gistfile1.txt

#!/usr/local/bin/bash

#nl2spc() {
#  sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g'
#}

#set -x

fn-args() {
  local argline=$(type $1 | grep declare | grep -v "declare desc" | head -1)
  echo -e "${argline// /"\n"}" | awk -F= '/=/{print "<"$1">"}' | tr "\n" " "
}
 
fn-desc() {
  eval "$(type $1 | grep desc | head -1)"; echo $desc
}

fn-info() {
  declare fn="$1" showsource="$2"
  echo "$fn $(fn-args $fn)"
  echo "  $(fn-desc $fn)"
  echo
  if [[ "$showsource" ]]; then
    type $fn | tail -n +2
    echo
  fi
}


declare -A CMDS

cmd-list() {
  declare desc="Lists available commands"
  declare ns="$1"
  cmd-list-keys "$ns" | sed "s/$ns://"
}

cmd-list-keys() {
  declare ns="$1"
  for k in "${!CMDS[@]}"; do
    echo "$k"
  done | grep "^$ns:" | sort
}

cmd-list-ns() {
  for k in "${!CMDS[@]}"; do
    echo "$k"
  done | grep -v : | sort
}

cmd-export() {
  declare desc="Exports a function as a command"
  declare fn="$1" as="${2:-$1}"
  local ns=""
  for n in $(cmd-list-ns); do
    echo "$fn" | grep "^$n-" &> /dev/null && ns="$n"
  done
  CMDS["$ns:${as/$ns-/}"]="$fn"
}

cmd-export-ns() {
  declare ns="$1" desc="$2"
  eval "$1() { 
    declare desc=\"$desc\"
    cmd-ns $1 \$@; 
  }"
  cmd-export "$1"
  CMDS["$1"]="$1"
}

cmd-ns() {
  local ns="$1"; shift 
  local cmd="$1"; shift || true
  if cmd-list "$ns" | grep ^$cmd\$ &> /dev/null; then
    ${CMDS["$ns:$cmd"]} $@
  else
    if [[ "$cmd" ]]; then
      echo "No such command: $cmd"
    elif [[ "$ns" ]]; then
      echo "$(fn-desc "$ns")"
    fi
    echo
    echo "Available commands:"
    for cmd in $(cmd-list "$ns"); do
      printf "  %-18s %s\n" "$cmd" "$(fn-desc "${CMDS["$ns:$cmd"]}")"
    done
    echo
    exit 2
  fi
}

cmd-help() {
  declare desc="Shows help information for a command"
  declare args="$@"
  if [[ "$args" ]]; then
    for cmd; do true; done # last arg
    local ns="${args/%$cmd/}"; ns="${ns/% /}"; ns="${ns/ /-}"
    local fn="${CMDS["$ns:$cmd"]}"
    fn-info "$fn" 1
  else
    echo
    for cmd in $(cmd-list); do 
      cmd-help "$cmd"
    done
  fi
}
cmd-export cmd-help help

cmd-export-ns sys "Internal system commands"

sys-shell() {
  declare desc="Enters interactive shell"
  PS1="prog # " bash --init-file prog
}
cmd-export sys-shell

sys-run() {
  declare desc="Run arbitrary function directly"
  declare fn="$1" args="$2"
  $fn $args
}
cmd-export sys-run


hello() {
  declare desc="Displays a friendly hello"
  declare firstname="$1" lastname="$2"
  echo "Hello, $firstname $lastname."
}
cmd-export hello


cmd-export-ns foobar "Foobar commands"

foobar-action() {
  echo "Foobar"
}
cmd-export foobar-action

foobar-action2() {
  echo "Foobar2"
}
cmd-export foobar-action2

cmd-export-ns foobar-ns "sub namespace"

foobar-ns-f1() {
  echo "f1"
}
cmd-export foobar-ns-f1
 

[[ "$0" == "$BASH_SOURCE" ]] && cmd-ns "" $@