shim: command line library for lua.

This is a tiny Lua module that makes it easy to write utilities that work from either bash or Lua.

Usage:

Mod shim

Functions

• fn parse(v) -> args
  Parse either a string or list and convert them to key=value table. v can be either a list of {'strings', '--option=foo'} or {'strings", option='foo'} or a combination of both. If v is a string then it is split on whitespace and parsed as a list.

  Note: this handles repeat keys by creating and appending a list for that key.

• fn parseStr(str) -> args
  parses the string by splitting via whitespace. Asserts the string contains no special chars: '"[] This is for convinience, use a table if it's not enough.

  Note: if the input is already a table it just returns it.

• fn parseList(strlist) -> args
  Note: typically use parse() or parseStr() instead.
• fn short(args, short, long, value) -> nil
  Helper for dealing with -s --short arguments. Mutates args to convert short paramaters to their long counterpart.
• fn boolean(v)
  Duck type: always return a boolean (except for nil). See BOOLS (above) for mapping.
• fn boolean(v)
  Duck type: always return a boolean (except for nil). See BOOLS (above) for mapping.
• fn bools(args, ...)
• fn number(num) -> number
  Duck type: always return a number
• fn int(int) -> int
  Duck type: always return a integer.
• fn string(v)
  Duck type: always return a string This is useful for some APIs where you want to convert number/true/false to strings
  Converts nil to ''
• fn list(val, default, empty) -> {string}
  Duck type: always return a list.
  • default controls val==nil
  • empty controls val==''
• fn listSplit(val, sep)
  Duck type: if val is a string then splits it if it's a list leaves alone.
• fn file(v, default, mode--[[w+]]) -> file, error?
  Duck type: get a file handle. If v or default is a string then open the file in mode default='w+'
• fn expand(args)
  expand string keys into --key=value, ordered alphabetically. This is mostly useful for interfacing with non-lua shells.
• fn getEnvBool(k)
  return nil if env var does not exist, else boolean (true for 'true' or '1')
• fn popRaw(args, to) -> to
  pop raw arguments after '--' Removes them (including '--') from args.
• fn runSetup(args, force)
  Setup lua using require(LUA_SETUP).setup(args, force).

  The default is to use ds.setup.

• fn constructNew(Cmd, args) -> ok, err?
  The default new() constructor, handles subcommands.
• fn isCmd(R)
  Return whether a record was created with fn cmd
• fn cmd(name)
  Create a new command as your module.
  local M = shim.cmd'mycmd' {
    '...: argument documentation',
    'foo: some paramater',
    'to [path|file]: where to write output',
  }
  -- ... rest of your module.
  if shim.isMain(M) then M:main(arg) end
  return M
• fn subcmds(name)
  Create a command composed of subcommands.
• fn isMain(cmd)
  Usage: if shim.isMain(M) then os.exit(M:main(arg)) end