# man > nodejs(1) - Duplicate sheet -- please refer instead to: cheat.sh/js: `` *Source: cheat.sh* --- ## NAME node — server-side JavaScript runtime ## SYNOPSIS **node **[_options_] [_v8-options_] [**-e _**string_ | _script.js_ | **-**] [**--**] [_arguments_ _..._] **node inspect **[**-e _**string_ | _script.js_ | **- **| _:_] _..._ **node **[**--v8-options**] ## 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. Execute **node **without arguments to start a REPL. ## OPTIONS **- **Alias for stdin, analogous to the use of - in other command-line utilities. The exe‐ cuted 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. ### -C --conditions _ Use custom conditional exports conditions. _string_ ### --cpu-prof Start the V8 CPU profiler on start up, and write the CPU profile to disk before exit. If **--cpu-prof-dir **is not specified, the profile will be written to the current work‐ ing directory with a generated file name. ### --cpu-prof-dir The directory where the CPU profiles generated by **--cpu-prof **will be placed. The de‐ fault value is controlled by the **--diagnostic-dir**. command-line option. ### --cpu-prof-interval The sampling interval in microseconds for the CPU profiles generated by **--cpu-prof**. The default is **1000**. ### --cpu-prof-name File name of the V8 CPU profile generated with **--cpu-prof**. ### --diagnostic-dir Set the directory for all diagnostic output files. Default is current working direc‐ tory. Set the directory to which all diagnostic output files will be written to. Defaults to current working directory. Affects the default output directory of: **--cpu-prof-dir**. **--heap-prof-dir**. **--redirect-warnings**. **--disable-proto**=_mode_ Disable the `Object.prototype.__proto__` property. If _mode_ is `delete`, the property will be removed entirely. If _mode_ is `throw`, accesses to the property will throw an exception with the code `ERR_PROTO_ACCESS`. ### --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` mod‐ ule. ### --enable-fips Enable FIPS-compliant crypto at startup. Requires Node.js to be built with **./configure --openssl-fips**. ### --enable-source-maps Enable Source Map V3 support for stack traces. **--experimental-default-type**=_type_ Interpret as either ES modules or CommonJS modules input via --eval or STDIN, when --input-type is unspecified; ### --experimental-global-customevent Expose the CustomEvent on the global scope. ### --experimental-global-webcrypto Expose the Web Crypto API on the global scope. ### --experimental-import-meta-resolve Enable experimental ES modules support for import.meta.resolve(). **--experimental-loader**=_module_ Specify the _module_ to use as a custom module loader. ### --experimental-network-imports Enable experimental support for loading modules using `import` over `https:`. ### --experimental-policy Use the specified file as a security policy. ### --experimental-shadow-realm Use this flag to enable ShadowRealm support. ### --experimental-test-coverage Enable code coverage in the test runner. ### --no-experimental-fetch Disable experimental support for the Fetch API. ### --no-experimental-repl-await Disable top-level await keyword support in REPL. ### --experimental-specifier-resolution Select extension resolution algorithm for ES Modules; either 'explicit' (default) or 'node'. ### --experimental-vm-modules Enable experimental ES module support in VM module. ### --experimental-wasi-unstable-preview1 Enable experimental WebAssembly System Interface support. This flag is no longer re‐ quired as WASI is enabled by default. ### --experimental-wasm-modules Enable experimental WebAssembly module support. ### --force-context-aware Disable loading native addons that are not context-aware. ### --force-fips Force FIPS-compliant crypto on startup (Cannot be disabled from script code). Same requirements as **--enable-fips**. ### --frozen-intrinsics Enable experimental frozen intrinsics support. **--heapsnapshot-near-heap-limit**=_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. **--heapsnapshot-signal**=_signal_ Generate heap snapshot on specified signal. ### --heap-prof Start the V8 heap profiler on start up, and write the heap profile to disk before exit. If **--heap-prof-dir **is not specified, the profile will be written to the current working directory with a generated file name. ### --heap-prof-dir The directory where the heap profiles generated by **--heap-prof **will be placed. The default value is controlled by the **--diagnostic-dir**. command-line option. ### --heap-prof-interval The average sampling interval in bytes for the heap profiles generated by **--heap-prof**. The default is **512 * 1024**. ### --heap-prof-name File name of the V8 heap profile generated with **--heap-prof**. **--icu-data-dir**=_file_ Specify ICU data load path. Overrides NODE_ICU_DATA. **--input-type**=_type_ Set the module resolution type for input via --eval, --print or STDIN. **--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-publish-uid=stderr,http Specify how the inspector WebSocket URL is exposed. Valid values are **stderr **and **http**. Default is **stderr,http**. **--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 in‐ stances for debugging and profiling. It uses the Chrome DevTools Protocol. ### --insecure-http-parser Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow inter‐ operability with non-conformant HTTP implementations. It may also allow request smug‐ gling and other HTTP attacks that rely on invalid headers being accepted. Avoid using this option. ### --jitless Disable runtime allocation of executable memory. This may be required on some plat‐ forms for security reasons. It can also reduce attack surface on other platforms, but the performance impact may be severe. This flag is inherited from V8 and is subject to change upstream. It may disappear in a non-semver-major release. **--max-http-header-size**=_size_ Specify the maximum size of HTTP headers in bytes. Defaults to 16 KiB. ### --napi-modules This option is a no-op. It is kept for compatibility. ### --no-deprecation Silence deprecation warnings. ### --no-extra-info-on-fatal-exception Hide extra information on fatal exception that causes exit. ### --no-force-async-hooks-checks Disable runtime checks for `async_hooks`. These will still be enabled dynamically when `async_hooks` is enabled. ### --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. ### --no-global-search-paths Do not search modules from global paths. ### --no-warnings Silence all process warnings (including deprecations). ### --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. **--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. **--policy-integrity**=_sri_ Instructs 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. ### --preserve-symlinks Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module. ### --preserve-symlinks-main Instructs the module loader to preserve symbolic links when resolving 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. ### --report-compact Write **diagnostic reports **in a compact format, single-line JSON. ### --report-dir --report-directory Location at which the **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 con‐ trolled by the **--diagnostic-dir**. command-line option. ### --report-filename Name of the file to which the **diagnostic report **will be written. ### --report-on-fatalerror Enables the **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 applica‐ tion. Useful to inspect various diagnostic data elements such as heap, stack, event loop state, resource consumption etc. to reason about the fatal error. ### --report-on-signal Enables **diagnostic report **to be generated upon receiving the specified (or prede‐ fined) signal to the running Node.js process. Default signal is SIGUSR2. ### --report-signal Sets or resets the signal for **diagnostic report **generation (not supported on Win‐ dows). Default signal is SIGUSR2. ### --report-uncaught-exception Enables **diagnostic report **to be generated on un-caught exceptions. Useful when in‐ specting JavaScript stack in conjunction with native stack and other runtime environ‐ ment data. **--secure-heap**=_n_ Specify the size of the OpenSSL secure heap. Any value less than 2 disables the se‐ cure heap. The default is 0. The value must be a power of two. **--secure-heap-min**=_n_ Specify the minimum allocation from the OpenSSL secure heap. The default is 2. The value must be a power of two. **--test **Starts the Node.js command line test runner. ### --test-concurrency The maximum number of test files that the test runner CLI will execute concurrently. ### --test-name-pattern A regular expression that configures the test runner to only execute tests whose name matches the provided pattern. ### --test-reporter A test reporter to use when running tests. ### --test-reporter-destination The destination for the corresponding test reporter. ### --test-only Configures the test runner to only execute top level tests that have the `only` op‐ tion set. ### --test-shard Test suite shard to execute in a format of /. ### --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) **--tls-keylog**=_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. ### --tls-max-v1.2 Set default maxVersion to 'TLSv1.2'. Use to disable support for TLSv1.3. ### --tls-max-v1.3 Set default maxVersion to 'TLSv1.3'. Use to enable support for TLSv1.3. ### --tls-min-v1.0 Set default minVersion to 'TLSv1'. Use for compatibility with old TLS clients or servers. ### --tls-min-v1.1 Set default minVersion to 'TLSv1.1'. Use for compatibility with old TLS clients or servers. ### --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. ### --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. ### --trace-atomics-wait Print short summaries of calls to **Atomics.wait()**. This flag is deprecated. ### --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-exit Prints a stack trace whenever an environment is exited proactively, i.e. invoking `process.exit()`. ### --trace-sigint Prints a stack trace on SIGINT. ### --trace-sync-io Print a stack trace whenever synchronous I/O is detected after the first turn of the event loop. ### --trace-tls Prints TLS packet trace information to stderr. ### --trace-uncaught Print stack traces for uncaught exceptions; usually, the stack trace associated with the creation of an **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 **Error **in‐ stance). Enabling this option may affect garbage collection behavior negatively. ### --trace-warnings Print stack traces for process warnings (including deprecations). ### --track-heap-objects Track heap object allocations for heap snapshots. ### --unhandled-rejections=mode Define the behavior for unhandled rejections. Can be one of `strict` (raise an er‐ ror), `warn` (enforce warnings) or `none` (silence warnings). **--use-bundled-ca**, **--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. 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 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. See SSL_CERT_DIR and SSL_CERT_FILE. **--use-largepages**=_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. _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). ### --v8-options Print V8 command-line options. **--v8-pool-size**=_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. ### --zero-fill-buffers Automatically zero-fills all newly allocated Buffer and SlowBuffer instances. ### -c --check Check the script's syntax without executing it. Exits with an error code if script is invalid. ### -e --eval _ 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 _ Identical to **-e**, but prints the result. ### -r --require _ 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. ## ENVIRONMENT FORCE_COLOR Used to enable ANSI colorized output. The value may be one of: _1_ , _true_ , or _an_ _empty_ _string_ to indicate 16-color support, _2_ to indicate 256-color support, or _3_ to indi‐ cate 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. NO_COLOR Alias for NODE_DISABLE_COLORS NODE_DEBUG _modules..._ Comma-separated list of core modules that should print debug information. 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 extended with the extra certificates in _file_. The file should consist 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. The _NODE_EXTRA_CA_CERTS_ environment variable is only read when the Node.js process is first launched. Changing the value at runtime using _process.env.NODE_EXTRA_CA_CERTS_ has no effect on the current process. 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 interpreted as if they had been specified on the command line before the actual command (so they can be overrid‐ den). 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 the command line. NODE_REPL_HISTORY _file_ Path to the _file_ used to store persistent REPL history. The default 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_REPL_EXTERNAL_MODULE _file_ Path to a Node.js module which will be loaded in place of the built-in REPL. Over‐ riding this value to an empty string (`''`) will use the built-in REPL. NODE_SKIP_PLATFORM_CHECK When set to _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. 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 environment variable is ig‐ nored. SSL_CERT_DIR _dir_ If **--use-openssl-ca **is enabled, this overrides and sets OpenSSL's directory contain‐ ing trusted certificates. SSL_CERT_FILE _file_ If **--use-openssl-ca **is enabled, this overrides and sets OpenSSL's file containing trusted certificates. TZ Specify the timezone configuration. UV_THREADPOOL_SIZE _size_ Sets the number of threads used in libuv's threadpool to _size_. ## BUGS Bugs are tracked in GitHub Issues: **** ## COPYRIGHT Copyright Node.js contributors. Node.js is available under the MIT license. Node.js also includes external libraries that are available under a variety of licenses. See ** **for the full license text. ## SEE ALSO Website: **** Documentation: **** GitHub repository and issue tracker: **** IRC (general questions): **libera.chat #node.js **(unofficial) ## AUTHORS Written and maintained by 1000+ contributors: ### 2018 [_NODE_(1)](https://www.chedong.com/phpMan.php/man/NODE/1/markdown)