bash: kill $$ not work?

Question

The command `kill $$` should kill current bash, but it seems that it doesn't work: ``` $ ps -p $$ PID TTY TIME CMD 18179 pts/4 00:00:00 bash $ kill $$ $ ps -p $$ PID TTY TIME CMD 18179 pts/4 00:00:00 bash ``` Why?

Accepted Answer

I'm not sure why one would like to `kill` the current shell. Nevertheless...

`kill PID` would send `SIGTERM` when no signal is specified. `bash` ignores `SIGTERM` and `SIGQUIT` in the absence of any traps.

You'll achieve the desired effect if you were to say

```
kill -9 $$
```

or

```
kill -SIGKILL $$
```

Quoting from the manual:

When Bash is interactive, in the absence of any traps, it ignores `SIGTERM` (so that ‘`kill 0`’ does not kill an interactive shell), and `SIGINT` is caught and handled (so that the wait builtin is interruptible). When Bash receives a `SIGINT`, it breaks out of any executing loops. In all cases, Bash ignores `SIGQUIT`.

bash: kill $$ not work?

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