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OS

The OS module provides Operating System specific Methods

  • low level file access
  • signals
  • timers
  • asynchronous I/O
note

The OS Methods usually return 0 if OK or an OS specific negative error code.

Properties​

os.platform​

Return a string representing the platform: "linux", "darwin", "win32", "ps2" or "js".

Methods​

open​

Open a file. Return a handle or < 0 if error.

let fd = os.open(filename, flags, mode = 0o666)

Flags​

  • os.O_RDONLY
  • os.O_WRONLY
  • os.O_RDWR
  • os.O_APPEND
  • os.O_CREAT
  • os.O_EXCL
  • os.O_TRUNC
info

POSIX open flags.

close​

Close the file handle fd.

os.close(fd);

seek​

Seek in the file. Use std.SEEK_* for whence. offset is either a number or a bigint. If offset is a bigint, a bigint is returned too.

os.seek(fd, offset, whence);

read​

Read length bytes from the file handle fd to the ArrayBuffer buffer at byte position offset. Return the number of read bytes or < 0 if error.

os.read(fd, buffer, offset, length);

write​

Write length bytes to the file handle fd from the ArrayBuffer buffer at byte position offset. Return the number of written bytes or < 0 if error.

os.write(fd, buffer, offset, length);

remove​

Remove a file. Return 0 if OK or -errno.

os.remove(filename);

rename​

Rename a file. Return 0 if OK or -errno.

os.rename(oldname, newname);

realpath​

Return [str, err] where str is the canonicalized absolute pathname of path and err the error code.

os.realpath(path);

getcwd​

Return [str, err] where str is the current working directory and err the error code.

os.getcwd();

chdir​

Change the current directory. Return 0 if OK or -errno.

os.chdir(path);

mkdir​

Create a directory at path. Return 0 if OK or -errno.

os.mkdir(path, mode = 0o777);

stat​

Return [obj, err] where obj is an object containing the file status of path. err is the error code. The following fields are defined in obj: dev, ino, mode, nlink, uid, gid, rdev, size, blocks, atime, mtime, ctime. The times are specified in milliseconds since 1970.

os.stat(path);

Constants to interpret the mode property returned by stat(). They have the same value as in the C system header sys/stat.h.

  • os.S_IFMT
  • os.S_IFIFO
  • os.S_IFCHR
  • os.S_IFDIR
  • os.S_IFBLK
  • os.S_IFREG
  • os.S_IFSOCK
  • os.S_IFLNK
  • os.S_ISGID
  • os.S_ISUID

lstat​

lstat() is the same as stat() excepts that it returns information about the link itself.

os.lstat(path);

utimes​

Change the access and modification times of the file path. The times are specified in milliseconds since 1970. Return 0 if OK or -errno.

os.utimes(path, atime, mtime);

readdir​

Return [array, err] where array is an array of strings containing the filenames of the directory path. err is the error code.

os.readdir(path);

setReadHandler​

Add a read handler to the file handle fd. func is called each time there is data pending for fd. A single read handler per file handle is supported. Use func = null to remove the handler.

os.setReadHandler(fd, func);

setWriteHandler​

Add a write handler to the file handle fd. func is called each time data can be written to fd. A single write handler per file handle is supported. Use func = null to remove the handler.

os.setWriteHandler(fd, func);

sleep​

Sleep during delay_ms milliseconds.

os.sleep(delay_ms);

setTimeout​

Call the function func after delay ms. Return a handle to the timer.

os.setTimeout(func, delay);

setInterval​

Call the function func at specified intervals (in milliseconds). Return a handle to the timer.

os.setInterval(func, interval);

setImmediate​

Executes a given function immediately.

os.setImmediate(func);

clearTimeout​

Cancel a timer.

os.clearTimeout(handle);

clearInterval​

Cancel a interval.

os.clearInterval(handle);

clearImmediate​

Cancel a immediate execution.

os.clearImmediate(handle);