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
       status  shall be non-zero, and -- if -v, -c, or -w was passed --
       a message will be written to standard output.  (This is  differ-
       ent  from  other  shells that write that message to standard er-
       ror.)

       whence is most useful when name is only the last path  component
       of  a  command, i.e. does not include a `/'; in particular, pat-
       tern 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
              precedence 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, re-
              served 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 follow-
              ing  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.