alias [ {+|-}gmrsL ] [ 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, de-
       fine a global alias; global aliases are expanded even if they do
       not occur in command position:

              % perldoc --help 2>&1 | grep 'built-in functions'
                  -f   Search Perl built-in functions
              % alias -g HG='--help 2>&1 | grep'
              % perldoc HG 'built-in functions'
                  -f   Search Perl built-in functions

       If the -s flag is present, define a suffix alias: if the command
       word on a command line is in the form `text.name', where text is
       any  non-empty  string,  it  is  replaced  by  the  text  `value
       text.name'.  Note that name is treated as a literal string,  not
       a  pattern.   A  trailing  space in value is not special in this
       case.  For example,

              alias -s ps='gv --'

       will cause the command `*.ps' to be expanded to  `gv  --  *.ps'.
       As  alias  expansion  is  carried out earlier than globbing, the
       `*.ps' will then be expanded.  Suffix aliases constitute a  dif-
       ferent name space from other aliases (so in the above example it
       is still possible to create an alias for the command ps) and the
       two sets are never listed together.

       For  each  name  with no value, print the value of name, if any.
       With no arguments, print all  currently  defined  aliases  other
       than  suffix 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  one  of
       the  -g,  -r  or  -s  flags is present, restrict the printing to
       global, regular or suffix aliases, respectively; a regular alias
       is one which is neither a global nor a suffix alias.   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.

       For more on aliases, include common problems,  see  the  section
       ALIASING in zshmisc(1).