| local _tl_compat; if (tonumber((_VERSION or ''):match('[%d.]*$')) or 0) < 5.3 then local p, m = pcall(require, 'compat53.module'); if p then _tl_compat = m end end; local io = _tl_compat and _tl_compat.io or io; local math = _tl_compat and _tl_compat.math or math; local string = _tl_compat and _tl_compat.string or string |
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| local tar = { Header = {} } |
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| local fs = require("luarocks.fs") |
| local dir = require("luarocks.dir") |
| local fun = require("luarocks.fun") |
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| local blocksize = 512 |
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| local function get_typeflag(flag) |
| if flag == "0" or flag == "\0" then return "file" |
| elseif flag == "1" then return "link" |
| elseif flag == "2" then return "symlink" |
| elseif flag == "3" then return "character" |
| elseif flag == "4" then return "block" |
| elseif flag == "5" then return "directory" |
| elseif flag == "6" then return "fifo" |
| elseif flag == "7" then return "contiguous" |
| elseif flag == "x" then return "next file" |
| elseif flag == "g" then return "global extended header" |
| elseif flag == "L" then return "long name" |
| elseif flag == "K" then return "long link name" |
| end |
| return "unknown" |
| end |
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| local function octal_to_number(octal) |
| local exp = 0 |
| local number = 0 |
| octal = octal:gsub("%s", "") |
| for i = #octal, 1, -1 do |
| local digit = math.tointeger(octal:sub(i, i)) |
| if not digit then |
| break |
| end |
| number = number + (digit * math.tointeger(8 ^ exp)) |
| exp = exp + 1 |
| end |
| return number |
| end |
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| local function checksum_header(block) |
| local sum = 256 |
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| if block:byte(1) == 0 then |
| return 0 |
| end |
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| for i = 1, 148 do |
| local b = block:byte(i) or 0 |
| sum = sum + b |
| end |
| for i = 157, 500 do |
| local b = block:byte(i) or 0 |
| sum = sum + b |
| end |
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| return sum |
| end |
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| local function nullterm(s) |
| return s:match("^[^%z]*") |
| end |
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| local function read_header_block(block) |
| local header = {} |
| header.name = nullterm(block:sub(1, 100)) |
| header.mode = nullterm(block:sub(101, 108)):gsub(" ", "") |
| header.uid = octal_to_number(nullterm(block:sub(109, 116))) |
| header.gid = octal_to_number(nullterm(block:sub(117, 124))) |
| header.size = octal_to_number(nullterm(block:sub(125, 136))) |
| header.mtime = octal_to_number(nullterm(block:sub(137, 148))) |
| header.chksum = octal_to_number(nullterm(block:sub(149, 156))) |
| header.typeflag = get_typeflag(block:sub(157, 157)) |
| header.linkname = nullterm(block:sub(158, 257)) |
| header.magic = block:sub(258, 263) |
| header.version = block:sub(264, 265) |
| header.uname = nullterm(block:sub(266, 297)) |
| header.gname = nullterm(block:sub(298, 329)) |
| header.devmajor = octal_to_number(nullterm(block:sub(330, 337))) |
| header.devminor = octal_to_number(nullterm(block:sub(338, 345))) |
| header.prefix = block:sub(346, 500) |
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| if header.typeflag == "unknown" then |
| if checksum_header(block) ~= header.chksum then |
| return nil, "Failed header checksum" |
| end |
| end |
| return header |
| end |
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| function tar.untar(filename, destdir) |
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| local tar_handle = io.open(filename, "rb") |
| if not tar_handle then return nil, "Error opening file " .. filename end |
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| local long_name, long_link_name |
| local ok, err |
| local make_dir = fun.memoize(fs.make_dir) |
| while true do |
| local block |
| repeat |
| block = tar_handle:read(blocksize) |
| until (not block) or block:byte(1) > 0 |
| if not block then break end |
| if #block < blocksize then |
| ok, err = nil, "Invalid block size -- corrupted file?" |
| break |
| end |
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| local header |
| header, err = read_header_block(block) |
| if not header then |
| ok = false |
| break |
| end |
| local file_data = "" |
| if header.size > 0 then |
| local nread = math.ceil(header.size / blocksize) * blocksize |
| file_data = tar_handle:read(header.size) |
| if nread > header.size then |
| tar_handle:seek("cur", nread - header.size) |
| end |
| end |
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| if header.typeflag == "long name" then |
| long_name = nullterm(file_data) |
| elseif header.typeflag == "long link name" then |
| long_link_name = nullterm(file_data) |
| else |
| if long_name then |
| header.name = long_name |
| long_name = nil |
| end |
| if long_link_name then |
| header.name = long_link_name |
| long_link_name = nil |
| end |
| end |
| local pathname = dir.path(destdir, header.name) |
| pathname = fs.absolute_name(pathname) |
| if header.typeflag == "directory" then |
| ok, err = make_dir(pathname) |
| if not ok then |
| break |
| end |
| elseif header.typeflag == "file" then |
| local dirname = dir.dir_name(pathname) |
| if dirname ~= "" then |
| ok, err = make_dir(dirname) |
| if not ok then |
| break |
| end |
| end |
| local file_handle |
| file_handle, err = io.open(pathname, "wb") |
| if not file_handle then |
| ok = nil |
| break |
| end |
| file_handle:write(file_data) |
| file_handle:close() |
| fs.set_time(pathname, header.mtime) |
| if header.mode:match("[75]") then |
| fs.set_permissions(pathname, "exec", "all") |
| else |
| fs.set_permissions(pathname, "read", "all") |
| end |
| end |
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| end |
| tar_handle:close() |
| return ok, err |
| end |
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| return tar |
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|
