/proc/pid/cwd − symbolic link to current working directory
/proc/pid/cwd
This is a symbolic link to the current working directory of the process. To find out the current working directory of process 20, for instance, you can do this:
$ cd /proc/20/cwd; pwd −P
In a multithreaded process, the contents of this symbolic link are not available if the main thread has already terminated (typically by calling pthread_exit(3)).
Permission to dereference or read (readlink(2)) this symbolic link is governed by a ptrace access mode PTRACE_MODE_READ_FSCREDS check; see ptrace(2).
proc(5)