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27.\"======================================================================
28.
29.Dd 2018
30.Dt NODE 1
31.
32.Sh NAME
33.Nm node
34.Nd server-side JavaScript runtime
35.
36.\"======================================================================
37.Sh SYNOPSIS
38.Nm node
39.Op Ar options
40.Op Ar v8-options
41.Op Fl e Ar string | Ar script.js | Fl
42.Op Fl -
43.Op Ar arguments ...
44.
45.Nm node
46.Cm inspect
47.Op Fl e Ar string | Ar script.js | Fl | Ar <host>:<port>
48.Ar ...
49.
50.Nm node
51.Op Fl -v8-options
52.
53.\"======================================================================
54.Sh DESCRIPTION
55Node.js is a set of libraries for JavaScript which allows it to be used outside of the browser.
56It is primarily focused on creating simple, easy-to-build network clients and servers.
57.Pp
58Execute
59.Nm
60without arguments to start a REPL.
61.
62.Sh OPTIONS
63.Bl -tag -width 6n
64.It Sy -
65Alias for stdin, analogous to the use of - in other command-line utilities.
66The executed script is read from stdin, and remaining arguments are passed to the script.
67.
68.It Fl -
69Indicate the end of command-line options.
70Pass the rest of the arguments to the script.
71.Pp
72If no script filename or eval/print script is supplied prior to this, then
73the next argument will be used as a script filename.
74.
75.It Fl -abort-on-uncaught-exception
76Aborting instead of exiting causes a core file to be generated for analysis.
77.
78.It Fl -completion-bash
79Print source-able bash completion script for Node.js.
80.
81.It Fl C , Fl -conditions Ar string
82Use custom conditional exports conditions.
83.Ar string
84.
85.It Fl -cpu-prof
86Start the V8 CPU profiler on start up, and write the CPU profile to disk
87before exit. If
88.Fl -cpu-prof-dir
89is not specified, the profile will be written to the current working directory
90with a generated file name.
91.
92.It Fl -cpu-prof-dir
93The directory where the CPU profiles generated by
94.Fl -cpu-prof
95will be placed.
96The default value is controlled by the
97.Fl -diagnostic-dir .
98command-line option.
99.
100.It Fl -cpu-prof-interval
101The sampling interval in microseconds for the CPU profiles generated by
102.Fl -cpu-prof .
103The default is
104.Sy 1000 .
105.
106.It Fl -cpu-prof-name
107File name of the V8 CPU profile generated with
108.Fl -cpu-prof .
109.
110.It Fl -diagnostic-dir
111Set the directory for all diagnostic output files.
112Default is current working directory.
113Set the directory to which all diagnostic output files will be written to.
114Defaults to current working directory.
115.
116Affects the default output directory of:
117.Fl -cpu-prof-dir .
118.Fl -heap-prof-dir .
119.Fl -redirect-warnings .
120.
121.It Fl -disable-proto Ns = Ns Ar mode
122Disable the `Object.prototype.__proto__` property. If
123.Ar mode
124is `delete`, the property will be removed entirely. If
125.Ar mode
126is `throw`, accesses to the property will throw an exception with the code
127`ERR_PROTO_ACCESS`.
128.
129.It Fl -disallow-code-generation-from-strings
130Make built-in language features like `eval` and `new Function` that generate
131code from strings throw an exception instead. This does not affect the Node.js
132`vm` module.
133.
134.It Fl -enable-fips
135Enable FIPS-compliant crypto at startup.
136Requires Node.js to be built with
137.Sy ./configure --openssl-fips .
138.
139.It Fl -experimental-abortcontroller
140Enable experimental AbortController and AbortSignal support.
141.
142.It Fl -enable-source-maps
143Enable experimental Source Map V3 support for stack traces.
144.
145.It Fl -experimental-import-meta-resolve
146Enable experimental ES modules support for import.meta.resolve().
147.
148.It Fl -experimental-json-modules
149Enable experimental JSON interop support for the ES Module loader.
150.
151.It Fl -experimental-loader Ns = Ns Ar module
152Specify the
153.Ar module
154to use as a custom module loader.
155.
156.It Fl -experimental-policy
157Use the specified file as a security policy.
158.
159.It Fl -experimental-repl-await
160Enable experimental top-level
161.Sy await
162keyword support in REPL.
163.
164.It Fl -experimental-specifier-resolution
165Select extension resolution algorithm for ES Modules; either 'explicit' (default) or 'node'.
166.
167.It Fl -experimental-vm-modules
168Enable experimental ES module support in VM module.
169.
170.It Fl -experimental-wasi-unstable-preview1
171Enable experimental WebAssembly System Interface support.
172.
173.It Fl -experimental-wasm-modules
174Enable experimental WebAssembly module support.
175.
176.It Fl -force-context-aware
177Disable loading native addons that are not context-aware.
178.
179.It Fl -force-fips
180Force FIPS-compliant crypto on startup
181(Cannot be disabled from script code).
182Same requirements as
183.Fl -enable-fips .
184.
185.It Fl -frozen-intrinsics
186Enable experimental frozen intrinsics support.
187.
188.It Fl -heapsnapshot-near-heap-limit Ns = Ns Ar max_count
189Generate heap snapshot when the V8 heap usage is approaching the heap limit.
190No more than the specified number of snapshots will be generated.
191.
192.It Fl -heapsnapshot-signal Ns = Ns Ar signal
193Generate heap snapshot on specified signal.
194.
195.It Fl -heap-prof
196Start the V8 heap profiler on start up, and write the heap profile to disk
197before exit. If
198.Fl -heap-prof-dir
199is not specified, the profile will be written to the current working directory
200with a generated file name.
201.
202.It Fl -heap-prof-dir
203The directory where the heap profiles generated by
204.Fl -heap-prof
205will be placed.
206The default value is controlled by the
207.Fl -diagnostic-dir .
208command-line option.
209.
210.It Fl -heap-prof-interval
211The average sampling interval in bytes for the heap profiles generated by
212.Fl -heap-prof .
213The default is
214.Sy 512 * 1024 .
215.
216.It Fl -heap-prof-name
217File name of the V8 heap profile generated with
218.Fl -heap-prof .
219.
220.It Fl -icu-data-dir Ns = Ns Ar file
221Specify ICU data load path.
222Overrides
223.Ev NODE_ICU_DATA .
224.
225.It Fl -input-type Ns = Ns Ar type
226Set the module resolution type for input via --eval, --print or STDIN.
227.
228.It Fl -inspect-brk Ns = Ns Ar [host:]port
229Activate inspector on
230.Ar host:port
231and break at start of user script.
232.
233.It Fl -inspect-port Ns = Ns Ar [host:]port
234Set the
235.Ar host:port
236to be used when the inspector is activated.
237.
238.It Fl -inspect-publish-uid=stderr,http
239Specify how the inspector WebSocket URL is exposed.
240Valid values are
241.Sy stderr
242and
243.Sy http .
244Default is
245.Sy stderr,http .
246.
247.It Fl -inspect Ns = Ns Ar [host:]port
248Activate inspector on
249.Ar host:port .
250Default is
251.Sy 127.0.0.1:9229 .
252.Pp
253V8 Inspector integration allows attaching Chrome DevTools and IDEs to Node.js instances for debugging and profiling.
254It uses the Chrome DevTools Protocol.
255.
256.It Fl -insecure-http-parser
257Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow
258interoperability with non-conformant HTTP implementations. It may also allow
259request smuggling and other HTTP attacks that rely on invalid headers being
260accepted. Avoid using this option.
261.
262.It Fl -jitless
263Disable runtime allocation of executable memory. This may be required on
264some platforms for security reasons. It can also reduce attack surface on
265other platforms, but the performance impact may be severe.
266.
267.Pp
268This flag is inherited from V8 and is subject to change upstream. It may
269disappear in a non-semver-major release.
270.
271.It Fl -max-http-header-size Ns = Ns Ar size
272Specify the maximum size of HTTP headers in bytes. Defaults to 16KB.
273.
274.It Fl -napi-modules
275This option is a no-op.
276It is kept for compatibility.
277.
278.It Fl -no-deprecation
279Silence deprecation warnings.
280.
281.It Fl -no-force-async-hooks-checks
282Disable runtime checks for `async_hooks`.
283These will still be enabled dynamically when `async_hooks` is enabled.
284.
285.It Fl -no-addons
286Disable the `node-addons` exports condition as well as disable loading native
287addons. When `--no-addons` is specified, calling `process.dlopen` or requiring
288a native C++ addon will fail and throw an exception.
289.
290.It Fl -no-warnings
291Silence all process warnings (including deprecations).
292.
293.It Fl -node-memory-debug
294Enable extra debug checks for memory leaks in Node.js internals. This is
295usually only useful for developers debugging Node.js itself.
296.
297.It Fl -openssl-config Ns = Ns Ar file
298Load an OpenSSL configuration file on startup.
299Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with
300.Sy ./configure --openssl-fips .
301.
302.It Fl -pending-deprecation
303Emit pending deprecation warnings.
304.
305.It Fl -policy-integrity Ns = Ns Ar sri
306Instructs Node.js to error prior to running any code if the policy does not have the specified integrity. It expects a Subresource Integrity string as a parameter.
307.
308.It Fl -preserve-symlinks
309Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
310.
311.It Fl -preserve-symlinks-main
312Instructs the module loader to preserve symbolic links when resolving and caching the main module.
313.
314.It Fl -prof
315Generate V8 profiler output.
316.
317.It Fl -prof-process
318Process V8 profiler output generated using the V8 option
319.Fl -prof .
320.
321.It Fl -redirect-warnings Ns = Ns Ar file
322Write process warnings to the given
323.Ar file
324instead of printing to stderr.
325.
326.It Fl -report-compact
327Write
328.Sy diagnostic reports
329in a compact format, single-line JSON.
330.
331.It Fl -report-dir Fl -report-directory
332Location at which the
333.Sy diagnostic report
334will be generated.
335The `file` name may be an absolute path. If it is not, the default directory it will
336be written to is controlled by the
337.Fl -diagnostic-dir .
338command-line option.
339.
340.It Fl -report-filename
341Name of the file to which the
342.Sy diagnostic report
343will be written.
344.
345.It Fl -report-on-fatalerror
346Enables the
347.Sy diagnostic report
348to be triggered on fatal errors (internal errors within the Node.js runtime such
349as out of memory) that leads to termination of the application. Useful to
350inspect various diagnostic data elements such as heap, stack, event loop state,
351resource consumption etc. to reason about the fatal error.
352.
353.It Fl -report-on-signal
354Enables
355.Sy diagnostic report
356to be generated upon receiving the specified (or predefined) signal to the
357running Node.js process. Default signal is SIGUSR2.
358.
359.It Fl -report-signal
360Sets or resets the signal for
361.Sy diagnostic report
362generation (not supported on Windows). Default signal is SIGUSR2.
363.
364.It Fl -report-uncaught-exception
365Enables
366.Sy diagnostic report
367to be generated on un-caught exceptions. Useful when inspecting JavaScript
368stack in conjunction with native stack and other runtime environment data.
369.
370.It Fl -throw-deprecation
371Throw errors for deprecations.
372.
373.It Fl -title Ns = Ns Ar title
374Specify process.title on startup.
375.
376.It Fl -tls-cipher-list Ns = Ns Ar list
377Specify an alternative default TLS cipher list.
378Requires Node.js to be built with crypto support. (Default)
379.
380.It Fl -tls-keylog Ns = Ns Ar file
381Log TLS key material to a file. The key material is in NSS SSLKEYLOGFILE
382format and can be used by software (such as Wireshark) to decrypt the TLS
383traffic.
384.
385.It Fl -tls-max-v1.2
386Set default  maxVersion to 'TLSv1.2'. Use to disable support for TLSv1.3.
387.
388.It Fl -tls-max-v1.3
389Set default  maxVersion to 'TLSv1.3'. Use to enable support for TLSv1.3.
390.
391.It Fl -tls-min-v1.0
392Set default minVersion to 'TLSv1'. Use for compatibility with old TLS clients
393or servers.
394.
395.It Fl -tls-min-v1.1
396Set default minVersion to 'TLSv1.1'. Use for compatibility with old TLS clients
397or servers.
398.
399.It Fl -tls-min-v1.2
400Set default minVersion to 'TLSv1.2'. This is the default for 12.x and later,
401but the option is supported for compatibility with older Node.js versions.
402.
403.It Fl -tls-min-v1.3
404Set default minVersion to 'TLSv1.3'. Use to disable support for TLSv1.2 in
405favour of TLSv1.3, which is more secure.
406.
407.It Fl -trace-atomics-wait
408Print short summaries of calls to
409.Sy Atomics.wait() .
410.
411.It Fl -trace-deprecation
412Print stack traces for deprecations.
413.
414.It Fl -trace-event-categories Ar categories
415A comma-separated list of categories that should be traced when trace event tracing is enabled using
416.Fl -trace-events-enabled .
417.
418.It Fl -trace-event-file-pattern Ar pattern
419Template string specifying the filepath for the trace event data, it
420supports
421.Sy ${rotation}
422and
423.Sy ${pid} .
424.
425.It Fl -trace-events-enabled
426Enable the collection of trace event tracing information.
427.
428.It Fl -trace-exit
429Prints a stack trace whenever an environment is exited proactively,
430i.e. invoking `process.exit()`.
431.It Fl -trace-sigint
432Prints a stack trace on SIGINT.
433.
434.It Fl -trace-sync-io
435Print a stack trace whenever synchronous I/O is detected after the first turn of the event loop.
436.
437.It Fl -trace-tls
438Prints TLS packet trace information to stderr.
439.
440.It Fl -trace-uncaught
441Print stack traces for uncaught exceptions; usually, the stack trace associated
442with the creation of an
443.Sy Error
444is printed, whereas this makes Node.js also
445print the stack trace associated with throwing the value (which does not need
446to be an
447.Sy Error
448instance).
449.Pp
450Enabling this option may affect garbage collection behavior negatively.
451.
452.It Fl -trace-warnings
453Print stack traces for process warnings (including deprecations).
454.
455.It Fl -track-heap-objects
456Track heap object allocations for heap snapshots.
457.
458.It Fl -unhandled-rejections=mode
459Define the behavior for unhandled rejections. Can be one of `strict` (raise an error), `warn` (enforce warnings) or `none` (silence warnings).
460.
461.It Fl -use-bundled-ca , Fl -use-openssl-ca
462Use bundled Mozilla CA store as supplied by current Node.js version or use OpenSSL's default CA store.
463The default store is selectable at build-time.
464.Pp
465The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store that is fixed at release time.
466It is identical on all supported platforms.
467.Pp
468Using OpenSSL store allows for external modifications of the store.
469For most Linux and BSD distributions, this store is maintained by the distribution maintainers and system administrators.
470OpenSSL CA store location is dependent on configuration of the OpenSSL library but this can be altered at runtime using environment variables.
471.Pp
472See
473.Ev SSL_CERT_DIR
474and
475.Ev SSL_CERT_FILE .
476.
477.It Fl -use-largepages Ns = Ns Ar mode
478Re-map the Node.js static code to large memory pages at startup. If supported on
479the target system, this will cause the Node.js static code to be moved onto 2
480MiB pages instead of 4 KiB pages.
481.Pp
482.Ar mode
483must have one of the following values:
484`off` (the default value, meaning do not map), `on` (map and ignore failure,
485reporting it to stderr), or `silent` (map and silently ignore failure).
486.
487.It Fl -v8-options
488Print V8 command-line options.
489.
490.It Fl -v8-pool-size Ns = Ns Ar num
491Set V8's thread pool size which will be used to allocate background jobs.
492If set to 0 then V8 will choose an appropriate size of the thread pool based on the number of online processors.
493If the value provided is larger than V8's maximum, then the largest value will be chosen.
494.
495.It Fl -zero-fill-buffers
496Automatically zero-fills all newly allocated Buffer and SlowBuffer instances.
497.
498.It Fl c , Fl -check
499Check the script's syntax without executing it.
500Exits with an error code if script is invalid.
501.
502.It Fl e , Fl -eval Ar string
503Evaluate
504.Ar string
505as JavaScript.
506.
507.It Fl h , Fl -help
508Print command-line options.
509The output of this option is less detailed than this document.
510.
511.It Fl i , Fl -interactive
512Open the REPL even if stdin does not appear to be a terminal.
513.
514.It Fl p , Fl -print Ar string
515Identical to
516.Fl e ,
517but prints the result.
518.
519.It Fl r , Fl -require Ar module
520Preload the specified
521.Ar module
522at startup.
523Follows `require()`'s module resolution rules.
524.Ar module
525may be either a path to a file, or a Node.js module name.
526.
527.It Fl v , Fl -version
528Print node's version.
529.El
530.
531.\" =====================================================================
532.Sh ENVIRONMENT
533.Bl -tag -width 6n
534.It Ev FORCE_COLOR
535Used to enable ANSI colorized output. The value may be one of:
536.Ar 1
537,
538.Ar true
539, or
540.Ar an empty string
541to
542indicate 16-color support,
543.Ar 2
544to indicate 256-color support, or
545.Ar 3
546to indicate 16 million-color support. When used and set to a supported
547value, both the NO_COLOR and NODE_DISABLE_COLORS environment variables
548are ignored. Any other value will result in colorized output being
549disabled.
550.
551.It Ev NO_COLOR
552Alias for NODE_DISABLE_COLORS
553.
554.It Ev NODE_DEBUG Ar modules...
555Comma-separated list of core modules that should print debug information.
556.
557.It Ev NODE_DEBUG_NATIVE Ar modules...
558Comma-separated list of C++ core modules that should print debug information.
559.
560.It Ev NODE_DISABLE_COLORS
561When set to
562.Ar 1 ,
563colors will not be used in the REPL.
564.
565.It Ev NODE_EXTRA_CA_CERTS Ar file
566When set, the well-known
567.Dq root
568CAs (like VeriSign) will be extended with the extra certificates in
569.Ar file .
570The file should consist of one or more trusted certificates in PEM format.
571.Pp
572If
573.Ar file
574is missing or misformatted, a message will be emitted once using
575.Sy process.emitWarning() ,
576but any errors are otherwise ignored.
577.Pp
578This environment variable is ignored when `node` runs as setuid root or
579has Linux file capabilities set.
580.Pp
581The
582.Ar NODE_EXTRA_CA_CERTS
583environment variable is only read when the Node.js process is first launched.
584Changing the value at runtime using
585.Ar process.env.NODE_EXTRA_CA_CERTS
586has no effect on the current process.
587.
588.It Ev NODE_ICU_DATA Ar file
589Data path for ICU (Intl object) data.
590Will extend linked-in data when compiled with small-icu support.
591.
592.It Ev NODE_NO_WARNINGS
593When set to
594.Ar 1 ,
595process warnings are silenced.
596.
597.It Ev NODE_OPTIONS Ar options...
598A space-separated list of command-line
599.Ar options ,
600which are interpreted as if they had been specified on the command line before the actual command (so they can be overridden).
601Node.js will exit with an error if an option that is not allowed in the environment is used, such as
602.Fl -print
603or a script file.
604.
605.It Ev NODE_PATH Ar directories...
606A colon-separated list of
607.Ar directories
608prefixed to the module search path.
609.
610.It Ev NODE_PENDING_DEPRECATION
611When set to
612.Ar 1 ,
613emit pending deprecation warnings.
614.
615.It Ev NODE_PRESERVE_SYMLINKS
616When set to
617.Ar 1 ,
618the module loader preserves symbolic links when resolving and caching modules.
619.
620.It Ev NODE_REDIRECT_WARNINGS Ar file
621Write process warnings to the given
622.Ar file
623instead of printing to stderr.
624Equivalent to passing
625.Fl -redirect-warnings Ar file
626on the command line.
627.It Ev NODE_REPL_HISTORY Ar file
628Path to the
629.Ar file
630used to store persistent REPL history.
631The default path is
632.Sy ~/.node_repl_history ,
633which is overridden by this variable.
634Setting the value to an empty string ("" or " ") will disable persistent REPL history.
635.
636.It Ev NODE_SKIP_PLATFORM_CHECK
637When set to
638.Ar 1 ,
639the check for a supported platform is skipped during Node.js startup.
640Node.js might not execute correctly.
641Any issues encountered on unsupported platforms will not be fixed.
642.
643.It Ev NODE_TLS_REJECT_UNAUTHORIZED
644When set to
645.Ar 0 ,
646TLS certificate validation is disabled.
647.
648.It Ev NODE_V8_COVERAGE Ar dir
649When set, Node.js writes JavaScript code coverage information to
650.Ar dir .
651.
652.It Ev OPENSSL_CONF Ar file
653Load an OpenSSL configuration file on startup.
654Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with
655.Sy ./configure --openssl-fips .
656.Pp
657If the
658.Fl -openssl-config
659command-line option is used, this environment variable is ignored.
660.
661.It Ev SSL_CERT_DIR Ar dir
662If
663.Fl -use-openssl-ca
664is enabled, this overrides and sets OpenSSL's directory containing trusted certificates.
665.
666.It Ev SSL_CERT_FILE Ar file
667If
668.Fl -use-openssl-ca
669is enabled, this overrides and sets OpenSSL's file containing trusted certificates.
670.
671.It Ev UV_THREADPOOL_SIZE Ar size
672Sets the number of threads used in libuv's threadpool to
673.Ar size .
674.
675.El
676.\"=====================================================================
677.Sh BUGS
678Bugs are tracked in GitHub Issues:
679.Sy https://github.com/nodejs/node/issues
680.
681.\"======================================================================
682.Sh COPYRIGHT
683Copyright Node.js contributors.
684Node.js is available under the MIT license.
685.
686.Pp
687Node.js also includes external libraries that are available under a variety of licenses.
688See
689.Sy https://github.com/nodejs/node/blob/HEAD/LICENSE
690for the full license text.
691.
692.\"======================================================================
693.Sh SEE ALSO
694Website:
695.Sy https://nodejs.org/
696.
697.Pp
698Documentation:
699.Sy https://nodejs.org/api/
700.
701.Pp
702GitHub repository and issue tracker:
703.Sy https://github.com/nodejs/node
704.
705.Pp
706IRC (general questions):
707.Sy "libera.chat #node.js"
708(unofficial)
709.
710.\"======================================================================
711.Sh AUTHORS
712Written and maintained by 1000+ contributors:
713.Sy https://github.com/nodejs/node/blob/HEAD/AUTHORS
714