Where is the help function defined or located?

Question

I'm trying to find where the help function/command is defined.
So far I tried:

:verbose function help

but since the h isn't in uppercase, it doesn't work (not sure if it's even a function at this point...)

Tried:

:verbose command help

This reports that it's not user-defined, though it's obvious since it's in the default Vim.

Last, I tried going into the /usr/share/vim/ directory, and running a mass grep script to search for any string/and or file that have function! help, help etc.

I looked into the Vim manual but I am not sure I found anything so far. Any (no pun intended) help would be appreciated.

Answer 1

The :help command, just like every other built-in commands, is defined in the C code that is compiled into the Vim binary.

You can find in src/ex_cmds.c in the Vim source code.

(Note also that user-defined commands are only allowed to start with an uppercase, precisely to separate them from built-in commands. Also, functions and commands are completely separate namespaces, a function needs to be evaluated with :call or as part as an expression, while a command is directly invoked after the : that puts you in Ex mode.)