How can I insert a real tab character in Vim?

When I have my vimrc here:

set tabstop=2
set shiftwidth=2
set softtabstop=2
set expandtab
set smarttab

And I have supertab plugin installed. Whenever I am in insert mode I press tab, it shows the auto completion, but sometimes I would like to insert a real tab character in a string literal like. So what I mean whenever I press tab in double quotes string literal, it should input we a real tab character.

While in insert mode or command mode (the : prompt at the bottom of the editor), type CTRL + V then TAB.

Using CTRL + V signals Vim that it should take the next character literally. Even in insert mode.

UPDATE:

As noted by Herbert Sitz, if gVim is in Windows mode (default), you must use CRTL + Q in place of CTRL + V.

@Samnang: I have a similar setup as you; unfortunately, Jason's answer did not work, for me.

This is a workaround:

• Substitute some character (e.g. a backtick: `) or characters (e.g. a unique alphanumeric string: zzz) where you want your tab(s)

• Select the text (Visual mode) and do a search/replace,

  :'<,'>s/`/\t/g

---

Updated answer, inspired by @Cyryl1972 's comment.

Insert tab at beginning of all lines (note also: no need to select lines, for any of the following code, as that's included in the line matching part of the expression):

:1,$s/^/\t\1/

Inert tab after first 10 characters in all lines:

:1,$s/^\(.\{10}\)/\1\t/

Explanation - first part:

:1,$      Match from line 1 to end of file
^(.{10}   Collect (preserve) all text from beginning of line to position 10
          (you need to escape the parentheses, \( and \), as well the FIRST
          (left) curly brace, only: \{ -- as it, { , appears to have special
          meaning in regex when used for this purpose

Explanation - second part:

/1        Add back the preserved text
\t        Insert a tab

... and the rest of the line is automatically restored, as well.

Current line, only:

:s/^/\t\1/

Example: insert tab at position 10 (0-indexed) at lines 2-4:

1234567890abcdefghij 
1234567890abcdefghij 
1234567890abcdefghij 
1234567890abcdefghij 
1234567890abcdefghij 

:2,4s/^\(.\{10}\)/\1\t/

1234567890abcdefghij 
1234567890	abcdefghij 
1234567890	abcdefghij 
1234567890	abcdefghij 
1234567890abcdefghij 

References (StackOverflow):

• https://stackoverflow.com/questions/43769148/replace-character-in-specific-position-with-another-character-using-regular-expr
• https://stackoverflow.com/questions/31841350/how-do-i-add-a-character-at-a-specific-postion-in-a-string

References (other):

• Regex Cheat Sheet