Learning Vim from the inside

• lid .vimrc works. Many matches. Has to be main.c though as that's where C code starts from.

• Open main.c. I have set hlsearch in .vimrc to highlight matches as I find them. Searched for .vimrc inside main.c. Commented block between line 2926 and line 2934 lists all options for vim.

/
* Try to read initialization commands from the following places: * - environment variable VIMINIT * - user vimrc file (s:.vimrc for Amiga, ~/.vimrc otherwise) * - second user vimrc file ($VIM/.vimrc for Dos) * - environment variable EXINIT * - user exrc file (s:.exrc for Amiga, ~/.exrc otherwise) * - second user exrc file ($VIM/.exrc for Dos) * The first that exists is used, the rest is ignored. /

gf on options.c in README.txt took me to

• options.c:vimrc_found() called when vimrc or VIMIINIT environment variable is found.

So in theory, vim can read whatever the value of VIMINIT is set to. But typically this is one of .vimrc, .gvimrc, _vimrc or _gvimrc depending on the platform.

• lid -Sn VIMINIT lists: main.c, options.txt,starting.txt,versoin5.txt
• vim main.c
• main.c:command_line_scan(paramp) can affect this since case 'u' or case 'U' can specify an init file.
• from examining main.c: .exrc or _exrc, or value of EXINIT can also be used.

One neat feature is that if either vimrc or exrc are not owned by the calling user, 'secure' mode is set. Using :h secure in vim tells us:

"When on, ":autocmd", shell and write commands are not allowed in ".vimrc" and ".exrc" in the current directory and map commands are displayed."

by running grep -R '~/\.vimrc' . I was able to locate a starting point of main.c.

The main() function in main.c executes source_startup_scripts() in main.c. source_startup_scripts() will try to execute a startup file in this order (once a file is found, the rest are ignored):

• environment variable VIMINIT
• user vimrc file (s:.vimrc for Amiga, ~/.vimrc otherwise)
• second user vimrc file ($VIM/.vimrc for Dos)
• environment variable EXINIT
• user exrc file (s:.exrc for Amiga, ~/.exrc otherwise)
• second user exrc file ($VIM/.exrc for Dos)

It seems like "do_source" function in "ex_cmds2.c" will read ".vimrc" file passed from "source_startup_scripts" in "main.c"

I found this out by inspecting the output of: $ lid -S 'newline' ".vimrc"

Poking around "source_startup_scripts" I found EVIM_FILE constant, running:

$ lid -S 'newline' "EVIM_FILE"

I navigated to "os_unix.h", since I run linux which lists a bunch of start up files.

In "source_startup_scripts", I found, variables whose values can be looked up in os_unix.h.

What are the various startup files Vim can/will read if they exist?

• EVIM_FILE
• SYS_VIMRC_FILE
• macvim.vim #if on a mac
• USR_VIMRC_FILE
• USR_VIMRC_FILE2
• USR_VIMRC_FILE3
• USR_EXRC_FILE
• USR_EXRC_FILE2
• VIMRC_FILE
• EXRC_FILE