More detailed comparison within a line

Question

I use vimdiff to inspect differences between files, and some times it misses out a bit. for example, if I have the following two files:

//a.c
printf("Hello\n");

and:

//b.c
int i = printf("hello\n") + 3;

showing them in vimdiff gives:

What I will want to see is that in b.c the h is not capitalized.

Is there a way to tell vimdiff to compare (in that line) just part of it (I mean, ignore the int i = and the + 3)?

Answer 1

I don't think this can be done by Vim itself. From :h view-diffs (emphasis mine):

hl-DiffText   DiffText        Changed text inside a Changed line.  Vim
                                finds the first character that is different,
                                and the last character that is different
                                (searching from the end of the line).  The
                                text in between is highlighted.  This means
                                that parts in the middle that are still the
                                same are highlighted anyway.  Only "iwhite" of
                                'diffopt' is used here.

---

Tokoyami's suggestion takes us one step closer. Install diffchar (Github link for those using a plugin autoloader). Since v4.7, with the plugin enabled, Vim automatically shows more exact differences:

• You can press F7 (the default keymap) to toggle between the usual and the plugin. Reassign with:

  nmap <silent> <key> <Plug>ToggleDiffCharAllLines
  

  replacing <key> with an appropriate key code.

• You can use more colors:

  let g:DiffColors=100