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

If you use Linux-kernel, you can use Linux-kernel's /proc/self feature to do this:

In simplest form: cd -P /proc/self && basename "${PWD}"

To keep the PWD and OLDPWD variable: PWD_BACKUP="${PWD}";OLDPWD_BACKUP="${OLDPWD}";cd -P /proc/self && basename "${PWD}";cd "${PWD_BACKUP}";OLDPWD="${OLDPWD_BACKUP}"

For example:

$ cd -P /proc/self && basename "${PWD}"
26758
$ (cd -P /proc/self && basename "${PWD}")
26959
$ (cd -P /proc/self && basename "${PWD}")
26961
$