alias [ {+|-}gmrL ] [ name[=value] ... ]
       For each name with a corresponding value, define an
       alias  with  that value.  A trailing space in value
       causes the  next  word  to  be  checked  for  alias
       expansion.   If  the  -g  flag is present, define a
       global alias; global aliases are expanded  even  if
       they do not occur in command position.

       For  each  name  with  no value, print the value of
       name,  if  any.   With  no  arguments,  print   all
       currently defined aliases.  If the -m flag is given
       the arguments are taken as patterns (they should be
       quoted  to  preserve them from being interpreted as
       glob patterns),  and  the  aliases  matching  these
       patterns  are  printed.   When printing aliases and
       the -g or -r flags are present, then  restrict  the
       printing    to    global    or   regular   aliases,
       respectively.  Using `+' instead of `-', or  ending
       the  option  list  with  a single `+', prevents the
       values of the aliases from being printed.

       If the -L flag is present, then print each alias in
       a  manner suitable for putting in a startup script.
       The exit status is  nonzero  if  a  name  (with  no
       value)  is  given  for  which  no  alias  has  been
       defined.
