install.sh: Use chsh instead of grep /etc/shells

install.sh

@@ -21,7 +21,7 @@ _check_install_dependencies() {
     printf "%s\n" "Error: Install ${1} before proceeding."
     exit 1
   }
-  _GIT="$(command -v git)" || _error_dependencies git
+  command -v git 1>/dev/null || _error_dependencies git
   _SED="$(command -v sed)" || _error_dependencies sed
   return 0
 }
@@ -71,26 +71,29 @@ _setup_terminal_shell() {
   _mappings_file="${_CONFIG_PATH}/lua/mappings.lua"
   # only ask for shellname if running in terminal
   if [ -t 1 ]; then
-    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
+    if chsh -l 2>/dev/null 1>&2; then
+      printf "\nAvailable Shells:\n"
+      chsh -l | nl
+      printf "\n%s\n" "Which shell do you want to use? (Eg. 2)"
+      printf "\t%s\n" "[ Enter nothing for current shell ( $_CURRENT_SHELL ) ]"
+      read -r shellnum
+      [ "${shellnum}" -gt 0 ] 2>/dev/null && _SHELLPATH="$(chsh -l | sed -n "$shellnum p")"
+    fi
   fi
 
   # 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 "$shellNUM p")
+  if [ -n "$_SHELLPATH" ]; then
     # Reference: https://stackoverflow.com/a/4247319
     # \( & \) 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 $shellpath successfully!"
+    if "${_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 "%s\n" "Cannot edit with sed, edit ${_mappings_file} manually to replace bash with $shellpath."
+      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
   fi
-    printf "%s\n\n" "=> Neovim shell will be ${shellpath:-${_CURRENT_SHELL}}"
+  printf "%s\n" "=> Neovim shell will be ${_SHELLPATH:-${_CURRENT_SHELL}}"
   return 0
 }
 _setup_arguments() {