node

Run a JavaScript file

$ node [path/to/file]

$ node

$ node --watch [path/to/file]

$ node -e "[code]"

$ node -p "process.versions"

$ node --no-lazy --inspect-brk [path/to/file]

ode [options] [v8-options] [-e string | script.js | -] [--] [arguments ...] node inspect [-e string | script.js | - | :] ... node [--v8-options]

Node.js is a set of libraries for JavaScript which allows it to be used outside of the browser. It is primarily focused on creating simple, easy-to-build network clients and servers. Execute node without arguments to start a REPL.

- Alias for stdin, analogous to the use of - in other command-line utilities. The executed script is read from stdin, and remaining arguments are passed to the script. -- Indicate the end of command-line options. Pass the rest of the arguments to the script. If no script filename or eval/print script is supplied prior to this, then the next argument will be used as a script filename. --abort-on-uncaught-exception Aborting instead of exiting causes a core file to be generated for analysis. --completion-bash Print source-able bash completion script for Node.js. --enable-fips Enable FIPS-compliant crypto at startup. Requires Node.js to be built with ./configure --openssl-fips. --experimental-modules Enable experimental ES module support and caching modules. --experimental-repl-await Enable experimental top-level await keyword support in REPL. --experimental-vm-modules Enable experimental ES module support in VM module. --experimental-worker Enable experimental worker threads using worker_threads module. --force-fips Force FIPS-compliant crypto on startup (Cannot be disabled from script code). Same requirements as --enable-fips. --icu-data-dir=file Specify ICU data load path. Overrides NODE_ICU_DATA. --inspect-brk=[host:]port Activate inspector on host:port and break at start of user script. --inspect-port=[host:]port Set the host:port to be used when the inspector is activated. --inspect=[host:]port Activate inspector on host:port. Default is 127.0.0.1:9229. V8 Inspector integration allows attaching Chrome DevTools and IDEs to Node.js instances for debugging and profiling. It uses the Chrome DevTools Protocol. --loader=file Specify the file as a custom loader, to load --experimental-modules. --max-http-header-size=size Specify the maximum size of HTTP headers in bytes. Defaults to 8KB. --napi-modules This option is a no-op. It is kept for compatibility. --no-deprecation Silence deprecation warnings. --no-force-async-hooks-checks Disable runtime checks for `async_hooks`. These will still be enabled dynamically when `async_hooks` is enabled. --no-warnings Silence all process warnings (including deprecations). --openssl-config=file Load an OpenSSL configuration file on startup. Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with ./configure --openssl-fips. --pending-deprecation Emit pending deprecation warnings. --preserve-symlinks Instructs the module loader to preserve symbolic links when re‐ solving and caching modules other than the main module. --preserve-symlinks-main Instructs the module loader to preserve symbolic links when re‐ solving and caching the main module. --prof Generate V8 profiler output. --prof-process Process V8 profiler output generated using the V8 option --prof. --redirect-warnings=file Write process warnings to the given file instead of printing to stderr. --throw-deprecation Throw errors for deprecations. --title=title Specify process.title on startup. --tls-cipher-list=list Specify an alternative default TLS cipher list. Requires Node.js to be built with crypto support. (Default) --trace-deprecation Print stack traces for deprecations. --trace-event-categories categories A comma-separated list of categories that should be traced when trace event tracing is enabled using --trace-events-enabled. --trace-event-file-pattern pattern Template string specifying the filepath for the trace event data, it supports ${rotation} and ${pid}. --trace-events-enabled Enable the collection of trace event tracing information. --trace-sync-io Print a stack trace whenever synchronous I/O is detected after the first turn of the event loop. --trace-warnings Print stack traces for process warnings (including deprecations). --track-heap-objects Track heap object allocations for heap snapshots. --use-bundled-ca, --use-openssl-ca Use bundled Mozilla CA store as supplied by current Node.js ver‐ sion or use OpenSSL's default CA store. The default store is se‐ lectable at build-time. The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store that is fixed at release time. It is identical on all supported platforms. Using OpenSSL store allows for external modifications of the store. For most Linux and BSD distributions, this store is main‐ tained by the distribution maintainers and system administrators. OpenSSL CA store location is dependent on configuration of the OpenSSL library but this can be altered at runtime using environ‐ ment variables. See SSL_CERT_DIR and SSL_CERT_FILE. --v8-options Print V8 command-line options. --v8-pool-size=num Set V8's thread pool size which will be used to allocate back‐ ground jobs. If set to 0 then V8 will choose an appropriate size of the thread pool based on the number of online processors. If the value provided is larger than V8's maximum, then the largest value will be chosen. --zero-fill-buffers Automatically zero-fills all newly allocated Buffer and Slow‐ Buffer instances. -c, --check Check the script's syntax without executing it. Exits with an error code if script is invalid. -e, --eval string Evaluate string as JavaScript. -h, --help Print command-line options. The output of this option is less detailed than this document. -i, --interactive Open the REPL even if stdin does not appear to be a terminal. -p, --print string Identical to -e, but prints the result. -r, --require module Preload the specified module at startup. Follows `require()`'s module resolution rules. module may be either a path to a file, or a Node.js module name. -v, --version Print node's version.

NODE_DEBUG modules... Comma-separated list of core modules that should print debug in‐ formation. NODE_DEBUG_NATIVE modules... Comma-separated list of C++ core modules that should print debug information. NODE_DISABLE_COLORS When set to 1, colors will not be used in the REPL. NODE_EXTRA_CA_CERTS file When set, the well-known “root” CAs (like VeriSign) will be ex‐ tended with the extra certificates in file. The file should con‐ sist of one or more trusted certificates in PEM format. If file is missing or misformatted, a message will be emitted once using process.emitWarning(), but any errors are otherwise ignored. This environment variable is ignored when `node` runs as setuid root or has Linux file capabilities set. NODE_ICU_DATA file Data path for ICU (Intl object) data. Will extend linked-in data when compiled with small-icu support. NODE_NO_WARNINGS When set to 1, process warnings are silenced. NODE_OPTIONS options... A space-separated list of command-line options, which are inter‐ preted as if they had been specified on the command-line before the actual command (so they can be overridden). Node.js will exit with an error if an option that is not allowed in the envi‐ ronment is used, such as --print or a script file. NODE_PATH directories... A colon-separated list of directories prefixed to the module search path. NODE_PENDING_DEPRECATION When set to 1, emit pending deprecation warnings. NODE_PRESERVE_SYMLINKS When set to 1, the module loader preserves symbolic links when resolving and caching modules. NODE_REDIRECT_WARNINGS file Write process warnings to the given file instead of printing to stderr. Equivalent to passing --redirect-warnings file on com‐ mand-line. NODE_REPL_HISTORY file Path to the file used to store persistent REPL history. The de‐ fault path is ~/.node_repl_history, which is overridden by this variable. Setting the value to an empty string ("" or " ") will disable persistent REPL history. NODE_TLS_REJECT_UNAUTHORIZED When set to 0, TLS certificate validation is disabled. NODE_V8_COVERAGE dir When set, Node.js writes JavaScript code coverage information to dir. OPENSSL_CONF file Load an OpenSSL configuration file on startup. Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with ./configure --openssl-fips. If the --openssl-config command-line option is used, this envi‐ ronment variable is ignored. SSL_CERT_DIR dir If --use-openssl-ca is enabled, this overrides and sets OpenSSL's directory containing trusted certificates. SSL_CERT_FILE file If --use-openssl-ca is enabled, this overrides and sets OpenSSL's file containing trusted certificates. UV_THREADPOOL_SIZE size Sets the number of threads used in libuv's threadpool to size.

Bugs are tracked in GitHub Issues: https://github.com/nodejs/node/issues

Copyright Node.js contributors. Node.js is available under the MIT li‐ cense. Node.js also includes external libraries that are available under a vari‐ ety of licenses. See https://github.com/nodejs/node/blob/master/LICENSE for the full license text.

Written and maintained by 1000+ contributors: https://github.com/nodejs/node/blob/master/AUTHORS September 17, 2019

Website: https://nodejs.org/ Documentation: https://nodejs.org/api/ GitHub repository & Issue Tracker: https://github.com/nodejs/node IRC (general questions): chat.freenode.net #node.js (unofficial) IRC (Node.js core development): chat.freenode.net #node-dev