Vim: Map ctrl+pgup and ctrl+pgdn (CTRL+Page Up/Down) key combinations

I'm trying to map Vim commands to the ctrl+pgup and ctrl+pgdn key combinations. The vim syntax for these keys does not work (i.e., <PageUp> and <PageDown>, or <C-PageUp> and <C-PageDown>).

Since the default vim syntax doesn't work, I'm guessing that the Terminal isn't sending the character codes for ctrl+pgup and ctrl+pgdn which Vim is expecting. If that's true, I'm not sure how to find out what the literal key codes are. I'm using xfce4-terminal on Arch Linux.

Here's what I've tried:

The usual method:
```
map <C-PageUp> :bp<cr>
```
Setting it from the command line with this answer's method: Why <C-PageUp> and <C-PageDown> not work in vim?
```
:map <CTRL-V><CTRL-PAGEUP> :bp<cr>
```
When I type the command above in the command line, nothing shows:
```
map  :bp<cr>
```
And Vim says No mapping found.
This method from the Vim wiki: http://vim.wikia.com/wiki/Mapping_keys_in_Vim_-Tutorial(Part_2)#Key_notation
```
set <PageUp>=<type Ctrl-V><type PageUp> "^[[5~
map <C-PageUp> :bp<cr>
```

A modification of that answer:

set <C-PageUp>=<type Ctrl-V><type Ctrl+PageUp> "^M
map <C-PageUp> :bp<cr>

After realizing that <type *> was a user command, I did these commands, and vim pasted output. I replaced <type *> with this output:

set <PageUp>=^[[5~
map <C-PageUp> :bp<cr>
" Also:
set <PageUp>=[[5~
map <C-PageUp> :bp<cr>
" Also:
set <PageUp>=<^[[5~>
map <C-PageUp> :bp<cr>
" Also:
set <PageUp>=<[[5~>
map <C-PageUp> :bp<cr>
" Also:
set <C-PageUp>=^M
map <C-PageUp> :bp<cr>
" Also:
set <C-PageUp>=<^M>
map <C-PageUp> :bp<cr>

Trying all of the methods in 5, but without setting an option first. E.g.:
```
map <C-[[5~> :bp<cr>
```
The method from this answer: https://groups.google.com/forum/#!topic/vim_use/j85-2xQkb7s
```
map [5~ :bp<cr>
```
The method from this answer: https://superuser.com/questions/322983/how-to-let-ctrl-page-down-switch-tabs-inside-vim-in-terminal-app
```
 map \033[5;5~ :bp<cr>
```
Setting different term options:
```
 set term=xterm
 " Also:
 set term=xterm-256color
```
My $TERM environment variable is set to xterm.
Using some of the methods which this answer hints at: https://superuser.com/questions/480215/how-to-map-pagedown-and-pageup-keys-to-function-normally
```
 map <Esc>[5~ :bp<cr>
 map <kpp> :bp<cr>
```
Trying everything above with a file under .vim/after/plugin/ instead of in .vimrc.
Trying everything above with :MBEbp instead of :bp.

What else can I try?

Solution

Alright, I figured it out. I was overlooking something extremely simple, which is usually the case for me.

ctrlpgup and ctrlpgdn were already keyboard shortcuts in xfce4-terminal itself (for switching Terminal tabs). In order to allow Vim to use these key combinations, they cannot be used by the Terminal itself. So this was an issue with xfce4-terminal, not Vim.

xfce4-terminal shortcuts can be unset with the method described here: https://unix.stackexchange.com/questions/159979/xfce4-terminal-disable-individual-shortcut

In short, here's the process:

Open ~/.config/xfce4/terminal/accels.scm and uncomment/edit the lines:
```
(gtk_accel_path "<Actions>/terminal-window/next-tab" "")
(gtk_accel_path "<Actions>/terminal-window/prev-tab" "")
```
(You can verify this change by opening a new window and clicking Tabs in the Menubar: The Previous Tab and Next Tab items should no longer display shortcuts to their right.)
Put this command in .vimrc:
```
map <C-PageUp> :bp<CR>
map <C-PageDown> :bn<CR>
```
Consider nmap instead, to restrict the shortcut to NORMAL mode.