How can I switch from forward to backward in Interactive search/replace regex in Vim?

Question

For example I have some text:

    'y'     to substitute this match
    'l'     to substitute this match and then quit ("last")
    'n'     to skip this match
    <Esc>   to quit substituting
    'a'     to substitute this and all remaining matches {not in Vi}
    'q'     to quit substituting {not in Vi}

and by :%s/substitute/sub/gc I can interactively search/replace. If I press 'n' it goes to the next matched pattern, how can I undo 'n'? or search backwards?

In usual search mode /search_word we can skip by 'n' and 'N' is there something similar for substitute - :%s/substitute/sub/gc ?

Answer 1

Mathias Bergert's answer does the trick, if you just need do simple single word replacement, and the replacement text is always fixed. Well perhaps this is satisfied with 70% of our daily editing. If you need the power of s/.../.../ for your substitution needs, it may be not sufficient. For example, multiple words replacement, the back reference or the function expressions in the replacement part.

What I can think of is, first do a:

:s/substitute/sub/c

note, without % range and g flag.

then you just:

• press n or N for for/backwards search,
• if you think the match should be replaced, press &,
• if you did some mistake, press u

The key is, & will redo last substitution.

In this way, you can do more complex substitutions, which is hard for the simple cw like:

• s/f../&, / add a comma after all fxx words (foo, far, fur...)
• s/\v(foo)(\d+)/\=submatch(1).(submatch(2)+1)/ increment number after foo
• and so on...

Answer 2

Personally I prefer the . command over the substitute c flag, this adds much more flexibility.

Do something like this:

/substitute<cr>
cwsub<esc>

Search for "substitute", then cw (change word) to "sub" (<esc> exits insert mode)

Now you can use n and N to move and the dot . command to replace the "substitute" to "sub". With u you can even undo the last one.