whence [ -vcwfpamsS ] [ -x num ] name ...
       For each name, indicate how it would be interpreted if used as  a
       command name.

       If  name  is  not  an  alias, built-in command, external command,
       shell function, hashed command, or a reserved word, the exit sta-
       tus shall be non-zero, and -- if -v, -c, or -w was  passed  --  a
       message  will  be written to standard output.  (This is different
       from other shells that write that message to standard error.)

       whence is most useful when name is only the last  path  component
       of a command, i.e. does not include a `/'; in particular, pattern
       matching only succeeds if just the non-directory component of the
       command is passed.

       -v     Produce a more verbose report.

       -c     Print the results in a csh-like format.  This takes prece-
              dence over -v.

       -w     For  each  name,  print  `name: word' where word is one of
              alias, builtin, command,  function,  hashed,  reserved  or
              none,  according  as  name  corresponds  to  an  alias,  a
              built-in command, an external command, a shell function, a
              command defined with the hash builtin, a reserved word, or
              is not recognised.  This takes precedence over -v and -c.

       -f     Causes the contents of a shell function to  be  displayed,
              which  would  otherwise not happen unless the -c flag were
              used.

       -p     Do a path search for name even if it is an alias, reserved
              word, shell function or builtin.

       -a     Do a search for all occurrences  of  name  throughout  the
              command  path.   Normally  only  the  first  occurrence is
              printed.

       -m     The arguments are taken as  patterns  (pattern  characters
              should  be  quoted),  and the information is displayed for
              each command matching one of these patterns.

       -s     If a pathname contains symlinks,  print  the  symlink-free
              pathname as well.

       -S     As -s, but if the pathname had to be resolved by following
              multiple  symlinks,  the  intermediate  steps are printed,
              too.  The symlink resolved at each step might be  anywhere
              in the path.

       -x num Expand  tabs  when outputting shell functions using the -c
              option.  This has the same effect as the -x option to  the
              functions builtin.

type [ -wfpamsS ] name ...
       Equivalent to whence -v.

where [ -wpmsS ] [ -x num ] name ...
       Equivalent to whence -ca.

which [ -wpamsS ] [ -x num ] name ...
       Equivalent to whence -c.