--[[ Copyright 2016,2019 ARATA Mizuki This file is part of ClutTeX. ClutTeX 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. ClutTeX 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 ClutTeX. If not, see . ]] local string_gsub = string.gsub local os_execute = os.execute -- s: string local function escape(s) return '"' .. string_gsub(string_gsub(s, '(\\*)"', '%1%1\\"'), '(\\+)$', '%1%1') .. '"' end -- TEST CODE assert(escape([[Hello world!]]) == [["Hello world!"]]) assert(escape([[Hello" world!]]) == [["Hello\" world!"]]) assert(escape([[Hello\" world!"]]) == [["Hello\\\" world!\""]]) -- END TEST CODE local function has_command(name) local result = os_execute("where " .. escape(name) .. " > NUL 2>&1") -- Note that os.execute returns a number on Lua 5.1 or LuaTeX return result == 0 or result == true end return { escape = escape, has_command = has_command, }