cd(1posix) /var/mail && ping(8)
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.
AND and OR lists are sequences of one of more pipelines separated by the &&  and  ||  control  operators,
respectively.  AND and OR lists are executed with left associativity.  An AND list has the form

       command1 && command2

command2 is executed if, and only if, command1 returns an exit status of zero.

An OR list has the form

       command1 || command2

command2  is  executed  if and only if command1 returns a non-zero exit status.  The return status of AND
and OR lists is the exit status of the last command executed in the list.
send ICMP ECHO_REQUEST packets to network hosts
ping [-Rdfnqrv] [-c count] [-i wait] [-l preload] [-p pattern] [-s packetsize] host
source manpages: cdping