better shell setup scripting

install.sh

@@ -71,27 +71,28 @@ _setup_terminal_shell() {
   _mappings_file="${_CONFIG_PATH}/lua/mappings.lua"
   # only ask for shellname if running in terminal
   if [ -t 1 ]; then
-    printf "%s\n: " "Which shell do you want to use ? [ Enter nothing for current shell ( $_CURRENT_SHELL ) ]"
-    read -r shellname
+    printf "\n%s\n" "Which shell do you want to use? (Eg. 2)"
+    printf "\t%s\n" "[ Enter nothing for current shell ( $_CURRENT_SHELL ) ]"
+    grep '^/bin/' '/etc/shells' | nl
+    read -r shellNUM
   fi
-  shellname="${shellname:-${_CURRENT_SHELL}}"
-  printf "%s\n" "$shellname"
 
-  # don't try to do any changes if given shellname is same as bash
-  if ! [ bash = "$shellname" ]; then
+  # don't try to do any changes user wants their default shell in nvim
+  if [ ! -z "$shellNUM" ]; then
+    shellpath=$(grep '^/bin/' '/etc/shells' | sed -n "$shellNUM p")
     # Reference: https://stackoverflow.com/a/4247319
-    if "${_SED}" -i'.bak' -e "s/bash/$shellname/g" "${_mappings_file}"; then
-      printf "\n%s\n" "=> Shell changed to $shellname on nvim successfully!"
+    # \( & \) will use regex brackets (for later reference with \1)
+    # ( & ) will match text brackets
+    if "${_SED}" --posix -i'.bak' -e "s=^\(map(.* \+*terminal\) \(.*)\)=\1$shellpath \2=g" "${_mappings_file}"; then
+      printf "%s\n" "=> Neovim shell changed to $shellpath successfully!"
     else
-      printf "\n%s\n" "Cannot edit with sed, edit ${_mappings_file} manually to replace bash with $shellname."
+      printf "%s\n" "Cannot edit with sed, edit ${_mappings_file} manually to replace bash with $shellpath."
     fi
     rm -f "${_mappings_file}".bak # delete backup file created by sed
-  else
-    printf "\n%s\n" "=> Shell changed to $shellname on nvim successfully!"
   fi
+    printf "%s\n\n" "=> Neovim shell will be ${shellpath:-${_CURRENT_SHELL}}"
   return 0
 }
-
 _setup_arguments() {
   # default variables to be used
   _CONFIG_PATH="${HOME}/.config/nvim"