Changing cursor style based on mode in both zsh and vim

I think it's better to use precmd() instead of preexec():

# .zshrc

_fix_cursor() {
   echo -ne '\e[5 q'
}

precmd_functions+=(_fix_cursor)

This way:

• you don't have to change .vimrc
• cursor is fixed also when you create a new prompt without executing a command
• you don't have to write echo -ne '\e[5 q' twice in your .zshrc.

I have found a solution:

I put this in my ~/.vimrc:

autocmd VimEnter * silent exec "! echo -ne '\e[1 q'"
autocmd VimLeave * silent exec "! echo -ne '\e[5 q'" 

This works perfectly for me, it's taken from here: https://gist.github.com/LukeSmithxyz/e62f26e55ea8b0ed41a65912fbebbe52

# vi mode
bindkey -v
export KEYTIMEOUT=1

# Change cursor shape for different vi modes.
function zle-keymap-select {
  if [[ ${KEYMAP} == vicmd ]] ||
     [[ $1 = 'block' ]]; then
    echo -ne '\e[1 q'
  elif [[ ${KEYMAP} == main ]] ||
       [[ ${KEYMAP} == viins ]] ||
       [[ ${KEYMAP} = '' ]] ||
       [[ $1 = 'beam' ]]; then
    echo -ne '\e[5 q'
  fi
}
zle -N zle-keymap-select
zle-line-init() {
    zle -K viins # initiate `vi insert` as keymap (can be removed if `bindkey -V` has been set elsewhere)
    echo -ne "\e[5 q"
}
zle -N zle-line-init
echo -ne '\e[5 q' # Use beam shape cursor on startup.
preexec() { echo -ne '\e[5 q' ;} # Use beam shape cursor for each new prompt.

You can customise the type of cursor you want (blinking or not, |, rectangle or _) by changing the numbers in the following sequences \e[5 q (5 is for beam, 1 is for block) as follows:

Set cursor style (DECSCUSR), VT520.
0  ⇒  blinking block.
1  ⇒  blinking block (default).
2  ⇒  steady block.
3  ⇒  blinking underline.
4  ⇒  steady underline.
5  ⇒  blinking bar, xterm.
6  ⇒  steady bar, xterm.