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, define a
       global alias; global aliases are expanded even if they do not oc-
       cur 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 different
       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, regu-
       lar 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).