr/bin/x-www-browser
Slaves:
x-www-browser.1.gz /usr/share/man/man1/x-www-browser.1.gz
Status: manual
Best: /usr/bin/chromium
Value: /home/pi/bin/chromium-flatpak

Alternative: /home/pi/bin/chromium-flatpak
Priority: 40
Slaves:

Alternative: /usr/bin/chromium
Priority: 90
Slaves:

Alternative: /usr/bin/firefox
Priority: 70
Slaves:
x-www-browser.1.gz /usr/share/man/man1/firefox.1.gz

[gitbls]

This should do it? A query argument that takes a comma-separated list of things to query:

--plugin update-alternatives:"query=x-www-browser,which"

would run update-alternatives --query on each provided element.

And could also do query-short argument that provides --config-like output:

--plugin update-alternatives:"query-short=x-terminal-emulator"  #Could also be a comma-separated list of course

Output:

There are 4 choices for the alternative x-terminal-emulator (providing /usr/bin/x-terminal-emulator).

  Selection    Path                 Priority   Status
------------------------------------------------------------
  0            /usr/bin/lxterm       30        auto mode
  1            /usr/bin/koi8rxterm   20        manual mode
  2            /usr/bin/lxterm       30        manual mode
  3            /usr/bin/uxterm       20        manual mode
* 4            /usr/bin/xterm        20        manual mode

Press <enter> to keep the current choice[*], or type selection number: 

If I ignore the possibility of translated update-alternatives output, can also filter out the "Presss " line.

Seems to me that query-short would be generally more useful and easier to digest...thoughts?

[tinker2much]

the proposed straight query syntax would be fine for the data-hungry. I agree that the query-short option would be most generally useful - that's what I would use.

can you just redirect a newline into the config call?

[gitbls]

pw/etc/systemd/system# update-alternatives --config x-terminal-emulator < /dev/null
There are 4 choices for the alternative x-terminal-emulator (providing /usr/bin/x-terminal-emulator).

  Selection    Path                 Priority   Status
------------------------------------------------------------
  0            /usr/bin/lxterm       30        auto mode
  1            /usr/bin/koi8rxterm   20        manual mode
  2            /usr/bin/lxterm       30        manual mode
  3            /usr/bin/uxterm       20        manual mode
* 4            /usr/bin/xterm        20        manual mode

Press <enter> to keep the current choice[*], or type selection number: pw/etc/systemd/system# 
pw/etc/systemd/system# 

I will get rid of the line (or maybe any line with '<' in it in hopes that translations will mimic that)

[gitbls]

I've updated plugins/update-alternatives and sdm-cparse. Copy them from github to your system in the appropriate places. Also Docs/Plugins.md is updated for argument query-selection. But I think maybe this should be query-alternative? What do you think?

ps Guess I'm going to have to learn more about github branches 😲

[tinker2much]

query-alternative sounds better

[gitbls]

Agree and updated.