Get pid of current subshell

Question

I am trying to get the pid of a currently executing subshell - but $$ is only returning the parent pid:

#!/usr/bin/sh

x() {
  echo \"I am a sub         


        

Answer 1

@John1024 's answer is great, but there's a little problem in there.

when a command run like (...), the command will run in a new subprocess, so

( : ; bash -c 'echo $PPID' ) 

will return process_id of (...)， not the function's process id that call (...)

if you want the function's process_id, you can just run:

$SHELL -c 'echo $PPID'

and the process_id will be outputed to stderr

if you want get the function's process_id form a variable, you can run:

$SHELL -c 'echo $PPID' | read -s func_pid

then you can get the pid from variable ${func_pid}

note: don't run this command in (...), otherwise it'll return the process_id of (...)