Re: Ctrl+4 means SIGQUIT+coredump, where is this documented, what more shortcuts are there?

On 2018-10-31, Tinker <t1nkr@protonmail.ch> wrote:
> Hi,
>
> When in "cat" or "dd if=/dev/zero of=/dev/zero" or "gzip < /dev/zero >
> /dev/zero", if I press ctrl+4, the program coredumps.
>
> Doing it in ksh or sh has no effect though.
>
> This is in OpenBSD 6.4 AMD64 from Putty on Windows.
>
> The console interaction looks like this:
>
> $ cat
> ^\Quit (core dumped)
>
> $
>
>
> Is ctrl+4 a universal SIGQUIT+coredump shortcut?
>
> Where are the other shortcuts apart from ctrl+C, ctrl+Z, ctrl+D,
> documented?
>
> Tinker
>
>

No idea how ^4 is mapped to ^\, but for some reason it is, and this
the default for "quit", see "stty -a".

This is a useful sequence to interrupt boot if you weren't quick enough
to "boot -s" to enter single-user mode.