Why the -b(binary) option doesn't work in vim?

Question

As vim doc said, I can use the -b option to open a binary file.

---

-b      Binary mode.  File I/O will only recognize <NL> to separate
        lines.  The 'expandtab' option will be reset.  The 'textwidth'
        option is set to 0.  'modeline' is reset.  The 'binary' option
        is set.  This is done after reading the vimrc/exrc files but
        before reading any file in the arglist.  See also
        |edit-binary|.  {not in Vi}

---

I use this command to open vim:

$ vim --cmd 'set et' -u NONE -b

---

I type this command to view options:

:set et? bin?

  expandtab
  binary

---

The et ( expandtab ) option wasn't reset. Why?
Thanks for your help!

Answer 1

Well the issue is, simply, that --cmd -c or +cmd arguments are executed after processing the other flags. This makes sense, as it would not effectively do anything otherwise.

 :verbose set et?

would tell you exactly that. In case you need a workaround for your particular sample vim +'set binary' (unlikely since et != binary)

You are right on the docs for --cmd. So it comes down to the order in which command line flags are interpreted, which is basically 'undefined'. Although

This is done after reading the vimrc/exrc files but before reading any file in the arglist

could be taken to imply 'before processing other command line arguments'.

Note The '+' commands essentially go with specific files and are (AFAICT) processed in the order in which they appear, even when intermixed with filename arguments.