cd(1posix) $(dirname $0); pwd(1)
change the working directory
       An absolute or relative pathname of the directory that shall become the new working directory. The
       interpretation of a relative pathname by cd depends on the  -L  option  and  the  CDPATH  and  PWD
       environment variables. If directory is an empty string, the results are unspecified.

-      When a hyphen is used as the operand, this shall be equivalent to the command:

       cd "$OLDPWD" && pwd

which changes to the previous working directory and then writes its name.
Commands separated  by  a ; are executed sequentially; the shell waits for each command to terminate in turn.  The
return status is the exit status of the last command executed.
print name of current/working directory
source manpages: cdpwd