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Diffstat (limited to 'include/dnsjit/lib/getopt.lua')
| -rw-r--r-- | include/dnsjit/lib/getopt.lua | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/include/dnsjit/lib/getopt.lua b/include/dnsjit/lib/getopt.lua new file mode 100644 index 0000000..ede3e12 --- /dev/null +++ b/include/dnsjit/lib/getopt.lua @@ -0,0 +1,368 @@ +-- Copyright (c) 2018-2021, OARC, Inc. +-- All rights reserved. +-- +-- This file is part of dnsjit. +-- +-- dnsjit is free software: you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation, either version 3 of the License, or +-- (at your option) any later version. +-- +-- dnsjit is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with dnsjit. If not, see <http://www.gnu.org/licenses/>. + +-- dnsjit.lib.getopt +-- Parse and handle arguments +-- local getopt = require("dnsjit.lib.getopt").new({ +-- { "v", "verbose", 0, "Enable verbosity", "?+" }, +-- { nil, "host", "localhost", "Set host", "?" }, +-- { "p", nil, 53, "Set port", "?" }, +-- }) +-- . +-- local left = getopt:parse() +-- . +-- print("host", getopt:val("host")) +-- print("port", getopt:val("p")) +-- +-- A "getopt long" implementation to easily handle command line arguments +-- and display usage. +-- An option is the short name (one character), long name, +-- default value (which also defines the type), help text and extensions. +-- Options are by default required, see extensions to change this. +-- .LP +-- The Lua types allowed are +-- .BR boolean , +-- .BR string , +-- .BR number . +-- .LP +-- The extensions available are: +-- .TP +-- .B ? +-- Make the option optional. +-- .TP +-- .B * +-- For string and number options this make it possible to specified it +-- multiple times and all values will be returned in a table. +-- .TP +-- .B + +-- For number options this will act as an counter increaser, the value will +-- be the default value + 1 for each time the option is given. +-- .LP +-- Option +-- .I -h +-- and +-- .I --help +-- are automatically added if the option +-- .I --help +-- is not already defined. +-- .SS Attributes +-- .TP +-- left +-- A table that contains the arguments left after parsing, same as returned by +-- .IR parse() . +-- .TP +-- usage_desc +-- A string that describes the usage of the program, if not set then the +-- default will be " +-- .I "program [options...]" +-- ". +module(...,package.seeall) + +local log = require("dnsjit.core.log") + +local module_log = log.new("lib.getopt") +Getopt = {} + +-- Create a new Getopt object. +-- .I args +-- is a table with tables that specifies the options available. +-- Each entry is unpacked and sent to +-- .BR Getopt:add() . +function Getopt.new(args) + local self = setmetatable({ + left = {}, + usage_desc = nil, + _opt = {}, + _s2l = {}, + _log = log.new("lib.getopt", module_log), + }, { __index = Getopt }) + + self._log:debug("new()") + + for k, v in pairs(args) do + local short, long, default, help, extensions = unpack(v) + self:add(short, long, default, help, extensions) + end + + return self +end + +-- Return the Log object to control logging of this instance or module. +function Getopt:log() + if self == nil then + return module_log + end + return self._log +end + +-- Add an option. +function Getopt:add(short, long, default, help, extensions) + local optional = false + local multiple = false + local counter = false + local name = long or short + + if type(name) ~= "string" then + error("long|short) need to be a string") + elseif name == "" then + error("name (long|short) needs to be set") + end + if short and (type(short) ~= "string" or #short ~= 1) then + error("short needs to be a string of length 1") + end + + if self._opt[name] then + error("option "..name.." alredy exists") + elseif short and self._s2l[short] then + error("option "..short.." alredy exists") + end + + local t = type(default) + if t ~= "string" and t ~= "number" and t ~= "boolean" then + error("option "..name..": invalid type "..t) + end + + if type(extensions) == "string" then + local n + for n = 1, extensions:len() do + local extension = extensions:sub(n, n) + if extension == "?" then + optional = true + elseif extension == "*" then + multiple = true + elseif extension == "+" then + counter = true + else + error("option "..name..": invalid extension "..extension) + end + end + end + + self._opt[name] = { + value = nil, + short = short, + long = long, + type = t, + default = default, + help = help, + optional = optional, + multiple = multiple, + counter = counter, + } + if long and short then + self._s2l[short] = long + elseif short and not long then + self._s2l[short] = short + end + + if not self._opt["help"] then + self._opt["help"] = { + short = nil, + long = "help", + type = "boolean", + default = false, + help = "Display this help text", + optional = true, + } + if not self._s2l["h"] then + self._opt["help"].short = "h" + self._s2l["h"] = "help" + end + end +end + +-- Print the usage. +function Getopt:usage() + if self.usage_desc then + print("usage: " .. self.usage_desc) + else + print("usage: program [options...]") + end + + local opts = {} + for k, _ in pairs(self._opt) do + if k ~= "help" then + table.insert(opts, k) + end + end + table.sort(opts) + table.insert(opts, "help") + + for _, k in pairs(opts) do + local v = self._opt[k] + local arg + if v.type == "string" then + arg = " \""..v.default.."\"" + elseif v.type == "number" and v.counter == false then + arg = " "..v.default + else + arg = "" + end + if v.long then + print("", (v.short and "-"..v.short or " ").." --"..v.long..arg, v.help) + else + print("", "-"..v.short..arg, v.help) + end + end +end + +-- Parse the options. +-- If +-- .I args +-- is not specified or nil then the global +-- .B arg +-- is used. +-- If +-- .I startn +-- is given, it will start parsing arguments in the table from that position. +-- The default position to start at is 2 for +-- .IR dnsjit , +-- see +-- .BR dnsjit.core (3). +function Getopt:parse(args, startn) + if not args then + args = arg + end + + local n + local opt = nil + local left = {} + local need_arg = false + local stop = false + local name + for n = startn or 2, table.maxn(args) do + if need_arg then + if opt.multiple then + if opt.value == nil then + opt.value = {} + end + if opt.type == "number" then + table.insert(opt.value, tonumber(args[n])) + else + table.insert(opt.value, args[n]) + end + else + if opt.type == "number" then + opt.value = tonumber(args[n]) + else + opt.value = args[n] + end + end + need_arg = false + elseif stop or args[n] == "-" then + table.insert(left, args[n]) + elseif args[n] == "--" then + stop = true + elseif args[n]:sub(1, 1) == "-" then + if args[n]:sub(1, 2) == "--" then + name = args[n]:sub(3) + else + name = args[n]:sub(2) + if name:len() > 1 then + local n2, name2 + for n2 = 1, name:len() - 1 do + name2 = name:sub(n2, n2) + opt = self._opt[self._s2l[name2]] + if not opt then + error("unknown option "..name2) + end + if opt.type == "number" and opt.counter then + if opt.value == nil then + opt.value = opt.default + end + opt.value = opt.value + 1 + elseif opt.type == "boolean" then + if opt.value == nil then + opt.value = opt.default + end + if opt.value then + opt.value = false + else + opt.value = true + end + else + error("invalid short option '"..name2.."' in multioption statement") + end + end + name = name:sub(-1) + end + end + if self._s2l[name] then + name = self._s2l[name] + end + if not self._opt[name] then + error("unknown option "..name) + end + opt = self._opt[name] + if opt.type == "string" then + need_arg = true + elseif opt.type == "number" then + if opt.counter then + if opt.value == nil then + opt.value = opt.default + end + opt.value = opt.value + 1 + else + need_arg = true + end + elseif opt.type == "boolean" then + if opt.value == nil then + opt.value = opt.default + end + if opt.value then + opt.value = false + else + opt.value = true + end + else + error("internal error, invalid option type "..opt.type) + end + else + table.insert(left, args[n]) + end + end + + if need_arg then + error("option "..name.." needs argument") + end + + for k, v in pairs(self._opt) do + if v.optional == false and v.value == nil then + error("missing required option "..k.."") + end + end + + self.left = left + return left +end + +-- Return the value of an option. +function Getopt:val(name) + local opt = self._opt[name] or self._opt[self._s2l[name]] + if not opt then + return + end + if opt.value == nil then + return opt.default + else + return opt.value + end +end + +-- dnsjit.core (3) +return Getopt |