add support for bash Version 4

Author: Falco Schaffrath

generate.sh

@@ -43,8 +43,7 @@ completion+="\n{"
 completion+="\n    local cur"
 completion+="\n    local prev"
 completion+="\n"
-completion+="\n    cur=\"\${COMP_WORDS[COMP_CWORD]}\""
-completion+="\n    prev=\"\${COMP_WORDS[COMP_CWORD-1]}\""
+completion+="\n    _get_comp_words_by_ref -n : cur prev
 completion+="\n"
 completion+="\n    local -a words=("
 # generate list of commands

sfdx.bash

@@ -33,8 +33,7 @@ _sfdx()
     local cur
     local prev
 
-    cur="${COMP_WORDS[COMP_CWORD]}"
-    prev="${COMP_WORDS[COMP_CWORD-1]}"
+    _get_comp_words_by_ref -n : cur prev
 
     local -a words=(
         force:alias:list \