--help display this help and exit

--version
       output version information and exit

Print  the  value  of  EXPRESSION to standard output.  A blank line below separates increasing precedence
groups.  EXPRESSION may be:

ARG1 | ARG2
       ARG1 if it is neither null nor 0, otherwise ARG2

ARG1 & ARG2
       ARG1 if neither argument is null or 0, otherwise 0

ARG1 < ARG2
       ARG1 is less than ARG2

ARG1 = ARG2
       ARG1 is equal to ARG2