Cfrtjryk

You'll have to use tmux shortcuts. Assuming your tmux command shortcut is the default: Ctrl+b, then:

1. Ctrl+b, [ Enter copy(?) mode.




2. Move to start/end of text to highlight.



3. 
   

   Ctrlspace

   
   
   

   Start highlighting text (on Arch Linux). When I've compiled tmux from source on OSX and other Linux's, just Space on its own usually works. Selected text changes the colours, so you'll know if the command worked.

   
   



4. Move to opposite end of text to copy.




5. Alt+w Copies selected text into tmux clipboard. (On Mac use Esc+w.)




6. Move cursor to opposite tmux pane, or completely different tmux window. Put the cursor where you want to paste the text you just copied.




7. Ctrl+b, ] Paste copied text from tmux clipboard.

tmux is quite good at mapping commands to custom keyboard shortcuts.

See Ctrl+b,? for the full list of set keyboard shortcuts.

Unfortunately, I can't add a comment yet to Alex Leach's answer so I'm going to include an addendum here for Mac OS X users:

5. 
   Enter Copies the selected text

If you are using vim and tmux on macOS (Tested on macOS 10.12.2, tmux 2.3):

(Assume that prefix key combination of tmux is prefix. The prefix is ctrl + b in defaults.)

• Copy:
  
  
  
  
  1. Press prefix + [ to enter copy mode.
  
  
  2. Use arrow keys to go to the start/end of text selection.
  
  
  3. Press ctrl + space (If you have set ctrl + space as prefix, Press ctrl + space + space instead)
  
  
  4. Use arrow keys to move to the other side of selection.
  
  
  5. Press ctrl + w.
  
  
  
  


• Paste:
  
  
  
  
  1. Press prefix + ] in insert mode.
  
  
  
  

You could use the system clip board with "*y and "*p instead of the normal y and p.

If you have vim open, its better to use the vim copy paste to copy text.

Tmux copy paste will work, however there are several disadvantages.

First, when copying multiple lines of text, you will have to select multiple lines. Tmux copy paste typically doesnt understand that vim has line numbers or there are markings in the vim gutter (such as relative numbers/absolute numbers). As a result, it will copy those as well.

Secondly, I have found that if the text has certain language specific formatting, and you directly try to copy paste using tmux to vim, it will mess up the formatting. This can be avoided by using set paste!. However, this requires a lot more work.

Use "+y to copy and "+p to paste

Vim natively provides a method to copy paste between the vim buffer and the system clipboard, using either "+y or "*y. Then pasting using "+p or "*p. This will avoide copying the relative numbers in the gutter or other random marks which are not relevant to vim

I am connecting to my CentOS server on a Windows machine using ZOC terminal ssh client. Here is what works for me:

• Enter copy mode: <prefix>+[
  


• Start copy: <Space>
  


• Copy text: <Enter>
  


• Paste text: <prefix>+]
  

A couple of options for vim use since the tmux shortcut sequence is bit long and I find it hard to remember

Like the answers above said you can use "+y and "*y to copy and then "+p and "*p respectively to paste. If you want vim to use the clipboard by default so you can just use y/p directly then.

set clipboard=unamed "sets the default copy register to be *

set clipboard=unamedplus "sets the default copy register to be +

source for clipboard command: https://vi.stackexchange.com/questions/84/how-can-i-copy-text-to-the-system-clipboard-from-vim