Some core modules, such as
process
and
buffer
, are global, are always available, and
do not require an explicit
require
statement. The core modules are listed in
Table 20-2. Core modules
Module
Global Description
assert
No
Used for testing purposes.
buffer
Yes
For input/output (I/O) operations (primarily file and network).
child_process
No
Functions for running external programs (Node and otherwise).
cluster
No
Allows you to take advantage of multiple processes for performance.
crypto
No
Built-in cryptography libraries.
dns
No
Domain name system (DNS) functions for network name resolution.
domain
No
Allows grouping of I/O and other asynchronous operations to isolate errors.
events
No
Utilities to support asynchronous events.
fs
No
Filesystem operations.
http
No
HTTP server and related utilities.
https
No
HTTPS server and related utilities.
net
No
Asynchronous socket-based network API.
os
No
Operating system utilities.
path
No
Filesystem pathname utilities.
punycode
No
Encoding of Unicode using a limited ASCII subset.
querystring
No
Utilities for parsing and constructing URL querystrings.
readline
No
Interactive I/O utilities; primarily used for command-line programs.
smalloc
No
Allows for explicit allocation of memory for buffers.
stream
Yes
Stream-based data transfer.
string_decoder
No
Converts buffers to strings.
Core Modules, File Modules, and npm Modules | 285
