Improve option parsing and command detection.

hosts

@@ -138,99 +138,6 @@ die() {
   _die echo "${@}"
 }
 
-###############################################################################
-# Options
-#
-# NOTE: The `getops` builtin command only parses short options and BSD `getopt`
-# does not support long arguments (GNU `getopt` does), so the most portable
-# and clear way to parse options is often to just use a `while` loop.
-#
-# For a pure bash `getopt` function, try pure-getopt:
-#   https://github.com/agriffis/pure-getopt
-#
-# More info:
-#   http://wiki.bash-hackers.org/scripting/posparams
-#   http://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
-#   http://stackoverflow.com/a/14203146
-#   http://stackoverflow.com/a/7948533
-#   https://stackoverflow.com/a/12026302
-#   https://stackoverflow.com/a/402410
-###############################################################################
-
-# Get raw options for any commands that expect them.
-_RAW_OPTIONS="${*:-}"
-
-# Parse Options ###############################################################
-
-# Initialize $_COMMAND_ARGV array
-#
-# This array contains all of the arguments that get passed along to each
-# command. This is essentially the same as the program arguments, minus those
-# that have been filtered out in the program option parsing loop. This array
-# is initialized with $0, which is the program's name.
-_COMMAND_ARGV=("${0}")
-# Initialize $_CMD and `$_USE_DEBUG`, which can continue to be blank depending
-# on what the program needs.
-_CMD=""
-_USE_DEBUG=0
-_AUTO_SUDO=0
-
-while [[ ${#} -gt 0 ]]
-do
-  __opt="${1}"
-
-  shift
-
-  case "${__opt}" in
-    -h|--help)
-      _CMD="help"
-      ;;
-    --version)
-      _CMD="version"
-      ;;
-    --debug)
-      _USE_DEBUG=1
-      ;;
-    --auto-sudo|--sudo)
-      _AUTO_SUDO=1
-      ;;
-    *)
-      # The first non-option argument is assumed to be the command name.
-      # All subsequent arguments are added to $_COMMAND_ARGV.
-      if [[ -n "${_CMD:-}" ]]
-      then
-        _COMMAND_ARGV+=("${__opt}")
-      else
-        _CMD="${__opt}"
-      fi
-      ;;
-  esac
-done
-
-# Set $_COMMAND_PARAMETERS to $_COMMAND_ARGV, minus the initial element, $0. This
-# provides an array that is equivalent to $* and $@ within each command
-# function, though the array is zero-indexed, which could lead to confusion.
-#
-# Use `unset` to remove the first element rather than slicing (e.g.,
-# `_COMMAND_PARAMETERS=("${_COMMAND_ARGV[@]:1}")`) because under bash 3.2 the
-# resulting slice is treated as a quoted string and doesn't easily get coaxed
-# into a new array.
-_COMMAND_PARAMETERS=("${_COMMAND_ARGV[@]}")
-unset "_COMMAND_PARAMETERS[0]"
-
-_debug printf \
-  "\${_CMD}: %s\\n" \
-  "${_CMD}"
-_debug printf \
-  "\${_RAW_OPTIONS} (one per line):\\n%s\\n" \
-  "${_RAW_OPTIONS}"
-_debug printf \
-  "\${_COMMAND_ARGV[*]}: %s\\n" \
-  "${_COMMAND_ARGV[*]}"
-_debug printf \
-  "\${_COMMAND_PARAMETERS[*]:-}: %s\\n" \
-  "${_COMMAND_PARAMETERS[*]:-}"
-
 ###############################################################################
 # Environment
 ###############################################################################
@@ -331,7 +238,7 @@ _main() {
   if _contains "${_CMD}" "${_DEFINED_COMMANDS[*]:-}"
   then
     # Pass all comment arguments to the program except for the first ($0).
-    ${_CMD} "${_COMMAND_PARAMETERS[@]:-}"
+    "${_CMD}" "${_COMMAND_PARAMETERS[@]:-}"
   else
     _die printf "Unknown command: %s\\n" "${_CMD}"
   fi
@@ -1478,6 +1385,120 @@ unblock() {
   done
 }
 
+###############################################################################
+# Options
+#
+# NOTE: The `getops` builtin command only parses short options and BSD `getopt`
+# does not support long arguments (GNU `getopt` does), so the most portable
+# and clear way to parse options is often to just use a `while` loop.
+#
+# For a pure bash `getopt` function, try pure-getopt:
+#   https://github.com/agriffis/pure-getopt
+#
+# More info:
+#   http://wiki.bash-hackers.org/scripting/posparams
+#   http://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
+#   http://stackoverflow.com/a/14203146
+#   http://stackoverflow.com/a/7948533
+#   https://stackoverflow.com/a/12026302
+#   https://stackoverflow.com/a/402410
+###############################################################################
+
+# Get raw options for any commands that expect them.
+_RAW_OPTIONS="${*:-}"
+
+# Parse Options ###############################################################
+
+# Initialize $_COMMAND_ARGV array
+#
+# This array contains all of the arguments that get passed along to each
+# command. This is essentially the same as the program arguments, minus those
+# that have been filtered out in the program option parsing loop. This array
+# is initialized with $0, which is the program's name.
+_COMMAND_ARGV=("${0}")
+# Initialize $_CMD and `$_USE_DEBUG`, which can continue to be blank depending
+# on what the program needs.
+_CMD=""
+_USE_DEBUG=0
+_AUTO_SUDO=0
+
+_SUBCOMMANDS=(
+  add
+  backups
+  block
+  commands
+  disable
+  disabled
+  edit
+  enable
+  enabled
+  file
+  help
+  list
+  remove
+  search
+  show
+  unblock
+  version
+)
+_SUBCOMMANDS_PATTERN="$(_join '|' "${_SUBCOMMANDS[@]}")"
+
+while [[ ${#} -gt 0 ]]
+do
+  __opt="${1}"
+
+  shift
+
+  case "${__opt}" in
+    -h|--help)
+      _CMD="help"
+      ;;
+    --version)
+      _CMD="version"
+      ;;
+    --debug)
+      _USE_DEBUG=1
+      ;;
+    --auto-sudo|--sudo)
+      _AUTO_SUDO=1
+      ;;
+    *)
+      # The first non-option argument is assumed to be the command name.
+      # All subsequent arguments are added to $_COMMAND_ARGV.
+      if [[ -z "${_CMD:-}" ]] &&  [[ "${__opt:-}" =~ ${_SUBCOMMANDS_PATTERN} ]]
+      then
+        _CMD="${__opt}"
+      else
+        _COMMAND_ARGV+=("${__opt}")
+      fi
+      ;;
+  esac
+done
+
+# Set $_COMMAND_PARAMETERS to $_COMMAND_ARGV, minus the initial element, $0. This
+# provides an array that is equivalent to $* and $@ within each command
+# function, though the array is zero-indexed, which could lead to confusion.
+#
+# Use `unset` to remove the first element rather than slicing (e.g.,
+# `_COMMAND_PARAMETERS=("${_COMMAND_ARGV[@]:1}")`) because under bash 3.2 the
+# resulting slice is treated as a quoted string and doesn't easily get coaxed
+# into a new array.
+_COMMAND_PARAMETERS=("${_COMMAND_ARGV[@]}")
+unset "_COMMAND_PARAMETERS[0]"
+
+_debug printf \
+  "\${_CMD}: %s\\n" \
+  "${_CMD}"
+_debug printf \
+  "\${_RAW_OPTIONS} (one per line):\\n%s\\n" \
+  "${_RAW_OPTIONS}"
+_debug printf \
+  "\${_COMMAND_ARGV[*]}: %s\\n" \
+  "${_COMMAND_ARGV[*]}"
+_debug printf \
+  "\${_COMMAND_PARAMETERS[*]:-}: %s\\n" \
+  "${_COMMAND_PARAMETERS[*]:-}"
+
 ###############################################################################
 # Run Program
 ###############################################################################