我发现用谷歌搜索是不可能的，也无法在手册页中找到信息。
最佳答案
来自 http://zsh.sourceforge.net/Doc/Release/Shell-Builtin-Commands.html :
where [ -wpms ] name ... Equivalent to whence -ca.
和:
whence [ -vcwfpams ] name ... For each name, indicate how it would be interpreted if used as a command name.
-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, 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 (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.
关于shell - zsh 内置的 "where"的目的是什么？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/29245718/