node/doc/node.1

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.\"======================================================================
.
.tr -\-^\(ha~\(ti`\(ga
.Dd 2018
.Dt NODE 1
.
.Sh NAME
.Nm node
.Nd server-side JavaScript runtime
.
.\"======================================================================
.Sh SYNOPSIS
.Nm node
.Op Ar options
.Op Ar v8-options
.Op Fl e Ar string | Ar script.js | Fl
.Op Fl -
.Op Ar arguments ...
.
.Nm node
.Cm inspect
.Op Ar <program-entry-point> | Fl e Ar string | Ar <host>:<port>
.Ar ...
.
.Nm node
.Op Fl -v8-options
.
.\"======================================================================
.Sh DESCRIPTION
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.
.Pp
Execute
.Nm
without arguments to start a REPL.
.
.Sh OPTIONS
.Bl -tag -width 6n
.It Sy -
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.
.
.It Fl -
Indicate the end of command-line options.
Pass the rest of the arguments to the script.
.Pp
If no script filename or eval/print script is supplied prior to this, then
the next argument will be used as a script filename.
.
.It Fl -abort-on-uncaught-exception
Aborting instead of exiting causes a core file to be generated for analysis.
.
.It Fl -allow-fs-read
Allow file system read access when using the permission model.
.
.It Fl -allow-fs-write
Allow file system write access when using the permission model.
.
.It Fl -allow-addons
Allow using native addons when using the permission model.
.
.It Fl -allow-child-process
Allow spawning process when using the permission model.
.
.It Fl -allow-inspector
Allow inspector access when using the permission model.
.
.It Fl -allow-openssl-store
Allow using OpenSSL STORE loaders when using the permission model.
.
.It Fl -allow-wasi
Allow execution of WASI when using the permission model.
.
.It Fl -allow-worker
Allow creating worker threads when using the permission model.
.
.It Fl -completion-bash
Print source-able bash completion script for Node.js.
.
.It Fl C , Fl -conditions Ar string
Use custom conditional exports conditions.
.Ar string
.
.It Fl -cpu-prof
Start the V8 CPU profiler on start up, and write the CPU profile to disk
before exit. If
.Fl -cpu-prof-dir
is not specified, the profile will be written to the current working directory
with a generated file name.
.
.It Fl -cpu-prof-dir
The directory where the CPU profiles generated by
.Fl -cpu-prof
will be placed.
The default value is controlled by the
.Fl -diagnostic-dir .
command-line option.
.
.It Fl -cpu-prof-interval
The sampling interval in microseconds for the CPU profiles generated by
.Fl -cpu-prof .
The default is
.Sy 1000 .
.
.It Fl -cpu-prof-name
File name of the V8 CPU profile generated with
.Fl -cpu-prof .
.
.It Fl -diagnostic-dir
Set the directory for all diagnostic output files.
Default is current working directory.
Set the directory to which all diagnostic output files will be written to.
Defaults to current working directory.
.
Affects the default output directory of:
.Fl -cpu-prof-dir .
.Fl -heap-prof-dir .
.Fl -redirect-warnings .
.
.It Fl -disable-proto Ns = Ns Ar mode
Disable the `Object.prototype.__proto__` property. If
.Ar mode
is `delete`, the property will be removed entirely. If
.Ar mode
is `throw`, accesses to the property will throw an exception with the code
`ERR_PROTO_ACCESS`.
.
.It Fl -disable-wasm-trap-handler Ns = Ns Ar mode
Disable trap-handler-based WebAssembly bound checks and fall back to
inline bound checks so that WebAssembly can be run with limited virtual
memory.
.
.It Fl -disallow-code-generation-from-strings
Make built-in language features like `eval` and `new Function` that generate
code from strings throw an exception instead. This does not affect the Node.js
`vm` module.
.
.It Fl -enable-fips
Enable FIPS mode at startup. With OpenSSL 3, a configured provider named
\fBfips\fR must be available and initialize successfully. With OpenSSL 1.1.1,
Node.js must be built against a FIPS-capable OpenSSL.
.
.It Fl -enable-fips-indicator-events
Publish OpenSSL FIPS indicator results to the
\fB'crypto.fips.indicator'\fR diagnostics channel. This option requires OpenSSL
3.4 or later. It does not enable FIPS mode or change whether an operation
is permitted.
.
.It Fl -enable-source-maps
Enable Source Map V3 support for stack traces.
.
.It Fl -entry-url
Interpret the entry point as a URL.
.
.It Fl -experimental-addon-modules
Enable experimental addon module support.
.
.It Fl -experimental-config-file , Fl -experimental-config-file Ns = Ns Ar config , Fl -experimental-default-config-file
If present, Node.js will look for a configuration file at the specified path.
If the path is not specified, Node.js will look for a \fBnode.config.json\fR file
in the current working directory.
To specify a custom path, use the \fB--experimental-config-file=\fR\fBpath\fR form.
The space-separated \fB--experimental-config-file path\fR form is not supported.
Node.js will read the configuration file and apply the settings. The
configuration file should be a JSON file with the following structure. \fBvX.Y.Z\fR
in the \fB$schema\fR must be replaced with the version of Node.js you are using.
.Bd -literal
{
  "$schema": "https://nodejs.org/dist/vX.Y.Z/docs/node-config-schema.json",
  "nodeOptions": {
    "import": [
      "amaro/strip"
    ],
    "watch-path": "src",
    "watch-preserve-output": true
  },
  "testRunner": {
    "test-isolation": "process"
  },
  "watch": {
    "watch-preserve-output": true
  }
}
.Ed
The configuration file supports namespace-specific options:
.Bl -bullet
.It
The \fBnodeOptions\fR field contains CLI flags that are allowed in \fBNODE_OPTIONS\fR.
.It
Namespace fields like \fBtestRunner\fR contain configuration specific to that subsystem.
.El
No-op flags are not supported.
Not all V8 flags are currently supported.
It is possible to use the official JSON schema
to validate the configuration file, which may vary depending on the Node.js version.
Each key in the configuration file corresponds to a flag that can be passed
as a command-line argument. The value of the key is the value that would be
passed to the flag.
For example, the configuration file above is equivalent to
the following command-line arguments:
.Bd -literal
node --import amaro/strip --watch-path=src --watch-preserve-output --test-isolation=process
.Ed
The priority in configuration is as follows:
.Bl -bullet
.It
NODE_OPTIONS and command-line options
.It
Dotenv NODE_OPTIONS
.It
Configuration file
.El
Values in the configuration file will not override the values in the environment
variables, command-line options, or the \fBNODE_OPTIONS\fR env file parsed by the
\fB--env-file\fR flag.
Keys cannot be duplicated within the same or different namespaces.
The configuration parser will throw an error if the configuration file contains
unknown keys or keys that cannot be used in a namespace.
Node.js will not sanitize or perform validation on the user-provided configuration,
so \fBNEVER\fR use untrusted configuration files.
.
.It Fl -experimental-default-config-file
This flag is an alias for \fB--experimental-config-file\fR without an argument.
If present, Node.js will look for a
\fBnode.config.json\fR file in the current working directory and load it as a
configuration file.
.
.It Fl -experimental-import-meta-resolve
Enable experimental ES modules support for import.meta.resolve().
.
.It Fl -experimental-import-text
Enable experimental support for importing modules with \fBwith { type: 'text' }\fR.
.
.It Fl -experimental-loader Ns = Ns Ar module
Specify the
.Ar module
to use as a custom module loader.
.
.It Fl -permission
Enable the permission model.
.
.It Fl -experimental-package-map Ns = Ns Ar path
Enable experimental package map resolution using the specified configuration file.
.
.It Fl -experimental-stream-iter
Enable the experimental
.Sy node:stream/iter
module.
.
.It Fl -experimental-shadow-realm
Use this flag to enable ShadowRealm support.
.
.It Fl -experimental-test-coverage
Enable code coverage in the test runner.
.
.It Fl -experimental-test-module-mocks
Enable module mocking in the test runner.
.
.It Fl -experimental-transform-types
Enable transformation of TypeScript-only syntax into JavaScript code.
.
.It Fl -experimental-eventsource
Enable experimental support for the EventSource Web API.
.
.It Fl -no-experimental-websocket
Disable experimental support for the WebSocket API.
.
.It Fl -experimental-webstorage
Enable experimental support for the Web Storage API.
.
.It Fl -no-experimental-repl-await
Disable top-level await keyword support in REPL.
.
.It Fl -no-experimental-sqlite
Disable the experimental node:sqlite module.
.
.It Fl -no-require-module
Disable support for loading ECMAScript modules with require().
.
.It Fl -no-strip-types
Disable type-stripping for TypeScript files.
.
.It Fl -experimental-test-tag-filter Ar tag
Run only tests whose tag set contains \fItag\fR. May be specified multiple
times; tests must contain every filter to run.
.
.It Fl -experimental-vm-modules
Enable experimental ES module support in VM module.
.
.It Fl -experimental-wasi-unstable-preview1
Enable experimental WebAssembly System Interface support. This
flag is no longer required as WASI is enabled by default.
.
.It Fl -experimental-quic
Enable the experimental QUIC support.
.
.It Fl -experimental-inspector-network-resource
Enable experimental support for inspector network resources.

.It Fl -experimental-storage-inspection
Enable experimental support for storage inspection.

.
.It Fl -force-context-aware
Disable loading native addons that are not context-aware.
.
.It Fl -force-fips Ns = Ns Ar [mode]
Enable FIPS mode at startup and prevent it from being disabled from script
code. The same OpenSSL requirements as \fB--enable-fips\fR apply.
An optional mode can be specified using \fB--force-fips=mode\fR:
.Bl -bullet
.It
\fBprovider\fR: Preserve the OpenSSL FIPS provider's configured handling of
non-approved operations. This is the current default when the mode is
omitted.
.It
\fBstrict\fR: Reject non-approved operations reported through the OpenSSL FIPS
indicator callback. This mode requires OpenSSL 3.4 or later.
.El
The \fBstrict\fR mode only covers operations reported through the callback for
OpenSSL's default library context. It does not cover native addons that use
another \fBOSSL_LIB_CTX\fR or another copy of \fBlibcrypto\fR, nor operation-specific
indicators that do not invoke the callback.
.
.It Fl -frozen-intrinsics
Enable experimental frozen intrinsics support.
.
.It Fl -heapsnapshot-near-heap-limit Ns = Ns Ar max_count
Generate heap snapshot when the V8 heap usage is approaching the heap limit.
No more than the specified number of snapshots will be generated.
.
.It Fl -heapsnapshot-signal Ns = Ns Ar signal
Generate heap snapshot on specified signal.
.
.It Fl -heap-prof
Start the V8 heap profiler on start up, and write the heap profile to disk
before exit. If
.Fl -heap-prof-dir
is not specified, the profile will be written to the current working directory
with a generated file name.
.
.It Fl -heap-prof-dir
The directory where the heap profiles generated by
.Fl -heap-prof
will be placed.
The default value is controlled by the
.Fl -diagnostic-dir .
command-line option.
.
.It Fl -heap-prof-interval
The average sampling interval in bytes for the heap profiles generated by
.Fl -heap-prof .
The default is
.Sy 512 * 1024 .
.
.It Fl -heap-prof-name
File name of the V8 heap profile generated with
.Fl -heap-prof .
.
.It Fl -icu-data-dir Ns = Ns Ar file
Specify ICU data load path.
Overrides
.Ev NODE_ICU_DATA .
.
.It Fl -input-type Ns = Ns Ar type
Set the module resolution type for input via --eval, --print or STDIN.
.
.It Fl -inspect-brk Ns = Ns Ar [host:]port
Activate inspector on
.Ar host:port
and break at start of user script.
.
.It Fl -inspect-port Ns = Ns Ar [host:]port
Set the
.Ar host:port
to be used when the inspector is activated.
.
.It Fl -inspect-publish-uid=stderr,http
Specify how the inspector WebSocket URL is exposed.
Valid values are
.Sy stderr
and
.Sy http .
Default is
.Sy stderr,http .
.
.It Fl -inspect-wait Ns = Ns Ar [host:]port
Activate inspector on
.Ar host:port
and wait for debugger to be attached.
.
.It Fl -inspect Ns = Ns Ar [host:]port
Activate inspector on
.Ar host:port .
Default is
.Sy 127.0.0.1:9229 .
.Pp
V8 Inspector integration allows attaching Chrome DevTools and IDEs to Node.js instances for debugging and profiling.
It uses the Chrome DevTools Protocol.
.
.It Fl -insecure-http-parser
Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow
interoperability with non-conformant HTTP implementations. It may also allow
request smuggling and other HTTP attacks that rely on invalid headers being
accepted. Avoid using this option.
.
.It Fl -jitless
Disable runtime allocation of executable memory. This may be required on
some platforms for security reasons. It can also reduce attack surface on
other platforms, but the performance impact may be severe.
.
.Pp
This flag is inherited from V8 and is subject to change upstream. It may
disappear in a non-semver-major release.
.
.It Fl -localstorage-file Ns = Ns Ar file
The file used to store localStorage data.
.
.It Fl -max-http-header-size Ns = Ns Ar size
Specify the maximum size of HTTP headers in bytes. Defaults to 16 KiB.
.
.It Fl -max-old-space-size-percentage Ns = Ns Ar percentage
Sets the maximum memory size of V8's old memory section as a percentage of available system memory.
This flag takes precedence over
.Fl -max-old-space-size
when both are specified.
The
.Ar percentage
parameter must be a number greater than 0 and up to 100, representing the percentage
of available system memory to allocate to the V8 heap.
.Pp
Note: This flag utilizes
.Fl -max-old-space-size ,
which may be unreliable on 32-bit platforms due to integer overflow issues.
.
.It Fl -no-deprecation
Silence deprecation warnings.
.
.It Fl -no-extra-info-on-fatal-exception
Hide extra information on fatal exception that causes exit.
.
.It Fl -no-force-async-hooks-checks
Disable runtime checks for `async_hooks`.
These will still be enabled dynamically when `async_hooks` is enabled.
.
.It Fl -no-addons
Disable the `node-addons` exports condition as well as disable loading native
addons. When `--no-addons` is specified, calling `process.dlopen` or requiring
a native C++ addon will fail and throw an exception.
.
.It Fl -no-global-search-paths
Do not search modules from global paths.
.
.It Fl -no-warnings
Silence all process warnings (including deprecations).
.
.It Fl -node-memory-debug
Enable extra debug checks for memory leaks in Node.js internals. This is
usually only useful for developers debugging Node.js itself.
.
.It Fl -openssl-config Ns = Ns Ar file
Load an OpenSSL configuration file on startup. The file can activate an
OpenSSL 3 FIPS provider or configure a FIPS-capable OpenSSL 1.1.1 build. See
FIPS mode.
This option takes precedence over the \fBOPENSSL_CONF\fR environment variable.
.
.It Fl -openssl-legacy-provider
Enable OpenSSL 3.0 legacy provider. For more information please see
OSSL_PROVIDER-legacy.
.
.It Fl -openssl-shared-config
Enable OpenSSL default configuration section, \fBopenssl_conf\fR to be read from
the OpenSSL configuration file. The default configuration file is named
\fBopenssl.cnf\fR but this can be changed using the environment variable
\fBOPENSSL_CONF\fR, or by using the command line option \fB--openssl-config\fR.
The location of the default OpenSSL configuration file depends on how OpenSSL
is being linked to Node.js. Sharing the OpenSSL configuration may have unwanted
implications and it is recommended to use a configuration section specific to
Node.js which is \fBnodejs_conf\fR and is default when this option is not used.
.
.It Fl -pending-deprecation
Emit pending deprecation warnings.
.
.It Fl -permission-audit
Enable audit mode for the permission model. When enabled, permission checks
are performed but access is \fBnot\fR denied — no \fBERR_ACCESS_DENIED\fR error is
thrown. Instead, each permission violation is published through the
\fBnode:diagnostics_channel\fR module, and execution continues normally.
This flag does not require \fB--permission\fR to be specified. The
\fB--allow-*\fR flags are not needed in audit mode, since no
access is denied.
Audit mode is useful for discovering what permissions your application
requires before deploying with \fB--permission\fR. See the
Permission Model documentation for the list of diagnostics channel names
and the message format.
If both \fB--permission\fR and \fB--permission-audit\fR are specified,
\fB--permission\fR takes precedence and the Permission Model runs in enforce mode.
.
.It Fl -preserve-symlinks
Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
.
.It Fl -preserve-symlinks-main
Instructs the module loader to preserve symbolic links when resolving and caching the main module.
.
.It Fl -prof
Generate V8 profiler output.
.
.It Fl -prof-process
Process V8 profiler output generated using the V8 option
.Fl -prof .
.
.It Fl -redirect-warnings Ns = Ns Ar file
Write process warnings to the given
.Ar file
instead of printing to stderr.
.
.It Fl -report-compact
Write
.Sy diagnostic reports
in a compact format, single-line JSON.
.
.It Fl -report-dir Fl -report-directory
Location at which the
.Sy diagnostic report
will be generated.
The `file` name may be an absolute path. If it is not, the default directory it will
be written to is controlled by the
.Fl -diagnostic-dir .
command-line option.
.
.It Fl -report-filename
Name of the file to which the
.Sy diagnostic report
will be written.
.
.It Fl -report-on-fatalerror
Enables the
.Sy diagnostic report
to be triggered on fatal errors (internal errors within the Node.js runtime such
as out of memory) that leads to termination of the application. Useful to
inspect various diagnostic data elements such as heap, stack, event loop state,
resource consumption etc. to reason about the fatal error.
.
.It Fl -report-on-signal
Enables
.Sy diagnostic report
to be generated upon receiving the specified (or predefined) signal to the
running Node.js process. Default signal is SIGUSR2.
.
.It Fl -report-signal
Sets or resets the signal for
.Sy diagnostic report
generation (not supported on Windows). Default signal is SIGUSR2.
.
.It Fl -report-uncaught-exception
Enables
.Sy diagnostic report
to be generated on un-caught exceptions. Useful when inspecting JavaScript
stack in conjunction with native stack and other runtime environment data.
.
.It Fl -secure-heap Ns = Ns Ar n
Specify the size of the OpenSSL secure heap. Any value less than 2 disables
the secure heap. The default is 0. The value must be a power of two.
.
.It Fl -secure-heap-min Ns = Ns Ar n
Specify the minimum allocation from the OpenSSL secure heap. The default is 2. The value must be a power of two.
.
.It Fl -test
Starts the Node.js command line test runner.
.
.It Fl -test-concurrency
The maximum number of test files that the test runner CLI will execute
concurrently.
.
.It Fl -test-coverage-branches Ns = Ns Ar threshold
Require a minimum threshold for branch coverage (0 - 100).
.
.It Fl -test-coverage-exclude
A glob pattern that excludes matching files from the coverage report
.
.It Fl -test-coverage-functions Ns = Ns Ar threshold
Require a minimum threshold for function coverage (0 - 100).
.
.It Fl -test-coverage-include
A glob pattern that only includes matching files in the coverage report
.
.It Fl -test-coverage-lines Ns = Ns Ar threshold
Require a minimum threshold for line coverage (0 - 100).
.
.It Fl -test-force-exit
Configures the test runner to exit the process once all known tests have
finished executing even if the event loop would otherwise remain active.
.
.It Fl -test-global-setup
Specifies a module containing global setup and teardown functions for the test runner.
.
.It Fl -test-isolation Ns = Ns Ar mode
Configures the type of test isolation used in the test runner.
.
.It Fl -test-name-pattern
A regular expression that configures the test runner to only execute tests
whose name matches the provided pattern.
.
.It Fl -test-random-seed
Set the seed used to randomize test execution order.
This applies to both test file execution order and queued tests within each file.
Providing this flag enables randomization implicitly, even without
\fB--test-randomize\fR.
The value must be an integer between 0 and 4294967295.
This flag cannot be used with \fB--watch\fR or \fB--test-rerun-failures\fR.
.
.It Fl -test-randomize
Randomize test execution order.
This applies to both test file execution order and queued tests within each file.
This can help detect tests that rely on shared state or execution order.
The seed used for randomization is printed in the test summary and can be
reused with \fB--test-random-seed\fR.
This flag cannot be used with \fB--watch\fR or \fB--test-rerun-failures\fR.
.
.It Fl -test-reporter
A test reporter to use when running tests.
.
.It Fl -test-reporter-destination
The destination for the corresponding test reporter.
.
.It Fl -test-rerun-failures
Configures the tests runner to persist the state of tests to allow
rerunning only failed tests.
.
.It Fl -test-only
Configures the test runner to only execute top level tests that have the `only`
option set.
.
.It Fl -test-shard
Test suite shard to execute in a format of <index>/<total>.
.
.It Fl -test-skip-pattern
A regular expression that configures the test runner to skip tests
whose name matches the provided pattern.
.
.It Fl -test-timeout
A number of milliseconds the test execution will fail after.
.
.It Fl -test-update-snapshots
Regenerates the snapshot file used by the test runner for snapshot testing.
.
.It Fl -throw-deprecation
Throw errors for deprecations.
.
.It Fl -title Ns = Ns Ar title
Specify process.title on startup.
.
.It Fl -tls-cipher-list Ns = Ns Ar list
Specify an alternative default TLS cipher list.
Requires Node.js to be built with crypto support. (Default)
.
.It Fl -tls-keylog Ns = Ns Ar file
Log TLS key material to a file. The key material is in NSS SSLKEYLOGFILE
format and can be used by software (such as Wireshark) to decrypt the TLS
traffic.
.
.It Fl -tls-max-v1.2
Set default  maxVersion to 'TLSv1.2'. Use to disable support for TLSv1.3.
.
.It Fl -tls-max-v1.3
Set default  maxVersion to 'TLSv1.3'. Use to enable support for TLSv1.3.
.
.It Fl -tls-min-v1.0
Set default minVersion to 'TLSv1'. Use for compatibility with old TLS clients
or servers.
.
.It Fl -tls-min-v1.1
Set default minVersion to 'TLSv1.1'. Use for compatibility with old TLS clients
or servers.
.
.It Fl -tls-min-v1.2
Set default minVersion to 'TLSv1.2'. This is the default for 12.x and later,
but the option is supported for compatibility with older Node.js versions.
.
.It Fl -tls-min-v1.3
Set default minVersion to 'TLSv1.3'. Use to disable support for TLSv1.2 in
favour of TLSv1.3, which is more secure.
.
.It Fl -trace-deprecation
Print stack traces for deprecations.
.
.It Fl -trace-event-categories Ar categories
A comma-separated list of categories that should be traced when trace event tracing is enabled using
.Fl -trace-events-enabled .
.
.It Fl -trace-event-file-pattern Ar pattern
Template string specifying the filepath for the trace event data, it
supports
.Sy ${rotation}
and
.Sy ${pid} .
.
.It Fl -trace-events-enabled
Enable the collection of trace event tracing information.
.
.It Fl -trace-exit
Prints a stack trace whenever an environment is exited proactively,
i.e. invoking `process.exit()`.
.It Fl -trace-sigint
Prints a stack trace on SIGINT.
.
.It Fl -trace-sync-io
Print a stack trace whenever synchronous I/O is detected after the first turn of the event loop.
.
.It Fl -trace-tls
Prints TLS packet trace information to stderr.
.
.It Fl -trace-uncaught
Print stack traces for uncaught exceptions; usually, the stack trace associated
with the creation of an
.Sy Error
is printed, whereas this makes Node.js also
print the stack trace associated with throwing the value (which does not need
to be an
.Sy Error
instance).
.Pp
Enabling this option may affect garbage collection behavior negatively.
.
.It Fl -trace-warnings
Print stack traces for process warnings (including deprecations).
.
.It Fl -track-heap-objects
Track heap object allocations for heap snapshots.
.
.It Fl -unhandled-rejections=mode
Define the behavior for unhandled rejections. Can be one of `strict` (raise an error), `warn` (enforce warnings) or `none` (silence warnings).
.
.It Fl -use-bundled-ca , Fl -use-openssl-ca
Use bundled Mozilla CA store as supplied by current Node.js version or use OpenSSL's default CA store.
The default store is selectable at build-time.
.Pp
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.
.Pp
Using OpenSSL store allows for external modifications of the store.
For most Linux and BSD distributions, this store is maintained 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 environment variables.
.Pp
See
.Ev SSL_CERT_DIR
and
.Ev SSL_CERT_FILE .
.
.It Fl -use-env-proxy
Parse proxy settings from HTTP_PROXY/HTTPS_PROXY/NO_PROXY environment variables and apply the setting in global HTTP/HTTPS clients.
.
.It Fl -use-system-ca
Use the trusted CA certificates present in the system store, in addition to the certificates in the
bundled Mozilla CA store and certificates from `NODE_EXTRA_CA_CERTS`. On Windows and macOS, it uses system APIs to
integrate additional trusted certificates. On other platforms it is similar to `--use-openssl-ca` with the difference
being that it caches the certificates on first load, and the system certificates are added in a complementary manner
without replacing certificates from other sources. This flag supersedes `--use-openssl-ca`.
.
.It Fl -use-largepages Ns = Ns Ar mode
Re-map the Node.js static code to large memory pages at startup. If supported on
the target system, this will cause the Node.js static code to be moved onto 2
MiB pages instead of 4 KiB pages.
.Pp
.Ar mode
must have one of the following values:
`off` (the default value, meaning do not map), `on` (map and ignore failure,
reporting it to stderr), or `silent` (map and silently ignore failure).
.
.It Fl -v8-options
Print V8 command-line options.
.
.It Fl -v8-pool-size Ns = Ns Ar num
Set V8's thread pool size which will be used to allocate background 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.
.
.It Fl -watch
Starts Node.js in watch mode. When in watch mode, changes in the watched files cause the Node.js process to restart.

By default, watch mode will watch the entry point and any required or imported module. Use --watch-path to specify what paths to watch.
.
.It Fl -watch-path
Starts Node.js in watch mode and specifies what paths to watch. When in watch mode, changes in the watched paths cause the Node.js process to restart.

This will turn off watching of required or imported modules, even when used in combination with --watch.
.
.It Fl -watch-kill-signal
Customizes the signal sent to the process on watch mode restarts.
.
.It Fl -zero-fill-buffers
Automatically zero-fills all newly allocated Buffer and SlowBuffer instances.
.
.It Fl c , Fl -check
Check the script's syntax without executing it.
Exits with an error code if script is invalid.
.
.It Fl e , Fl -eval Ar string
Evaluate
.Ar string
as JavaScript.
.
.It Fl h , Fl -help
Print command-line options.
The output of this option is less detailed than this document.
.
.It Fl i , Fl -interactive
Open the REPL even if stdin does not appear to be a terminal.
.
.It Fl p , Fl -print Ar string
Identical to
.Fl e ,
but prints the result.
.
.It Fl r , Fl -require Ar module
Preload the specified
.Ar module
at startup.
Follows `require()`'s module resolution rules.
.Ar module
may be either a path to a file, or a Node.js module name.
.
.It Fl v , Fl -version
Print node's version.
.El
.
.\" =====================================================================
.Sh ENVIRONMENT
.Bl -tag -width 6n
.It Ev FORCE_COLOR
Used to enable ANSI colorized output. The value may be one of:
.Ar 1
,
.Ar true
, or
.Ar an empty string
to
indicate 16-color support,
.Ar 2
to indicate 256-color support, or
.Ar 3
to indicate 16 million-color support. When used and set to a supported
value, both the NO_COLOR and NODE_DISABLE_COLORS environment variables
are ignored. Any other value will result in colorized output being
disabled.
.
.It Ev NO_COLOR
Alias for NODE_DISABLE_COLORS
.
.It Ev NODE_COMPILE_CACHE Ar dir
Enable the
.Sy module compile cache
for the Node.js instance.
.
.It Ev NODE_COMPILE_CACHE_PORTABLE
When set to '1' or 'true', the
.Sy module compile cache
will be hit as long as the location of the modules relative to the cache directory remain
consistent. This can be used in conjunction with .Ev NODE_COMPILE_CACHE
to enable portable on-disk caching.
.
.It Ev NODE_DEBUG Ar modules...
Comma-separated list of core modules that should print debug information.
.
.It Ev NODE_DEBUG_NATIVE Ar modules...
Comma-separated list of C++ core modules that should print debug information.
.
.It Ev NODE_DISABLE_COMPILE_CACHE
Disable the
.Sy module compile cache
for the Node.js instance.
.
.It Ev NODE_DISABLE_COLORS
When set to
.Ar 1 ,
colors will not be used in the REPL.
.
.It Ev NODE_EXTRA_CA_CERTS Ar file
When set, the well-known
.Dq root
CAs (like VeriSign) will be extended with the extra certificates in
.Ar file .
The file should consist of one or more trusted certificates in PEM format.
.Pp
If
.Ar file
is missing or misformatted, a message will be emitted once using
.Sy process.emitWarning() ,
but any errors are otherwise ignored.
.Pp
This environment variable is ignored when `node` runs as setuid root or
has Linux file capabilities set.
.Pp
The
.Ar NODE_EXTRA_CA_CERTS
environment variable is only read when the Node.js process is first launched.
Changing the value at runtime using
.Ar process.env.NODE_EXTRA_CA_CERTS
has no effect on the current process.
.
.It Ev NODE_ICU_DATA Ar file
Data path for ICU (Intl object) data.
Will extend linked-in data when compiled with small-icu support.
.
.It Ev NODE_NO_WARNINGS
When set to
.Ar 1 ,
process warnings are silenced.
.
.It Ev NODE_OPTIONS Ar options...
A space-separated list of command-line
.Ar options ,
which are interpreted 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 environment is used, such as
.Fl -print
or a script file.
.
.It Ev NODE_PATH Ar directories...
A colon-separated list of
.Ar directories
prefixed to the module search path.
.
.It Ev NODE_PENDING_DEPRECATION
When set to
.Ar 1 ,
emit pending deprecation warnings.
.
.It Ev NODE_PENDING_PIPE_INSTANCES
Set the number of pending pipe instance handles when the pipe server is waiting for connections. This setting applies to Windows only.
.
.It Ev NODE_PRESERVE_SYMLINKS
When set to
.Ar 1 ,
the module loader preserves symbolic links when resolving and caching modules.
.
.It Ev NODE_REDIRECT_WARNINGS Ar file
Write process warnings to the given
.Ar file
instead of printing to stderr.
Equivalent to passing
.Fl -redirect-warnings Ar file
on the command line.
.
.It Ev NODE_REPL_HISTORY Ar file
Path to the
.Ar file
used to store persistent REPL history.
The default path is
.Sy ~/.node_repl_history ,
which is overridden by this variable.
Setting the value to an empty string ("" or " ") will disable persistent REPL history.
.
.It Ev NODE_REPL_EXTERNAL_MODULE Ar file
Path to a Node.js module which will be loaded in place of the built-in REPL.
Overriding this value to an empty string (`''`) will use the built-in REPL.
.
.It Ev NODE_SKIP_PLATFORM_CHECK
When set to
.Ar 1 ,
the check for a supported platform is skipped during Node.js startup.
Node.js might not execute correctly.
Any issues encountered on unsupported platforms will not be fixed.
.
.It Ev NODE_TEST_CONTEXT
When set to
.Ar 'child'
, test reporter options will be overridden and test output will be sent to stdout in the TAP format.
If any other value is provided, Node.js makes no guarantees about the reporter format used or its stability.
.
.It Ev NODE_TLS_REJECT_UNAUTHORIZED
When set to
.Ar 0 ,
TLS certificate validation is disabled.
.
.It Ev NODE_USE_ENV_PROXY
When enabled, Node.js parses the
.Ar HTTP_PROXY
,
.Ar HTTPS_PROXY
and
.Ar NO_PROXY
environment variables during startup, and tunnels requests over the specified proxy.
.Pp
This currently only affects requests sent over
.Ar fetch() .
Support for other built-in http and https methods is under way.
.
.It Ev NODE_USE_SYSTEM_CA
Similar to
.Fl -use-system-ca .
Use the trusted CA certificates present in the system store, in addition to the certificates in the
bundled Mozilla CA store and certificates from `NODE_EXTRA_CA_CERTS`.
.
.It Ev NODE_V8_COVERAGE Ar dir
When set, Node.js writes JavaScript code coverage information to
.Ar dir .
.
.It Ev OPENSSL_CONF Ar file
Load an OpenSSL configuration file on startup. The file can be used as part of
a FIPS mode configuration.
If the variable is set to an empty value, Node.js starts without loading any
OpenSSL configuration file. This is a way past a default configuration file
that exists but cannot be read, for example when \fB/etc/ssl\fR is not accessible
to the user Node.js runs as, which is otherwise fatal at startup. No
configuration is applied in that case, including any FIPS mode setup the
file would have performed.
If the \fB--openssl-config\fR command-line option is used, the environment
variable is ignored, and an empty value has no effect.
.
.It Ev SSL_CERT_DIR Ar dir
If
.Fl -use-openssl-ca
is enabled, this overrides and sets OpenSSL's directory containing trusted certificates.
.
.It Ev SSL_CERT_FILE Ar file
If
.Fl -use-openssl-ca
is enabled, this overrides and sets OpenSSL's file containing trusted certificates.
.
.It Ev TZ
Specify the timezone configuration.
.
.It Ev UV_THREADPOOL_SIZE Ar size
Sets the number of threads used in libuv's threadpool to
.Ar size .
.
.El
.\"=====================================================================
.Sh BUGS
Bugs are tracked in GitHub Issues:
.Sy https://github.com/nodejs/node/issues
.
.\"======================================================================
.Sh COPYRIGHT
Copyright Node.js contributors.
Node.js is available under the MIT license.
.
.Pp
Node.js also includes external libraries that are available under a variety of licenses.
See
.Sy https://github.com/nodejs/node/blob/HEAD/LICENSE
for the full license text.
.
.\"======================================================================
.Sh SEE ALSO
Website:
.Sy https://nodejs.org/
.
.Pp
Documentation:
.Sy https://nodejs.org/api/
.
.Pp
GitHub repository and issue tracker:
.Sy https://github.com/nodejs/node