How to close other shells except current?

This is actually not as easy as it might seem at first. The main challenge is that the ps utility is rather incompatible between different platforms, which creates a very significant risk that assumptions you make about ps won't always be correct on systems where you might use the script. And since the task is a rather... dangerous one, you would want to be careful here. Just as an example, the ps on my current system (Cygwin) does not have a -o option, while yours appears to have one.

Anyway, here's my solution:

pidCol=$(ps| head -1| awk '{ for (i = 1; i <= NF; ++i) if ($i == "PID") { print(i); exit; }; };');if [[ -n "$pidCol" ]]; then    ps| tail -n+2| grep sh$| cut -c2-| awk "{ print(\$$pidCol); };"| grep -v "^$$\$"| xargs kill -9;fi;

It first gets the column number in ps's output that contains the PID of the process. I tried to make it as robust as possible by parsing the ps header line. So if the PID column position varies between systems, we should still get it correctly for the current system.

Then, I've applied a guard around the kill pipeline to ensure it only runs if we successfully got the $pidCol from the parse command.

Then, in the actual kill pipeline, I strip off the header, grep for all sh processes, cut off the first character (because ps on some systems prints a little character indicator at the beginning of some (but not all) lines that does not get a corresponding column name in the header line), and then use awk to just print the PID column value. Finally, I grep out the current process's PID and run the remaining PIDs through xargs kill -9.

You can make use of $$ here in this ps piped with awk:

ps -o pid,tty,comm | awk -v curr=$$ '$3 ~ /sh/ && $1 != curr'

The variable $$ represents the PID of current shell.

You can get your current shell with tty and "clean" it to get the data after the 2nd slash like this:

current=$(tty | cut -d/ -f3-)

Then, it is a matter of printing all the results in ps -o pid,tty,comm whose second column does not match your current one... and leaving the header out:

ps -o pid,tty,comm | awk -v current="$current" 'NR>1 && $2!=current {print $1}'

Then, you can loop through this result and kill the given PIDs.