--[[ POSIX library for Lua 5.1, 5.2 & 5.3. Copyright (C) 2013-2018 Gary V. Vaughan Copyright (C) 2010-2013 Reuben Thomas Copyright (C) 2008-2010 Natanael Copa ]] --[[-- Lua POSIX bindings. In addition to the convenience functions documented in this module, many APIs from submodules are copied into the return table for backwards compatibility and, if necessary, wrapped to match the deprecated API. This means that your old code will continue to work, but that you can use the improved documented APIs in new code. @module posix ]] local _ENV = require 'std.normalize' { 'bit32.bor', 'os.exit', 'posix._base.argscheck', 'posix.errno.errno', 'posix.errno.set_errno', 'posix.fcntl.O_RDWR', 'posix.fcntl.O_NOCTTY', 'posix.fcntl.open', 'posix.glob.GLOB_MARK', 'posix.glob.glob', 'posix.stdlib.grantpt', 'posix.stdlib.openpt', 'posix.stdlib.ptsname', 'posix.stdlib.unlockpt', 'posix.sys.stat.stat', 'posix.sys.wait.wait', 'posix.unistd.STDIN_FILENO', 'posix.unistd.STDOUT_FILENO', 'posix.unistd._exit', 'posix.unistd.access', 'posix.unistd.close', 'posix.unistd.dup2', 'posix.unistd.execp', 'posix.unistd.fork', 'posix.unistd.getegid', 'posix.unistd.geteuid', 'posix.unistd.getgid', 'posix.unistd.getuid', 'posix.unistd.pipe', 'string.gsub', 'string.match', 'string.sub', 'table.insert', 'table.remove', } -- FIXME: specl-14.x breaks function environments here :( local GLOB_MARK, STDIN_FILENO, STDOUT_FILENO, _exit, close, errno, execp, exit, fork, glob, pipe, wait = GLOB_MARK, STDIN_FILENO, STDOUT_FILENO, _exit, close, errno, execp, exit, fork, glob, pipe, wait local function Peuidaccess(file, mode) local euid, egid = geteuid(), getegid() if getuid() == euid and getgid() == egid then -- If we are not set-uid or set-gid, access does the same. return access(file, mode) end local stats = stat(file) if not stats then return end -- The super-user can read and write any file, and execute any file -- that anyone can execute. if euid == 0 and((not match(mode, 'x')) or match(stats.st_mode, 'x')) then return 0 end -- Convert to simple list of modes. mode = gsub(mode, '[^rwx]', '') if mode == '' then return 0 -- The file exists. end -- Get the modes we need. local granted = sub(stats.st_mode, 1, 3) if euid == stats.st_uid then granted = sub(stats.st_mode, 7, 9) elseif egid == stats.st_gid or set.new(posix.getgroups()):member(stats.st_gid) then granted = sub(stats.st_mode, 4, 6) end granted = gsub(granted, '[^rwx]', '') if gsub('[^' .. granted .. ']', mode) == '' then return 0 end set_errno(EACCESS) end local function Pexecx(task, ...) if type(task) == 'table' then local path = remove(task, 1) execp(path, task) -- Only get here if there's an error; kill the fork local _, n = errno() _exit(n) else -- Function call must flush open file descriptors et.al. with `os.exit()` exit(task(...) or 0) end end local function Pglob(args) -- Support previous `glob '.*'` style calls. if type(args) == 'string' then args = {pattern=args} elseif type(args) ~= 'table' then args = {} end local flags = 0 if args.MARK then flags = GLOB_MARK end return glob(args.pattern, flags) end local function Popenpty(term, win) local ok, errmsg, master, slave, slave_name master, errmsg = openpt(bor(O_RDWR, O_NOCTTY)) if master then ok, errmsg = grantpt(master) if ok then ok, errmsg = unlockpt(master) if ok then slave_name, errmsg = ptsname(master) if slave_name then slave, errmsg = open(slave_name, bor(O_RDWR, O_NOCTTY)) if slave then return master, slave, slave_name end end end end close(master) end return nil, errmsg end local function Ppclose(pfd) close(pfd.fd) for i = 1, #pfd.pids - 1 do wait(pfd.pids[i]) end local _, reason, status = wait(pfd.pids[#pfd.pids]) return reason, status end local function move_fd(from_fd, to_fd) if from_fd ~= to_fd then if not dup2(from_fd, to_fd) then error 'error dup2-ing' end close(from_fd) end end local function Ppopen(task, mode, pipe_fn) local read_fd, write_fd = (pipe_fn or pipe)() if not read_fd then error 'error opening pipe' end local parent_fd, child_fd, in_fd, out_fd if mode == 'r' then parent_fd, child_fd, in_fd, out_fd = read_fd, write_fd, STDIN_FILENO, STDOUT_FILENO elseif mode == 'w' then parent_fd, child_fd, in_fd, out_fd = write_fd, read_fd, STDOUT_FILENO, STDIN_FILENO else error 'invalid mode' end local pid = fork() if pid == nil then error 'error forking' elseif pid == 0 then -- child process move_fd(child_fd, out_fd) close(parent_fd) _exit(Pexecx(task, child_fd, in_fd, out_fd)) end -- parent process close(child_fd) return {pids={pid}, fd=parent_fd} end local function Ppopen_pipeline(tasks, mode, pipe_fn) local first, from, to, inc = 1, 2, #tasks, 1 if mode == 'w' then first, from, to, inc = #tasks, #tasks - 1, 1, -1 end local pfd = Ppopen(tasks[first], mode, pipe_fn) for i = from, to, inc do local pfd_next = Ppopen(function(fd, in_fd, out_fd) move_fd(pfd.fd, in_fd) _exit(Pexecx(tasks[i])) end, mode, pipe_fn) close(pfd.fd) pfd.fd = pfd_next.fd insert(pfd.pids, pfd_next.pids[1]) end return pfd end local function Pspawn(task, ...) local pid, err = fork() if pid == nil then return pid, err elseif pid == 0 then Pexecx(task, ...) else local _, reason, status = wait(pid) return status, reason -- If wait failed, status is nil & reason is error end end local function Ptimeradd(x, y) local sec, usec = 0, 0 if x.tv_sec or x.tv_usec then sec = sec +(tonumber(x.tv_sec) or 0) usec = usec +(tonumber(x.tv_usec) or 0) else sec = sec +(tonumber(x.sec) or 0) usec = usec +(tonumber(x.usec) or 0) end if y.tv_sec or y.tv_usec then sec = sec +(tonumber(y.tv_sec) or 0) usec = usec +(tonumber(y.tv_usec) or 0) else sec = sec +(tonumber(y.sec) or 0) usec = usec +(tonumber(y.usec) or 0) end while usec > 1000000 do sec = sec + 1 usec = usec - 1000000 end return {sec=sec, usec=usec} end local function Ptimercmp(x, y) local x = {sec=x.tv_sec or x.sec or 0, usec=x.tv_usec or x.usec or 0} local y = {sec=y.tv_sec or y.sec or 0, usec=y.tv_usec or y.usec or 0} if x.sec ~= y.sec then return x.sec - y.sec else return x.usec - y.usec end end local function Ptimersub(x,y) local sec, usec = 0, 0 if x.tv_sec or x.tv_usec then sec =(tonumber(x.tv_sec) or 0) usec =(tonumber(x.tv_usec) or 0) else sec =(tonumber(x.sec) or 0) usec =(tonumber(x.usec) or 0) end if y.tv_sec or y.tv_usec then sec = sec -(tonumber(y.tv_sec) or 0) usec = usec -(tonumber(y.tv_usec) or 0) else sec = sec -(tonumber(y.sec) or 0) usec = usec -(tonumber(y.usec) or 0) end while usec < 0 do sec = sec - 1 usec = usec + 1000000 end return { sec = sec, usec = usec } end -- For backwards compatibility, copy all table entries into M namespace. local M = {} do for _, name in ipairs { 'ctype', 'dirent', 'errno', 'fcntl', 'fnmatch', 'glob', 'grp', 'libgen', 'poll', 'pwd', 'sched', 'signal', 'stdio', 'stdlib', 'sys.msg', 'sys.resource', 'sys.socket', 'sys.stat', 'sys.statvfs', 'sys.time', 'sys.times', 'sys.utsname', 'sys.wait', 'syslog', 'termio', 'time', 'unistd', 'utime' } do local t = require('posix.' .. name) for k, v in pairs(t) do if k ~= 'version' then assert(M[k] == nil, 'posix namespace clash: ' .. name .. '.' .. k) M[k] = v end end end -- Inject deprecated APIs(overwriting submodules) for backwards compatibility. for k, v in pairs(require 'posix.deprecated') do M[k] = v end for k, v in pairs(require 'posix.compat') do M[k] = v end end local function merge(t, r) for k, v in next, t do r[k] = r[k] or v end return r end return setmetatable(merge(M, { --- Close a pipeline opened with popen or popen_pipeline. -- @function pclose -- @tparam table pfd pipeline object -- @return values as for @{posix.sys.wait.wait}, for the last (or only) -- stage of the pipeline pclose = argscheck('pclose(table)', Ppclose), --- Check permissions like @{posix.unistd.access}, but for euid. -- Based on the glibc function of the same name. Does not always check -- for read-only file system, text busy, etc., and does not work with -- ACLs &c. -- @function euidaccess -- @string file file to check -- @string mode checks to perform (as for access) -- @return 0 if access allowed; nil otherwise (and errno is set) euidaccess = argscheck('euidaccess(string, string)', Peuidaccess), --- Exec a command or Lua function. -- @function execx -- @tparam table task argument list for @{posix.unistd.execp} or a Lua -- function, which should read from standard input, write to standard -- output, and return an exit code -- @param ... positional arguments to the function -- @treturn nil on error(normally does not return) -- @treturn string error message execx = argscheck('execx(function|table, ?any...)', Pexecx), --- Find all files in this directory matching a shell pattern. -- The flag MARK appends a trailing slash to matches that are directories. -- @function glob -- @tparam table|string|nil args the three possible parameters can be used to -- override the default values for `pattern` and `MARK`, which are `"*"` and -- `false` respectively. A table will be checked for optional keys `pattern` -- and `MARK`. A string will be used as the glob pattern. -- @treturn table matching files and directories glob = argscheck('glob(?string|table)', Pglob), --- Open a pseudo-terminal. -- Based on the glibc function of the same name. -- @function openpty -- @fixme add support for term and win arguments -- @treturn[1] int master file descriptor -- @treturn[1] int slave file descriptor -- @treturn[1] string slave file name -- @return[2] nil -- @treturn[2] string error message openpty = argscheck('openpty()', Popenpty), --- Run a commands or Lua function in a sub-process. -- @function popen -- @tparam table task argument list for @{posix.unistd.execp} or a Lua -- function, which should read from standard input, write to standard -- output, and return an exit code -- @tparam string mode `"r"` for read or `"w"` for write -- @func[opt] pipe_fn function returning a paired read and -- write file descriptor (*default* @{posix.unistd.pipe}) -- @treturn pfd pipeline object -- @see posix.execx -- @see posix.spawn popen = argscheck('popen(function|table, string, ?function)', Ppopen), --- Perform a series of commands and Lua functions as a pipeline. -- @function popen_pipeline -- @tparam table t tasks for @{posix.execx} -- @tparam string mode `"r"` for read or `"w"` for write -- @func[opt] pipe_fn function returning a paired read and -- write file descriptor (*default* @{posix.unistd.pipe}) -- @treturn pfd pipeline object popen_pipeline = argscheck('popen_pipeline(function|table, string, ?function)', Ppopen_pipeline), --- Run a command or function in a sub-process using @{posix.execx}. -- @function spawn -- @tparam table task argument list for @{posix.unistd.execp} or a Lua -- function, which should read from standard input, write to standard -- output, and return an exit code -- @param ... as for @{posix.execx} -- @return values as for @{posix.sys.wait.wait} spawn = argscheck('spawn(function|table, ?any...)', Pspawn), --- Add one gettimeofday() returned timeval to another. -- @function timeradd -- @param x a timeval -- @param y another timeval -- @return x + y, adjusted for usec overflow timeradd = argscheck('timeradd(table, table)', Ptimeradd), --- Compare one gettimeofday() returned timeval with another -- @function timercmp -- @param x a timeval -- @param y another timeval -- @return 0 if x and y are equal, >0 if x is newer, <0 if y is newer timercmp = argscheck('timercmp(table, table)', Ptimercmp), --- Subtract one gettimeofday() returned timeval from another. -- @function timersub -- @param x a timeval -- @param y another timeval -- @return x - y, adjusted for usec underflow timersub = argscheck('timersub(table, table)', Ptimersub), }), { --- Metamethods -- @section metamethods --- Lazy loading of luaposix modules. -- Don't load everything on initial startup, wait until first attempt -- to access a submodule, and then load it on demand. -- @function __index -- @string name submodule name -- @treturn table|nil the submodule that was loaded to satisfy the missing -- `name`, otherise `nil` if nothing was found -- @usage -- local version = require 'posix'.version __index = function(self, name) local ok, t = pcall(require, 'posix.' ..name) if ok then rawset(self, name, t) return t end end, })