Node.js

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# Command Line Options#

Node.js comes with a variety of CLI options. These options expose built-in debugging, multiple ways to execute scripts, and other helpful runtime options.

To view this documentation as a manual page in your terminal, run `man node`.

## Synopsis#

`node [options] [v8 options] [script.js | -e "script"] [arguments]`

`node debug [script.js | -e "script" | <host>:<port>] …`

`node --v8-options`

Execute without arguments to start the REPL.

For more info about `node debug`, please see the debugger documentation.

## Options#

### `-v`, `--version`#

Added in: v0.1.3

Print node's version.

### `-h`, `--help`#

Added in: v0.1.3

Print node command line options. The output of this option is less detailed than this document.

### `-e`, `--eval "script"`#

Added in: v0.5.2

Evaluate the following argument as JavaScript.

### `-p`, `--print "script"`#

Added in: v0.6.4

Identical to `-e` but prints the result.

### `-c`, `--check`#

Added in: v4.2.0

Syntax check the script without executing.

### `-i`, `--interactive`#

Added in: v0.7.7

Opens the REPL even if stdin does not appear to be a terminal.

### `-r`, `--require module`#

Added in: v1.6.0

Preload the specified module at startup.

Follows `require()`'s module resolution rules. `module` may be either a path to a file, or a node module name.

### `--no-deprecation`#

Added in: v0.8.0

Silence deprecation warnings.

### `--trace-deprecation`#

Added in: v0.8.0

Print stack traces for deprecations.

### `--throw-deprecation`#

Added in: v0.11.14

Throw errors for deprecations.

### `--trace-sync-io`#

Added in: v2.1.0

Prints a stack trace whenever synchronous I/O is detected after the first turn of the event loop.

### `--zero-fill-buffers`#

Added in: v4.5.0

Automatically zero-fills all newly allocated Buffer and SlowBuffer instances.

### `--track-heap-objects`#

Added in: v2.4.0

Track heap object allocations for heap snapshots.

### `--prof-process`#

Added in: v4.4.0

Process v8 profiler output generated using the v8 option `--prof`.

### `--v8-options`#

Added in: v0.1.3

Print v8 command line options.

### `--tls-cipher-list=list`#

Added in: v4.0.0

Specify an alternative default TLS cipher list. (Requires Node.js to be built with crypto support. (Default))

### `--enable-fips`#

Enable FIPS-compliant crypto at startup. (Requires Node.js to be built with `./configure --openssl-fips`)

### `--force-fips`#

Force FIPS-compliant crypto on startup. (Cannot be disabled from script code.) (Same requirements as `--enable-fips`)

### `--icu-data-dir=file`#

Added in: v0.11.15

Specify ICU data load path. (overrides `NODE_ICU_DATA`)

## Environment Variables#

### `NODE_DEBUG=module[,…]`#

Added in: v0.1.32

`','`-separated list of core modules that should print debug information.

### `NODE_PATH=path[:…]`#

Added in: v0.1.32

`':'`-separated list of directories prefixed to the module search path.

Note: on Windows, this is a `';'`-separated list instead.

### `NODE_DISABLE_COLORS=1`#

Added in: v0.3.0

When set to `1` colors will not be used in the REPL.

### `NODE_ICU_DATA=file`#

Added in: v0.11.15

Data path for ICU (Intl object) data. Will extend linked-in data when compiled with small-icu support.

### `NODE_REPL_HISTORY=file`#

Added in: v3.0.0

Path to the file used to store the persistent REPL history. The default path is `~/.node_repl_history`, which is overridden by this variable. Setting the value to an empty string (`""` or `" "`) disables persistent REPL history.

### `NODE_EXTRA_CA_CERTS=file`#

Added in: XXX

When set, the well known "root" CAs (like VeriSign) will be extended with the extra certificates in `file`. The file should consist of one or more trusted certificates in PEM format. A message will be printed to stderr (once) if the file is missing or misformatted, but any errors are otherwise ignored.

Note that neither the well known nor extra certificates are used when the `ca` options property is explicitly specified for a TLS or HTTPS client or server.