On Ubuntu 20.04, I start Emacs by `emacs -Q', and then hit `C-M-s' (Ctrl + Alt + s), which by default will trigger the `isearch-forward-regexp' function, but I see nothing happened.

So, I want to pinpoint the tool/utility which occupies a specific system shortcut key, in this case, `C-M-s' (Ctrl + Alt + s). Any hints will be highly appreciated.

Regards,
HY

--- SoupGate-Win32 v1.05
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"[email protected]" <[email protected]> writes:

On Ubuntu 20.04, I start Emacs by `emacs -Q', and then hit `C-M-s'
(Ctrl + Alt + s), which by default will trigger the
`isearch-forward-regexp' function, but I see nothing happened.

Quite a lot of Ctrl+Alt keys are bound by the Gnome shell. If that
happens, you won't see emacs doing anything. And if the Gnome action is silent, the result is very puzzling at first.

Go to your preferences and select Keyboard Shortcuts. You can search
for "Ctrl+Alt+s" (you type that as text: C, t, r, l, + and so on, not
the single keystroke "chord"). On my system it's bound to "mark the
active item as being a password".

So, I want to pinpoint the tool/utility which occupies a specific
system shortcut key, in this case, `C-M-s' (Ctrl + Alt + s). Any hints
will be highly appreciated.

If the keystroke gets through to emacs, you can use describe-key which
should be bound to C-h k.

--
Ben.

--- SoupGate-Win32 v1.05
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On Sunday, August 1, 2021 at 9:22:27 PM UTC+8, [email protected] wrote:

On Sunday, August 1, 2021 at 5:26:04 PM UTC+8, Ben Bacarisse wrote:

"[email protected]" <[email protected]> writes:

On Ubuntu 20.04, I start Emacs by `emacs -Q', and then hit `C-M-s'
(Ctrl + Alt + s), which by default will trigger the `isearch-forward-regexp' function, but I see nothing happened.

Quite a lot of Ctrl+Alt keys are bound by the Gnome shell. If that
happens, you won't see emacs doing anything. And if the Gnome action is silent, the result is very puzzling at first.

Go to your preferences and select Keyboard Shortcuts. You can search
for "Ctrl+Alt+s" (you type that as text: C, t, r, l, + and so on, not
the single keystroke "chord"). On my system it's bound to "mark the
active item as being a password".

But I can't find the search butter at all on that panel. So I try to uncheck the `Enable shortcuts' option, and find that it does the trick.

I also tried with gsettings, but still can't find the keybinding for "Ctrl+Alt+s":

$ gsettings list-schemas | xargs -n1 gsettings list-recursively |grep -iF '<Control><Alt>'
org.gnome.settings-daemon.plugins.media-keys logout ['<Control><Alt>Delete'] org.gnome.desktop.wm.keybindings cycle-panels ['<Control><Alt>Escape'] org.gnome.desktop.wm.keybindings switch-panels ['<Control><Alt>Tab'] org.gnome.desktop.wm.keybindings switch-panels-backward ['<Shift><Control><Alt>Tab']
org.gnome.desktop.wm.keybindings switch-to-workspace-up ['<Super>Page_Up', '<Control><Alt>Up']
org.gnome.desktop.wm.keybindings switch-to-workspace-left ['<Control><Alt>Left']
org.gnome.desktop.wm.keybindings switch-to-workspace-right ['<Control><Alt>Right']
org.gnome.desktop.wm.keybindings switch-to-workspace-down ['<Super>Page_Down', '<Control><Alt>Down']
org.gnome.desktop.wm.keybindings cycle-panels-backward ['<Shift><Control><Alt>Escape']
org.gnome.settings-daemon.plugins.media-keys logout ['<Control><Alt>Delete']

So, I want to pinpoint the tool/utility which occupies a specific
system shortcut key, in this case, `C-M-s' (Ctrl + Alt + s). Any hints will be highly appreciated.

If the keystroke gets through to emacs, you can use describe-key which should be bound to C-h k.

Yes. By unchecking the `Enable shortcuts' option on GNOME Terminal's shortcuts panel, I can confirm `C-h k C-M-s RET' says the following:

C-M-s runs the command isearch-forward-regexp

Regards,
HY

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Sunday, August 1, 2021 at 5:26:04 PM UTC+8, Ben Bacarisse wrote:

"[email protected]" <[email protected]> writes:

On Ubuntu 20.04, I start Emacs by `emacs -Q', and then hit `C-M-s'
(Ctrl + Alt + s), which by default will trigger the `isearch-forward-regexp' function, but I see nothing happened.

Quite a lot of Ctrl+Alt keys are bound by the Gnome shell. If that
happens, you won't see emacs doing anything. And if the Gnome action is silent, the result is very puzzling at first.

Go to your preferences and select Keyboard Shortcuts. You can search
for "Ctrl+Alt+s" (you type that as text: C, t, r, l, + and so on, not
the single keystroke "chord"). On my system it's bound to "mark the
active item as being a password".

But I can't find the search butter at all on that panel. So I try to uncheck the `Enable shortcuts' option, and find that it does the trick.

So, I want to pinpoint the tool/utility which occupies a specific
system shortcut key, in this case, `C-M-s' (Ctrl + Alt + s). Any hints
will be highly appreciated.

If the keystroke gets through to emacs, you can use describe-key which
should be bound to C-h k.

Yes. By unchecking the `Enable shortcuts' option on GNOME Terminal's shortcuts panel, I can confirm `C-h k C-M-s RET' says the following:

C-M-s runs the command isearch-forward-regexp

Regards,
HY

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)