Upgrade `_config_*` functions `config` command

cmd

@@ -101,29 +101,16 @@ command_bar() {
   _buffer "$@" && return $?
   echo "would bar: $*"
 }
-
-HELP[json]='
-## Convert to JSON String
-
-```
-'"$EXE"' json STRING
-'"$EXE"' json <<< STRING
-'"$EXE"' json < FILE
-'"$EXE"' json < <(COMMAND)
-```
-
-Converts input into JSON string using `jq` (if found) containing only
-escaped (`\\n`) line returns.'
-
-command_json() { _jsonstr "$@"; }
-
 command__hidden() {
   _filter "$@" && return $?
   echo "would run _hidden: $*"
 }
 
-# ------------------ builtin commands and functions ------------------
-#          (https://github.com/rwxrob/template-bash-command)
+############################## BOILERPLATE ###########################
+## Everything from here to the end of file can be snipped and updated
+## with latest from https://github.com/rwxrob/template-bash-command.
+
+# -------------------------- utility command -------------------------
 
 HELP[usage]='Displays a summary of usage.'
 
@@ -137,6 +124,8 @@ command_usage() {
   printf "usage: %s (%s)\n" "$EXE" "${cmds[*]}"
 }
 
+# --------------------------- help command ---------------------------
+
 HELP[help]='
 
 ```
@@ -180,6 +169,18 @@ command_help() {
   echo -e "$title\n\n$body" | "$PAGER"
 }
 
+_help_title() {
+  _filter "$@" && return $?;
+  local name="$1"
+  while IFS= read -r line; do
+    [[ $line =~ ^[:space]*$ ]] && continue
+    [[ $line =~ ^#\ (.+) ]] && echo "${BASH_REMATCH[1]}" && return 0
+    return 1
+  done <<< "${HELP[$name]}"
+}
+
+# -------------------------- readme command --------------------------
+
 HELP[readme]='
 ## Generate `README.md` File
 
@@ -203,6 +204,8 @@ command_readme() {
   echo -e "----\n\n*Autogenerated $(date)*\n"
 }
 
+# -------------------------- config command --------------------------
+
 HELP[config]='
 
 ```
@@ -210,6 +213,9 @@ HELP[config]='
 '"$EXE"' config KEY
 '"$EXE"' config KEY VALUE
 '"$EXE"' config KEY ""
+'"$EXE"' config dir
+'"$EXE"' config path [file]
+'"$EXE"' config edit [file]
 ```
 
 The `config` command is for reading, writing, and displaying standard
@@ -222,10 +228,11 @@ With no arguments outputs all the currently cached configuration
 settings. 
 
 With a single KEY argument fetches the value for that key and outputs
-it. The special `dir` KEY is reserved and always outputs the full path
-to the current configuration directory containing the `values` file. The
-special `path` KEY is reserved and always outputs the full path to the
-`values` file itself.
+it unless it is one of the following special (reserved) key names:
+
+* `dir` full path to config directory
+* `path` full path to specific config file (default: `values`) 
+* `edit` opens config file in editor (default: `editor` or `$EDITOR)
 
 With more than one argument the remaining arguments after the KEY will
 be combined into the VALUE and written to a `values` file in the
@@ -261,24 +268,24 @@ format. It is designed for ultimate simplicity, efficiency, and
 portability.'
 
 command_config() {
+  case $1 in 
+    dir)  _config_dir ;;
+    path) _config_path ;;
+    edit) _config_edit ;;
+  esac
   case $# in
-    0) _dump_config ;; 
-    1) _get_config "$@" ;;
-    *) _set_config "$@" ;;
+    0) _config_dump ;; 
+    1) _config_get "$@" ;;
+    *) _config_set "$@" ;;
   esac
 }
 
-_help_title() {
-  _filter "$@" && return $?;
-  local name="$1"
-  while IFS= read -r line; do
-    [[ $line =~ ^[:space]*$ ]] && continue
-    [[ $line =~ ^#\ (.+) ]] && echo "${BASH_REMATCH[1]}" && return 0
-    return 1
-  done <<< "${HELP[$name]}"
+_config_edit() {
+  : "${CONFIG[editor]:="${EDITOR:=vi}"}"
+  exec "${CONFIG[editor]}" "$(_config_path "${1:-values}")"
 }
 
-_config_path() {
+_config_dir() {
   local dir="$HOME/.config/$EXE"
   [[ -n "$XDG_CONFIG_HOME" ]] && dir="$XDG_CONFIG_HOME/$EXE" 
   [[ -n "$CONFIG_DIR" ]] && dir="$CONFIG_DIR"
@@ -286,24 +293,22 @@ _config_path() {
   echo "$dir"
 }
 
-_set_config() {
+_config_path() { 
+  local file=${1:-values}
+  printf "%s/%s\n" "$(_config_dir)" "$file"
+}
+
+_config_set() {
   local key="$1"; shift; local val="$*"
   val="${val//$'\n'/\\n}"
   CONFIG["$key"]="$val"
-  _write_config
+  _config_write
 }
 
-_get_config() {
-  local key="$1"
-  case $key in 
-    dir) _config_path "" ;;
-    path) _config_path values ;;
-    *) printf "${CONFIG[$key]}" ;;
-  esac
-}
+_config_get() { printf "${CONFIG[$1]}"; }
 
-_read_config() {
-  local values="$(_get_config path)"
+_config_read() {
+  local values="$(_config_path)"
   [[ -r "$values" ]] || return 0
   while IFS= read -r line; do
     [[ $line =~ ^([^=]+)=(.+)$ ]] || continue
@@ -311,29 +316,55 @@ _read_config() {
   done < "$values"
 }
 
-_write_config() {
-  local dir="$(_get_config dir)"
+_config_write() {
+  local dir="$(_config_dir)"
   mkdir -p "$dir"
-  _dump_config > "$dir/values"
+  _config_dump > "$dir/values"
 }
 
-_dump_config() {
+_config_dump() {
   (( ${#CONFIG[@]} == 0 )) && return 0
   paste -d=\
     <(printf "%s\n" "${!CONFIG[@]}") \
     <(printf "%s\n" "${CONFIG[@]}")
 }
 
-_trim() {
-  local it="${1#"${1%%[![:space:]]*}"}"
-  echo -e "${it%"${it##*[![:space:]]}"}"
-}
+# --------------------------- json command ---------------------------
+
+HELP[json]='
+## Convert to JSON String
+
+```
+'"$EXE"' json STRING
+'"$EXE"' json <<< STRING
+'"$EXE"' json < FILE
+'"$EXE"' json < <(COMMAND)
+```
+
+Converts input into JSON string using `jq` (if found) containing only
+escaped (`\\n`) line returns.'
+
+command_json() { _jsonstr "$@"; }
 
 _jsonstr() {
   _buffer "$@" && return $?
   jq -MRsc <<< "$1"
 }
 
+# ----------------------------- utilities ----------------------------
+
+_reduce() {
+  local -n name="${1:?"name of array required"}"
+  while IFS= read -r key; do
+    [[ $key =~ $2 ]] && echo "$key"
+  done < <(printf "%s\n" "${name[@]}")
+}
+
+_trim() {
+  local it="${1#"${1%%[![:space:]]*}"}"
+  echo -e "${it%"${it##*[![:space:]]}"}"
+}
+
 _have(){ type "$1" &>/dev/null; }
 
 _filter(){
@@ -373,7 +404,7 @@ for c in "${COMMANDS[@]}"; do
   fi
 done
 
-_read_config
+_config_read
 
 if [[ -n "$1" ]]; then
   declare cmd="$1"; shift