1<!DOCTYPE html> 2<html lang="en"> 3<head> 4 <meta charset="utf-8"> 5 <meta name="viewport" content="width=device-width"> 6 <meta name="nodejs.org:node-version" content="v14.20.1"> 7 <title>Command-line options | Node.js v14.20.1 Documentation</title> 8 <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Lato:400,700,400italic&display=fallback"> 9 <link rel="stylesheet" href="assets/style.css"> 10 <link rel="stylesheet" href="assets/hljs.css"> 11 <link rel="canonical" href="https://nodejs.org/api/cli.html"> 12</head> 13<body class="alt apidoc" id="api-section-cli"> 14 <div id="content" class="clearfix"> 15 <div id="column2" class="interior"> 16 <div id="intro" class="interior"> 17 <a href="/" title="Go back to the home page"> 18 Node.js 19 </a> 20 </div> 21 <ul> 22<li><a href="documentation.html" class="nav-documentation">About this documentation</a></li> 23<li><a href="synopsis.html" class="nav-synopsis">Usage and example</a></li> 24</ul> 25<hr class="line"> 26<ul> 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data-id="cli" class="interior"> 90 <header> 91 <div class="header-container"> 92 <h1>Node.js v14.20.1 documentation</h1> 93 <button class="theme-toggle-btn" id="theme-toggle-btn" title="Toggle dark mode/light mode" aria-label="Toggle dark mode/light mode" hidden> 94 <svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" height="24" width="24"> 95 <path fill="none" d="M0 0h24v24H0z" /> 96 <path d="M11.1 12.08c-2.33-4.51-.5-8.48.53-10.07C6.27 2.2 1.98 6.59 1.98 12c0 .14.02.28.02.42.62-.27 1.29-.42 2-.42 1.66 0 3.18.83 4.1 2.15A4.01 4.01 0 0111 18c0 1.52-.87 2.83-2.12 3.51.98.32 2.03.5 3.11.5 3.5 0 6.58-1.8 8.37-4.52-2.36.23-6.98-.97-9.26-5.41z"/> 97 <path d="M7 16h-.18C6.4 14.84 5.3 14 4 14c-1.66 0-3 1.34-3 3s1.34 3 3 3h3c1.1 0 2-.9 2-2s-.9-2-2-2z"/> 98 </svg> 99 <svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" height="24" width="24"> 100 <path d="M0 0h24v24H0z" fill="none" /> 101 <path d="M6.76 4.84l-1.8-1.79-1.41 1.41 1.79 1.79 1.42-1.41zM4 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140 141 <details id="toc" open><summary>Table of contents</summary><ul> 142<li><a href="#cli_command_line_options">Command-line options</a> 143<ul> 144<li><a href="#cli_synopsis">Synopsis</a></li> 145<li><a href="#cli_options">Options</a> 146<ul> 147<li><a href="#cli"><code>-</code></a></li> 148<li><a href="#cli_1"><code>--</code></a></li> 149<li><a href="#cli_abort_on_uncaught_exception"><code>--abort-on-uncaught-exception</code></a></li> 150<li><a href="#cli_completion_bash"><code>--completion-bash</code></a></li> 151<li><span class="stability_1"><a href="#cli_c_condition_conditions_condition"><code>-C=condition</code>, <code>--conditions=condition</code></a></span></li> 152<li><span class="stability_1"><a href="#cli_cpu_prof"><code>--cpu-prof</code></a></span></li> 153<li><span class="stability_1"><a href="#cli_cpu_prof_dir"><code>--cpu-prof-dir</code></a></span></li> 154<li><span class="stability_1"><a href="#cli_cpu_prof_interval"><code>--cpu-prof-interval</code></a></span></li> 155<li><span class="stability_1"><a href="#cli_cpu_prof_name"><code>--cpu-prof-name</code></a></span></li> 156<li><a href="#cli_diagnostic_dir_directory"><code>--diagnostic-dir=directory</code></a></li> 157<li><a href="#cli_disable_proto_mode"><code>--disable-proto=mode</code></a></li> 158<li><a href="#cli_disallow_code_generation_from_strings"><code>--disallow-code-generation-from-strings</code></a></li> 159<li><a href="#cli_dns_result_order_order"><code>--dns-result-order=order</code></a></li> 160<li><a href="#cli_enable_fips"><code>--enable-fips</code></a></li> 161<li><a href="#cli_enable_source_maps"><code>--enable-source-maps</code></a></li> 162<li><a href="#cli_experimental_abortcontroller"><code>--experimental-abortcontroller</code></a></li> 163<li><a href="#cli_experimental_import_meta_resolve"><code>--experimental-import-meta-resolve</code></a></li> 164<li><a href="#cli_experimental_json_modules"><code>--experimental-json-modules</code></a></li> 165<li><a href="#cli_experimental_loader_module"><code>--experimental-loader=module</code></a></li> 166<li><a href="#cli_experimental_modules"><code>--experimental-modules</code></a></li> 167<li><a href="#cli_experimental_policy"><code>--experimental-policy</code></a></li> 168<li><a href="#cli_experimental_repl_await"><code>--experimental-repl-await</code></a></li> 169<li><a href="#cli_experimental_specifier_resolution_mode"><code>--experimental-specifier-resolution=mode</code></a></li> 170<li><a href="#cli_experimental_vm_modules"><code>--experimental-vm-modules</code></a></li> 171<li><a href="#cli_experimental_wasi_unstable_preview1"><code>--experimental-wasi-unstable-preview1</code></a></li> 172<li><a href="#cli_experimental_wasm_modules"><code>--experimental-wasm-modules</code></a></li> 173<li><a href="#cli_force_context_aware"><code>--force-context-aware</code></a></li> 174<li><a href="#cli_force_fips"><code>--force-fips</code></a></li> 175<li><span class="stability_1"><a href="#cli_frozen_intrinsics"><code>--frozen-intrinsics</code></a></span></li> 176<li><span class="stability_1"><a href="#cli_heapsnapshot_near_heap_limit_max_count"><code>--heapsnapshot-near-heap-limit=max_count</code></a></span></li> 177<li><a href="#cli_heapsnapshot_signal_signal"><code>--heapsnapshot-signal=signal</code></a></li> 178<li><span class="stability_1"><a href="#cli_heap_prof"><code>--heap-prof</code></a></span></li> 179<li><span class="stability_1"><a href="#cli_heap_prof_dir"><code>--heap-prof-dir</code></a></span></li> 180<li><span class="stability_1"><a href="#cli_heap_prof_interval"><code>--heap-prof-interval</code></a></span></li> 181<li><span class="stability_1"><a href="#cli_heap_prof_name"><code>--heap-prof-name</code></a></span></li> 182<li><a href="#cli_icu_data_dir_file"><code>--icu-data-dir=file</code></a></li> 183<li><a href="#cli_input_type_type"><code>--input-type=type</code></a></li> 184<li><a href="#cli_inspect_brk_host_port"><code>--inspect-brk[=[host:]port]</code></a></li> 185<li><a href="#cli_inspect_port_host_port"><code>--inspect-port=[host:]port</code></a></li> 186<li><a href="#cli_inspect_host_port"><code>--inspect[=[host:]port]</code></a> 187<ul> 188<li><a href="#cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure">Warning: binding inspector to a public IP:port combination is insecure</a></li> 189</ul> 190</li> 191<li><a href="#cli_inspect_publish_uid_stderr_http"><code>--inspect-publish-uid=stderr,http</code></a></li> 192<li><a href="#cli_insecure_http_parser"><code>--insecure-http-parser</code></a></li> 193<li><a href="#cli_jitless"><code>--jitless</code></a></li> 194<li><a href="#cli_max_http_header_size_size"><code>--max-http-header-size=size</code></a></li> 195<li><a href="#cli_napi_modules"><code>--napi-modules</code></a></li> 196<li><a href="#cli_no_addons"><code>--no-addons</code></a></li> 197<li><a href="#cli_no_deprecation"><code>--no-deprecation</code></a></li> 198<li><a href="#cli_no_force_async_hooks_checks"><code>--no-force-async-hooks-checks</code></a></li> 199<li><a href="#cli_no_warnings"><code>--no-warnings</code></a></li> 200<li><a href="#cli_node_memory_debug"><code>--node-memory-debug</code></a></li> 201<li><a href="#cli_openssl_config_file"><code>--openssl-config=file</code></a></li> 202<li><a href="#cli_pending_deprecation"><code>--pending-deprecation</code></a></li> 203<li><span class="stability_1"><a href="#cli_policy_integrity_sri"><code>--policy-integrity=sri</code></a></span></li> 204<li><a href="#cli_preserve_symlinks"><code>--preserve-symlinks</code></a></li> 205<li><a href="#cli_preserve_symlinks_main"><code>--preserve-symlinks-main</code></a></li> 206<li><a href="#cli_prof"><code>--prof</code></a></li> 207<li><a href="#cli_prof_process"><code>--prof-process</code></a></li> 208<li><a href="#cli_redirect_warnings_file"><code>--redirect-warnings=file</code></a></li> 209<li><a href="#cli_report_compact"><code>--report-compact</code></a></li> 210<li><a href="#cli_report_dir_directory_report_directory_directory"><code>--report-dir=directory</code>, <code>report-directory=directory</code></a></li> 211<li><a href="#cli_report_filename_filename"><code>--report-filename=filename</code></a></li> 212<li><a href="#cli_report_on_fatalerror"><code>--report-on-fatalerror</code></a></li> 213<li><a href="#cli_report_on_signal"><code>--report-on-signal</code></a></li> 214<li><a href="#cli_report_signal_signal"><code>--report-signal=signal</code></a></li> 215<li><a href="#cli_report_uncaught_exception"><code>--report-uncaught-exception</code></a></li> 216<li><a href="#cli_throw_deprecation"><code>--throw-deprecation</code></a></li> 217<li><a href="#cli_title_title"><code>--title=title</code></a></li> 218<li><a href="#cli_tls_cipher_list_list"><code>--tls-cipher-list=list</code></a></li> 219<li><a href="#cli_tls_keylog_file"><code>--tls-keylog=file</code></a></li> 220<li><a href="#cli_tls_max_v1_2"><code>--tls-max-v1.2</code></a></li> 221<li><a href="#cli_tls_max_v1_3"><code>--tls-max-v1.3</code></a></li> 222<li><a href="#cli_tls_min_v1_0"><code>--tls-min-v1.0</code></a></li> 223<li><a href="#cli_tls_min_v1_1"><code>--tls-min-v1.1</code></a></li> 224<li><a href="#cli_tls_min_v1_2"><code>--tls-min-v1.2</code></a></li> 225<li><a href="#cli_tls_min_v1_3"><code>--tls-min-v1.3</code></a></li> 226<li><a href="#cli_trace_atomics_wait"><code>--trace-atomics-wait</code></a></li> 227<li><a href="#cli_trace_deprecation"><code>--trace-deprecation</code></a></li> 228<li><a href="#cli_trace_event_categories"><code>--trace-event-categories</code></a></li> 229<li><a href="#cli_trace_event_file_pattern"><code>--trace-event-file-pattern</code></a></li> 230<li><a href="#cli_trace_events_enabled"><code>--trace-events-enabled</code></a></li> 231<li><a href="#cli_trace_exit"><code>--trace-exit</code></a></li> 232<li><a href="#cli_trace_sigint"><code>--trace-sigint</code></a></li> 233<li><a href="#cli_trace_sync_io"><code>--trace-sync-io</code></a></li> 234<li><a href="#cli_trace_tls"><code>--trace-tls</code></a></li> 235<li><a href="#cli_trace_uncaught"><code>--trace-uncaught</code></a></li> 236<li><a href="#cli_trace_warnings"><code>--trace-warnings</code></a></li> 237<li><a href="#cli_track_heap_objects"><code>--track-heap-objects</code></a></li> 238<li><a href="#cli_unhandled_rejections_mode"><code>--unhandled-rejections=mode</code></a></li> 239<li><a href="#cli_use_bundled_ca_use_openssl_ca"><code>--use-bundled-ca</code>, <code>--use-openssl-ca</code></a></li> 240<li><a href="#cli_use_largepages_mode"><code>--use-largepages=mode</code></a></li> 241<li><a href="#cli_v8_options"><code>--v8-options</code></a></li> 242<li><a href="#cli_v8_pool_size_num"><code>--v8-pool-size=num</code></a></li> 243<li><a href="#cli_zero_fill_buffers"><code>--zero-fill-buffers</code></a></li> 244<li><a href="#cli_c_check"><code>-c</code>, <code>--check</code></a></li> 245<li><a href="#cli_e_eval_script"><code>-e</code>, <code>--eval "script"</code></a></li> 246<li><a href="#cli_h_help"><code>-h</code>, <code>--help</code></a></li> 247<li><a href="#cli_i_interactive"><code>-i</code>, <code>--interactive</code></a></li> 248<li><a href="#cli_p_print_script"><code>-p</code>, <code>--print "script"</code></a></li> 249<li><a href="#cli_r_require_module"><code>-r</code>, <code>--require module</code></a></li> 250<li><a href="#cli_v_version"><code>-v</code>, <code>--version</code></a></li> 251</ul> 252</li> 253<li><a href="#cli_environment_variables">Environment variables</a> 254<ul> 255<li><a href="#cli_force_color_1_2_3"><code>FORCE_COLOR=[1, 2, 3]</code></a></li> 256<li><a href="#cli_node_debug_module"><code>NODE_DEBUG=module[,…]</code></a></li> 257<li><a href="#cli_node_debug_native_module"><code>NODE_DEBUG_NATIVE=module[,…]</code></a></li> 258<li><a href="#cli_node_disable_colors_1"><code>NODE_DISABLE_COLORS=1</code></a></li> 259<li><a href="#cli_node_extra_ca_certs_file"><code>NODE_EXTRA_CA_CERTS=file</code></a></li> 260<li><a href="#cli_node_icu_data_file"><code>NODE_ICU_DATA=file</code></a></li> 261<li><a href="#cli_node_no_warnings_1"><code>NODE_NO_WARNINGS=1</code></a></li> 262<li><a href="#cli_node_options_options"><code>NODE_OPTIONS=options...</code></a></li> 263<li><a href="#cli_node_path_path"><code>NODE_PATH=path[:…]</code></a></li> 264<li><a href="#cli_node_pending_deprecation_1"><code>NODE_PENDING_DEPRECATION=1</code></a></li> 265<li><a href="#cli_node_pending_pipe_instances_instances"><code>NODE_PENDING_PIPE_INSTANCES=instances</code></a></li> 266<li><a href="#cli_node_preserve_symlinks_1"><code>NODE_PRESERVE_SYMLINKS=1</code></a></li> 267<li><a href="#cli_node_redirect_warnings_file"><code>NODE_REDIRECT_WARNINGS=file</code></a></li> 268<li><a href="#cli_node_repl_history_file"><code>NODE_REPL_HISTORY=file</code></a></li> 269<li><a href="#cli_node_repl_external_module_file"><code>NODE_REPL_EXTERNAL_MODULE=file</code></a></li> 270<li><a href="#cli_node_skip_platform_check_value"><code>NODE_SKIP_PLATFORM_CHECK=value</code></a></li> 271<li><a href="#cli_node_tls_reject_unauthorized_value"><code>NODE_TLS_REJECT_UNAUTHORIZED=value</code></a></li> 272<li><a href="#cli_node_v8_coverage_dir"><code>NODE_V8_COVERAGE=dir</code></a> 273<ul> 274<li><a href="#cli_coverage_output">Coverage output</a></li> 275<li><span class="stability_1"><a href="#cli_source_map_cache">Source map cache</a></span></li> 276</ul> 277</li> 278<li><a href="#cli_no_color_any"><code>NO_COLOR=<any></code></a></li> 279<li><a href="#cli_openssl_conf_file"><code>OPENSSL_CONF=file</code></a></li> 280<li><a href="#cli_ssl_cert_dir_dir"><code>SSL_CERT_DIR=dir</code></a></li> 281<li><a href="#cli_ssl_cert_file_file"><code>SSL_CERT_FILE=file</code></a></li> 282<li><a href="#cli_uv_threadpool_size_size"><code>UV_THREADPOOL_SIZE=size</code></a></li> 283</ul> 284</li> 285<li><a href="#cli_useful_v8_options">Useful V8 options</a> 286<ul> 287<li><a href="#cli_max_old_space_size_size_in_megabytes"><code>--max-old-space-size=SIZE</code> (in megabytes)</a></li> 288</ul> 289</li> 290</ul> 291</li> 292</ul></details> 293 294 <div id="apicontent"> 295 <h2>Command-line options<span><a class="mark" href="#cli_command_line_options" id="cli_command_line_options">#</a></span></h2> 296 297 298<p>Node.js comes with a variety of CLI options. These options expose built-in 299debugging, multiple ways to execute scripts, and other helpful runtime options.</p> 300<p>To view this documentation as a manual page in a terminal, run <code>man node</code>.</p> 301<section><h3>Synopsis<span><a class="mark" href="#cli_synopsis" id="cli_synopsis">#</a></span></h3> 302<p><code>node [options] [V8 options] [script.js | -e "script" | -] [--] [arguments]</code></p> 303<p><code>node inspect [script.js | -e "script" | <host>:<port>] …</code></p> 304<p><code>node --v8-options</code></p> 305<p>Execute without arguments to start the <a href="repl.html">REPL</a>.</p> 306<p>For more info about <code>node inspect</code>, see the <a href="debugger.html">debugger</a> documentation.</p> 307</section><section><h3>Options<span><a class="mark" href="#cli_options" id="cli_options">#</a></span></h3> 308<div class="api_metadata"> 309<details class="changelog"><summary>History</summary> 310<table> 311<tbody><tr><th>Version</th><th>Changes</th></tr> 312<tr><td>v10.12.0</td> 313<td><p>Underscores instead of dashes are now allowed for Node.js options as well, in addition to V8 options.</p></td></tr> 314</tbody></table> 315</details> 316</div> 317<p>All options, including V8 options, allow words to be separated by both 318dashes (<code>-</code>) or underscores (<code>_</code>). For example, <code>--pending-deprecation</code> is 319equivalent to <code>--pending_deprecation</code>.</p> 320<p>If an option that takes a single value (such as <code>--max-http-header-size</code>) is 321passed more than once, then the last passed value is used. Options from the 322command line take precedence over options passed through the <a href="#cli_node_options_options"><code>NODE_OPTIONS</code></a> 323environment variable.</p> 324<h4><code>-</code><span><a class="mark" href="#cli" id="cli">#</a></span></h4> 325<div class="api_metadata"> 326<span>Added in: v8.0.0</span> 327</div> 328<p>Alias for stdin. Analogous to the use of <code>-</code> in other command-line utilities, 329meaning that the script is read from stdin, and the rest of the options 330are passed to that script.</p> 331<h4><code>--</code><span><a class="mark" href="#cli_1" id="cli_1">#</a></span></h4> 332<div class="api_metadata"> 333<span>Added in: v6.11.0</span> 334</div> 335<p>Indicate the end of node options. Pass the rest of the arguments to the script. 336If no script filename or eval/print script is supplied prior to this, then 337the next argument is used as a script filename.</p> 338<h4><code>--abort-on-uncaught-exception</code><span><a class="mark" href="#cli_abort_on_uncaught_exception" id="cli_abort_on_uncaught_exception">#</a></span></h4> 339<div class="api_metadata"> 340<span>Added in: v0.10.8</span> 341</div> 342<p>Aborting instead of exiting causes a core file to be generated for post-mortem 343analysis using a debugger (such as <code>lldb</code>, <code>gdb</code>, and <code>mdb</code>).</p> 344<p>If this flag is passed, the behavior can still be set to not abort through 345<a href="process.html#process_process_setuncaughtexceptioncapturecallback_fn"><code>process.setUncaughtExceptionCaptureCallback()</code></a> (and through usage of the 346<code>domain</code> module that uses it).</p> 347<h4><code>--completion-bash</code><span><a class="mark" href="#cli_completion_bash" id="cli_completion_bash">#</a></span></h4> 348<div class="api_metadata"> 349<span>Added in: v10.12.0</span> 350</div> 351<p>Print source-able bash completion script for Node.js.</p> 352<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --completion-bash > node_bash_completion</span> 353<span class="hljs-meta">$ </span><span class="language-bash"><span class="hljs-built_in">source</span> node_bash_completion</span></code></pre> 354<h4><code>-C=condition</code>, <code>--conditions=condition</code><span><a class="mark" href="#cli_c_condition_conditions_condition" id="cli_c_condition_conditions_condition">#</a></span></h4> 355<div class="api_metadata"> 356<span>Added in: v14.9.0</span> 357</div> 358<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 359<p>Enable experimental support for custom <a href="packages.html#packages_conditional_exports">conditional exports</a> resolution 360conditions.</p> 361<p>Any number of custom string condition names are permitted.</p> 362<p>The default Node.js conditions of <code>"node"</code>, <code>"default"</code>, <code>"import"</code>, and 363<code>"require"</code> will always apply as defined.</p> 364<p>For example, to run a module with "development" resolutions:</p> 365<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node -C=development app.js</span></code></pre> 366<h4><code>--cpu-prof</code><span><a class="mark" href="#cli_cpu_prof" id="cli_cpu_prof">#</a></span></h4> 367<div class="api_metadata"> 368<span>Added in: v12.0.0</span> 369</div> 370<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 371<p>Starts the V8 CPU profiler on start up, and writes the CPU profile to disk 372before exit.</p> 373<p>If <code>--cpu-prof-dir</code> is not specified, the generated profile is placed 374in the current working directory.</p> 375<p>If <code>--cpu-prof-name</code> is not specified, the generated profile is 376named <code>CPU.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.cpuprofile</code>.</p> 377<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --cpu-prof index.js</span> 378<span class="hljs-meta">$ </span><span class="language-bash">ls *.cpuprofile</span> 379CPU.20190409.202950.15293.0.0.cpuprofile</code></pre> 380<h4><code>--cpu-prof-dir</code><span><a class="mark" href="#cli_cpu_prof_dir" id="cli_cpu_prof_dir">#</a></span></h4> 381<div class="api_metadata"> 382<span>Added in: v12.0.0</span> 383</div> 384<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 385<p>Specify the directory where the CPU profiles generated by <code>--cpu-prof</code> will 386be placed.</p> 387<p>The default value is controlled by the 388<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p> 389<h4><code>--cpu-prof-interval</code><span><a class="mark" href="#cli_cpu_prof_interval" id="cli_cpu_prof_interval">#</a></span></h4> 390<div class="api_metadata"> 391<span>Added in: v12.2.0</span> 392</div> 393<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 394<p>Specify the sampling interval in microseconds for the CPU profiles generated 395by <code>--cpu-prof</code>. The default is 1000 microseconds.</p> 396<h4><code>--cpu-prof-name</code><span><a class="mark" href="#cli_cpu_prof_name" id="cli_cpu_prof_name">#</a></span></h4> 397<div class="api_metadata"> 398<span>Added in: v12.0.0</span> 399</div> 400<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 401<p>Specify the file name of the CPU profile generated by <code>--cpu-prof</code>.</p> 402<h4><code>--diagnostic-dir=directory</code><span><a class="mark" href="#cli_diagnostic_dir_directory" id="cli_diagnostic_dir_directory">#</a></span></h4> 403<p>Set the directory to which all diagnostic output files are written. 404Defaults to current working directory.</p> 405<p>Affects the default output directory of:</p> 406<ul> 407<li><a href="#cli_cpu_prof_dir">--cpu-prof-dir</a></li> 408<li><a href="#cli_heap_prof_dir">--heap-prof-dir</a></li> 409<li><a href="#cli_redirect_warnings_file">--redirect-warnings</a></li> 410</ul> 411<h4><code>--disable-proto=mode</code><span><a class="mark" href="#cli_disable_proto_mode" id="cli_disable_proto_mode">#</a></span></h4> 412<div class="api_metadata"> 413<span>Added in: v13.12.0</span> 414</div> 415<p>Disable the <code>Object.prototype.__proto__</code> property. If <code>mode</code> is <code>delete</code>, the 416property is removed entirely. If <code>mode</code> is <code>throw</code>, accesses to the 417property throw an exception with the code <code>ERR_PROTO_ACCESS</code>.</p> 418<h4><code>--disallow-code-generation-from-strings</code><span><a class="mark" href="#cli_disallow_code_generation_from_strings" id="cli_disallow_code_generation_from_strings">#</a></span></h4> 419<div class="api_metadata"> 420<span>Added in: v9.8.0</span> 421</div> 422<p>Make built-in language features like <code>eval</code> and <code>new Function</code> that generate 423code from strings throw an exception instead. This does not affect the Node.js 424<code>vm</code> module.</p> 425<h4><code>--dns-result-order=order</code><span><a class="mark" href="#cli_dns_result_order_order" id="cli_dns_result_order_order">#</a></span></h4> 426<div class="api_metadata"> 427<span>Added in: v14.18.0</span> 428</div> 429<p>Set the default value of <code>verbatim</code> in <a href="dns.html#dns_dns_lookup_hostname_options_callback"><code>dns.lookup()</code></a> and 430<a href="dns.html#dns_dnspromises_lookup_hostname_options"><code>dnsPromises.lookup()</code></a>. The value could be:</p> 431<ul> 432<li><code>ipv4first</code>: sets default <code>verbatim</code> <code>false</code>.</li> 433<li><code>verbatim</code>: sets default <code>verbatim</code> <code>true</code>.</li> 434</ul> 435<p>The default is <code>ipv4first</code> and <a href="dns.html#dns_dns_setdefaultresultorder_order"><code>dns.setDefaultResultOrder()</code></a> have higher 436priority than <code>--dns-result-order</code>.</p> 437<h4><code>--enable-fips</code><span><a class="mark" href="#cli_enable_fips" id="cli_enable_fips">#</a></span></h4> 438<div class="api_metadata"> 439<span>Added in: v6.0.0</span> 440</div> 441<p>Enable FIPS-compliant crypto at startup. (Requires Node.js to be built 442against FIPS-compatible OpenSSL.)</p> 443<h4><code>--enable-source-maps</code><span><a class="mark" href="#cli_enable_source_maps" id="cli_enable_source_maps">#</a></span></h4> 444<div class="api_metadata"> 445<details class="changelog"><summary>History</summary> 446<table> 447<tbody><tr><th>Version</th><th>Changes</th></tr> 448<tr><td>v14.18.0</td> 449<td><p>This API is no longer experimental.</p></td></tr> 450<tr><td>v12.12.0</td> 451<td><p><span>Added in: v12.12.0</span></p></td></tr> 452</tbody></table> 453</details> 454</div> 455<p>Enable <a href="https://sourcemaps.info/spec.html">Source Map v3</a> support for stack traces.</p> 456<p>When using a transpiler, such as TypeScript, strack traces thrown by an 457application reference the transpiled code, not the original source position. 458<code>--enable-source-maps</code> enables caching of Source Maps and makes a best 459effort to report stack traces relative to the original source file.</p> 460<p>Overriding <code>Error.prepareStackTrace</code> prevents <code>--enable-source-maps</code> from 461modifiying the stack trace.</p> 462<h4><code>--experimental-abortcontroller</code><span><a class="mark" href="#cli_experimental_abortcontroller" id="cli_experimental_abortcontroller">#</a></span></h4> 463<div class="api_metadata"> 464<span>Added in: v14.17.0</span> 465</div> 466<p>Enable experimental <code>AbortController</code> and <code>AbortSignal</code> support.</p> 467<h4><code>--experimental-import-meta-resolve</code><span><a class="mark" href="#cli_experimental_import_meta_resolve" id="cli_experimental_import_meta_resolve">#</a></span></h4> 468<div class="api_metadata"> 469<span>Added in: v13.9.0, v12.16.2</span> 470</div> 471<p>Enable experimental <code>import.meta.resolve()</code> support.</p> 472<h4><code>--experimental-json-modules</code><span><a class="mark" href="#cli_experimental_json_modules" id="cli_experimental_json_modules">#</a></span></h4> 473<div class="api_metadata"> 474<span>Added in: v12.9.0</span> 475</div> 476<p>Enable experimental JSON support for the ES Module loader.</p> 477<h4><code>--experimental-loader=module</code><span><a class="mark" href="#cli_experimental_loader_module" id="cli_experimental_loader_module">#</a></span></h4> 478<div class="api_metadata"> 479<span>Added in: v9.0.0</span> 480</div> 481<p>Specify the <code>module</code> of a custom experimental <a href="esm.html#esm_loaders">ECMAScript Module loader</a>. 482<code>module</code> may be either a path to a file, or an ECMAScript Module name.</p> 483<h4><code>--experimental-modules</code><span><a class="mark" href="#cli_experimental_modules" id="cli_experimental_modules">#</a></span></h4> 484<div class="api_metadata"> 485<span>Added in: v8.5.0</span> 486</div> 487<p>Enable latest experimental modules features (deprecated).</p> 488<h4><code>--experimental-policy</code><span><a class="mark" href="#cli_experimental_policy" id="cli_experimental_policy">#</a></span></h4> 489<div class="api_metadata"> 490<span>Added in: v11.8.0</span> 491</div> 492<p>Use the specified file as a security policy.</p> 493<h4><code>--experimental-repl-await</code><span><a class="mark" href="#cli_experimental_repl_await" id="cli_experimental_repl_await">#</a></span></h4> 494<div class="api_metadata"> 495<span>Added in: v10.0.0</span> 496</div> 497<p>Enable experimental top-level <code>await</code> keyword support in REPL.</p> 498<h4><code>--experimental-specifier-resolution=mode</code><span><a class="mark" href="#cli_experimental_specifier_resolution_mode" id="cli_experimental_specifier_resolution_mode">#</a></span></h4> 499<div class="api_metadata"> 500<span>Added in: v13.4.0, v12.16.0</span> 501</div> 502<p>Sets the resolution algorithm for resolving ES module specifiers. Valid options 503are <code>explicit</code> and <code>node</code>.</p> 504<p>The default is <code>explicit</code>, which requires providing the full path to a 505module. The <code>node</code> mode enables support for optional file extensions and 506the ability to import a directory that has an index file.</p> 507<p>See <a href="esm.html#esm_customizing_esm_specifier_resolution_algorithm">customizing ESM specifier resolution</a> for example usage.</p> 508<h4><code>--experimental-vm-modules</code><span><a class="mark" href="#cli_experimental_vm_modules" id="cli_experimental_vm_modules">#</a></span></h4> 509<div class="api_metadata"> 510<span>Added in: v9.6.0</span> 511</div> 512<p>Enable experimental ES Module support in the <code>vm</code> module.</p> 513<h4><code>--experimental-wasi-unstable-preview1</code><span><a class="mark" href="#cli_experimental_wasi_unstable_preview1" id="cli_experimental_wasi_unstable_preview1">#</a></span></h4> 514<div class="api_metadata"> 515<details class="changelog"><summary>History</summary> 516<table> 517<tbody><tr><th>Version</th><th>Changes</th></tr> 518<tr><td>v13.6.0</td> 519<td><p>changed from <code>--experimental-wasi-unstable-preview0</code> to <code>--experimental-wasi-unstable-preview1</code>.</p></td></tr> 520<tr><td>v13.3.0, v12.16.0</td> 521<td><p><span>Added in: v13.3.0, v12.16.0</span></p></td></tr> 522</tbody></table> 523</details> 524</div> 525<p>Enable experimental WebAssembly System Interface (WASI) support.</p> 526<h4><code>--experimental-wasm-modules</code><span><a class="mark" href="#cli_experimental_wasm_modules" id="cli_experimental_wasm_modules">#</a></span></h4> 527<div class="api_metadata"> 528<span>Added in: v12.3.0</span> 529</div> 530<p>Enable experimental WebAssembly module support.</p> 531<h4><code>--force-context-aware</code><span><a class="mark" href="#cli_force_context_aware" id="cli_force_context_aware">#</a></span></h4> 532<div class="api_metadata"> 533<span>Added in: v12.12.0</span> 534</div> 535<p>Disable loading native addons that are not <a href="addons.html#addons_context_aware_addons">context-aware</a>.</p> 536<h4><code>--force-fips</code><span><a class="mark" href="#cli_force_fips" id="cli_force_fips">#</a></span></h4> 537<div class="api_metadata"> 538<span>Added in: v6.0.0</span> 539</div> 540<p>Force FIPS-compliant crypto on startup. (Cannot be disabled from script code.) 541(Same requirements as <code>--enable-fips</code>.)</p> 542<h4><code>--frozen-intrinsics</code><span><a class="mark" href="#cli_frozen_intrinsics" id="cli_frozen_intrinsics">#</a></span></h4> 543<div class="api_metadata"> 544<span>Added in: v11.12.0</span> 545</div> 546<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 547<p>Enable experimental frozen intrinsics like <code>Array</code> and <code>Object</code>.</p> 548<p>Support is currently only provided for the root context and no guarantees are 549currently provided that <code>global.Array</code> is indeed the default intrinsic 550reference. Code may break under this flag.</p> 551<p><code>--require</code> runs prior to freezing intrinsics in order to allow polyfills to 552be added.</p> 553<h4><code>--heapsnapshot-near-heap-limit=max_count</code><span><a class="mark" href="#cli_heapsnapshot_near_heap_limit_max_count" id="cli_heapsnapshot_near_heap_limit_max_count">#</a></span></h4> 554<div class="api_metadata"> 555<span>Added in: v14.18.0</span> 556</div> 557<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 558<p>Writes a V8 heap snapshot to disk when the V8 heap usage is approaching the 559heap limit. <code>count</code> should be a non-negative integer (in which case 560Node.js will write no more than <code>max_count</code> snapshots to disk).</p> 561<p>When generating snapshots, garbage collection may be triggered and bring 562the heap usage down, therefore multiple snapshots may be written to disk 563before the Node.js instance finally runs out of memory. These heap snapshots 564can be compared to determine what objects are being allocated during the 565time consecutive snapshots are taken. It's not guaranteed that Node.js will 566write exactly <code>max_count</code> snapshots to disk, but it will try 567its best to generate at least one and up to <code>max_count</code> snapshots before the 568Node.js instance runs out of memory when <code>max_count</code> is greater than <code>0</code>.</p> 569<p>Generating V8 snapshots takes time and memory (both memory managed by the 570V8 heap and native memory outside the V8 heap). The bigger the heap is, 571the more resources it needs. Node.js will adjust the V8 heap to accommondate 572the additional V8 heap memory overhead, and try its best to avoid using up 573all the memory avialable to the process. When the process uses 574more memory than the system deems appropriate, the process may be terminated 575abruptly by the system, depending on the system configuration.</p> 576<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --max-old-space-size=100 --heapsnapshot-near-heap-limit=3 index.js</span> 577Wrote snapshot to Heap.20200430.100036.49580.0.001.heapsnapshot 578Wrote snapshot to Heap.20200430.100037.49580.0.002.heapsnapshot 579Wrote snapshot to Heap.20200430.100038.49580.0.003.heapsnapshot 580 581<--- Last few GCs ---> 582 583[49580:0x110000000] 4826 ms: Mark-sweep 130.6 (147.8) -> 130.5 (147.8) MB, 27.4 / 0.0 ms (average mu = 0.126, current mu = 0.034) allocation failure scavenge might not succeed 584[49580:0x110000000] 4845 ms: Mark-sweep 130.6 (147.8) -> 130.6 (147.8) MB, 18.8 / 0.0 ms (average mu = 0.088, current mu = 0.031) allocation failure scavenge might not succeed 585 586 587<--- JS stacktrace ---> 588 589FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory 590....</code></pre> 591<h4><code>--heapsnapshot-signal=signal</code><span><a class="mark" href="#cli_heapsnapshot_signal_signal" id="cli_heapsnapshot_signal_signal">#</a></span></h4> 592<div class="api_metadata"> 593<span>Added in: v12.0.0</span> 594</div> 595<p>Enables a signal handler that causes the Node.js process to write a heap dump 596when the specified signal is received. <code>signal</code> must be a valid signal name. 597Disabled by default.</p> 598<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --heapsnapshot-signal=SIGUSR2 index.js &</span> 599<span class="hljs-meta">$ </span><span class="language-bash">ps aux</span> 600USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND 601node 1 5.5 6.1 787252 247004 ? Ssl 16:43 0:02 node --heapsnapshot-signal=SIGUSR2 index.js 602<span class="hljs-meta">$ </span><span class="language-bash"><span class="hljs-built_in">kill</span> -USR2 1</span> 603<span class="hljs-meta">$ </span><span class="language-bash">ls</span> 604Heap.20190718.133405.15554.0.001.heapsnapshot</code></pre> 605<h4><code>--heap-prof</code><span><a class="mark" href="#cli_heap_prof" id="cli_heap_prof">#</a></span></h4> 606<div class="api_metadata"> 607<span>Added in: v12.4.0</span> 608</div> 609<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 610<p>Starts the V8 heap profiler on start up, and writes the heap profile to disk 611before exit.</p> 612<p>If <code>--heap-prof-dir</code> is not specified, the generated profile is placed 613in the current working directory.</p> 614<p>If <code>--heap-prof-name</code> is not specified, the generated profile is 615named <code>Heap.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.heapprofile</code>.</p> 616<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --heap-prof index.js</span> 617<span class="hljs-meta">$ </span><span class="language-bash">ls *.heapprofile</span> 618Heap.20190409.202950.15293.0.001.heapprofile</code></pre> 619<h4><code>--heap-prof-dir</code><span><a class="mark" href="#cli_heap_prof_dir" id="cli_heap_prof_dir">#</a></span></h4> 620<div class="api_metadata"> 621<span>Added in: v12.4.0</span> 622</div> 623<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 624<p>Specify the directory where the heap profiles generated by <code>--heap-prof</code> will 625be placed.</p> 626<p>The default value is controlled by the 627<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p> 628<h4><code>--heap-prof-interval</code><span><a class="mark" href="#cli_heap_prof_interval" id="cli_heap_prof_interval">#</a></span></h4> 629<div class="api_metadata"> 630<span>Added in: v12.4.0</span> 631</div> 632<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 633<p>Specify the average sampling interval in bytes for the heap profiles generated 634by <code>--heap-prof</code>. The default is 512 * 1024 bytes.</p> 635<h4><code>--heap-prof-name</code><span><a class="mark" href="#cli_heap_prof_name" id="cli_heap_prof_name">#</a></span></h4> 636<div class="api_metadata"> 637<span>Added in: v12.4.0</span> 638</div> 639<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 640<p>Specify the file name of the heap profile generated by <code>--heap-prof</code>.</p> 641<h4><code>--icu-data-dir=file</code><span><a class="mark" href="#cli_icu_data_dir_file" id="cli_icu_data_dir_file">#</a></span></h4> 642<div class="api_metadata"> 643<span>Added in: v0.11.15</span> 644</div> 645<p>Specify ICU data load path. (Overrides <code>NODE_ICU_DATA</code>.)</p> 646<h4><code>--input-type=type</code><span><a class="mark" href="#cli_input_type_type" id="cli_input_type_type">#</a></span></h4> 647<div class="api_metadata"> 648<span>Added in: v12.0.0</span> 649</div> 650<p>This configures Node.js to interpret string input as CommonJS or as an ES 651module. String input is input via <code>--eval</code>, <code>--print</code>, or <code>STDIN</code>.</p> 652<p>Valid values are <code>"commonjs"</code> and <code>"module"</code>. The default is <code>"commonjs"</code>.</p> 653<h4><code>--inspect-brk[=[host:]port]</code><span><a class="mark" href="#cli_inspect_brk_host_port" id="cli_inspect_brk_host_port">#</a></span></h4> 654<div class="api_metadata"> 655<span>Added in: v7.6.0</span> 656</div> 657<p>Activate inspector on <code>host:port</code> and break at start of user script. 658Default <code>host:port</code> is <code>127.0.0.1:9229</code>.</p> 659<h4><code>--inspect-port=[host:]port</code><span><a class="mark" href="#cli_inspect_port_host_port" id="cli_inspect_port_host_port">#</a></span></h4> 660<div class="api_metadata"> 661<span>Added in: v7.6.0</span> 662</div> 663<p>Set the <code>host:port</code> to be used when the inspector is activated. 664Useful when activating the inspector by sending the <code>SIGUSR1</code> signal.</p> 665<p>Default host is <code>127.0.0.1</code>.</p> 666<p>See the <a href="#inspector_security">security warning</a> below regarding the <code>host</code> 667parameter usage.</p> 668<h4><code>--inspect[=[host:]port]</code><span><a class="mark" href="#cli_inspect_host_port" id="cli_inspect_host_port">#</a></span></h4> 669<div class="api_metadata"> 670<span>Added in: v6.3.0</span> 671</div> 672<p>Activate inspector on <code>host:port</code>. Default is <code>127.0.0.1:9229</code>.</p> 673<p>V8 inspector integration allows tools such as Chrome DevTools and IDEs to debug 674and profile Node.js instances. The tools attach to Node.js instances via a 675tcp port and communicate using the <a href="https://chromedevtools.github.io/devtools-protocol/">Chrome DevTools Protocol</a>.</p> 676<p><a id="inspector_security"></a></p> 677<h5>Warning: binding inspector to a public IP:port combination is insecure<span><a class="mark" href="#cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure" id="cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure">#</a></span></h5> 678<p>Binding the inspector to a public IP (including <code>0.0.0.0</code>) with an open port is 679insecure, as it allows external hosts to connect to the inspector and perform 680a <a href="https://www.owasp.org/index.php/Code_Injection">remote code execution</a> attack.</p> 681<p>If specifying a host, make sure that either:</p> 682<ul> 683<li>The host is not accessible from public networks.</li> 684<li>A firewall disallows unwanted connections on the port.</li> 685</ul> 686<p><strong>More specifically, <code>--inspect=0.0.0.0</code> is insecure if the port (<code>9229</code> by 687default) is not firewall-protected.</strong></p> 688<p>See the <a href="https://nodejs.org/en/docs/guides/debugging-getting-started/#security-implications">debugging security implications</a> section for more information.</p> 689<h4><code>--inspect-publish-uid=stderr,http</code><span><a class="mark" href="#cli_inspect_publish_uid_stderr_http" id="cli_inspect_publish_uid_stderr_http">#</a></span></h4> 690<p>Specify ways of the inspector web socket url exposure.</p> 691<p>By default inspector websocket url is available in stderr and under <code>/json/list</code> 692endpoint on <code>http://host:port/json/list</code>.</p> 693<h4><code>--insecure-http-parser</code><span><a class="mark" href="#cli_insecure_http_parser" id="cli_insecure_http_parser">#</a></span></h4> 694<div class="api_metadata"> 695<span>Added in: v13.4.0, v12.15.0, v10.19.0</span> 696</div> 697<p>Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow 698interoperability with non-conformant HTTP implementations. It may also allow 699request smuggling and other HTTP attacks that rely on invalid headers being 700accepted. Avoid using this option.</p> 701<h4><code>--jitless</code><span><a class="mark" href="#cli_jitless" id="cli_jitless">#</a></span></h4> 702<div class="api_metadata"> 703<span>Added in: v12.0.0</span> 704</div> 705<p>Disable <a href="https://v8.dev/blog/jitless">runtime allocation of executable memory</a>. This may be 706required on some platforms for security reasons. It can also reduce attack 707surface on other platforms, but the performance impact may be severe.</p> 708<p>This flag is inherited from V8 and is subject to change upstream. It may 709disappear in a non-semver-major release.</p> 710<h4><code>--max-http-header-size=size</code><span><a class="mark" href="#cli_max_http_header_size_size" id="cli_max_http_header_size_size">#</a></span></h4> 711<div class="api_metadata"> 712<details class="changelog"><summary>History</summary> 713<table> 714<tbody><tr><th>Version</th><th>Changes</th></tr> 715<tr><td>v14.0.0</td> 716<td><p>Change maximum default size of HTTP headers from 8KB to 16KB.</p></td></tr> 717<tr><td>v11.6.0, v10.15.0</td> 718<td><p><span>Added in: v11.6.0, v10.15.0</span></p></td></tr> 719</tbody></table> 720</details> 721</div> 722<p>Specify the maximum size, in bytes, of HTTP headers. Defaults to 16KB.</p> 723<h4><code>--napi-modules</code><span><a class="mark" href="#cli_napi_modules" id="cli_napi_modules">#</a></span></h4> 724<div class="api_metadata"> 725<span>Added in: v7.10.0</span> 726</div> 727<p>This option is a no-op. It is kept for compatibility.</p> 728<h4><code>--no-addons</code><span><a class="mark" href="#cli_no_addons" id="cli_no_addons">#</a></span></h4> 729<div class="api_metadata"> 730<span>Added in: v14.19.0</span> 731</div> 732<p>Disable the <code>node-addons</code> exports condition as well as disable loading 733native addons. When <code>--no-addons</code> is specified, calling <code>process.dlopen</code> or 734requiring a native C++ addon will fail and throw an exception.</p> 735<h4><code>--no-deprecation</code><span><a class="mark" href="#cli_no_deprecation" id="cli_no_deprecation">#</a></span></h4> 736<div class="api_metadata"> 737<span>Added in: v0.8.0</span> 738</div> 739<p>Silence deprecation warnings.</p> 740<h4><code>--no-force-async-hooks-checks</code><span><a class="mark" href="#cli_no_force_async_hooks_checks" id="cli_no_force_async_hooks_checks">#</a></span></h4> 741<div class="api_metadata"> 742<span>Added in: v9.0.0</span> 743</div> 744<p>Disables runtime checks for <code>async_hooks</code>. These will still be enabled 745dynamically when <code>async_hooks</code> is enabled.</p> 746<h4><code>--no-warnings</code><span><a class="mark" href="#cli_no_warnings" id="cli_no_warnings">#</a></span></h4> 747<div class="api_metadata"> 748<span>Added in: v6.0.0</span> 749</div> 750<p>Silence all process warnings (including deprecations).</p> 751<h4><code>--node-memory-debug</code><span><a class="mark" href="#cli_node_memory_debug" id="cli_node_memory_debug">#</a></span></h4> 752<div class="api_metadata"> 753<span>Added in: v14.18.0</span> 754</div> 755<p>Enable extra debug checks for memory leaks in Node.js internals. This is 756usually only useful for developers debugging Node.js itself.</p> 757<h4><code>--openssl-config=file</code><span><a class="mark" href="#cli_openssl_config_file" id="cli_openssl_config_file">#</a></span></h4> 758<div class="api_metadata"> 759<span>Added in: v6.9.0</span> 760</div> 761<p>Load an OpenSSL configuration file on startup. Among other uses, this can be 762used to enable FIPS-compliant crypto if Node.js is built 763against FIPS-enabled OpenSSL.</p> 764<h4><code>--pending-deprecation</code><span><a class="mark" href="#cli_pending_deprecation" id="cli_pending_deprecation">#</a></span></h4> 765<div class="api_metadata"> 766<span>Added in: v8.0.0</span> 767</div> 768<p>Emit pending deprecation warnings.</p> 769<p>Pending deprecations are generally identical to a runtime deprecation with the 770notable exception that they are turned <em>off</em> by default and will not be emitted 771unless either the <code>--pending-deprecation</code> command-line flag, or the 772<code>NODE_PENDING_DEPRECATION=1</code> environment variable, is set. Pending deprecations 773are used to provide a kind of selective "early warning" mechanism that 774developers may leverage to detect deprecated API usage.</p> 775<h4><code>--policy-integrity=sri</code><span><a class="mark" href="#cli_policy_integrity_sri" id="cli_policy_integrity_sri">#</a></span></h4> 776<div class="api_metadata"> 777<span>Added in: v12.7.0</span> 778</div> 779<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 780<p>Instructs Node.js to error prior to running any code if the policy does not have 781the specified integrity. It expects a <a href="https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity">Subresource Integrity</a> string as a 782parameter.</p> 783<h4><code>--preserve-symlinks</code><span><a class="mark" href="#cli_preserve_symlinks" id="cli_preserve_symlinks">#</a></span></h4> 784<div class="api_metadata"> 785<span>Added in: v6.3.0</span> 786</div> 787<p>Instructs the module loader to preserve symbolic links when resolving and 788caching modules.</p> 789<p>By default, when Node.js loads a module from a path that is symbolically linked 790to a different on-disk location, Node.js will dereference the link and use the 791actual on-disk "real path" of the module as both an identifier and as a root 792path to locate other dependency modules. In most cases, this default behavior 793is acceptable. However, when using symbolically linked peer dependencies, as 794illustrated in the example below, the default behavior causes an exception to 795be thrown if <code>moduleA</code> attempts to require <code>moduleB</code> as a peer dependency:</p> 796<pre><code class="language-text">{appDir} 797 ├── app 798 │ ├── index.js 799 │ └── node_modules 800 │ ├── moduleA -> {appDir}/moduleA 801 │ └── moduleB 802 │ ├── index.js 803 │ └── package.json 804 └── moduleA 805 ├── index.js 806 └── package.json</code></pre> 807<p>The <code>--preserve-symlinks</code> command-line flag instructs Node.js to use the 808symlink path for modules as opposed to the real path, allowing symbolically 809linked peer dependencies to be found.</p> 810<p>Note, however, that using <code>--preserve-symlinks</code> can have other side effects. 811Specifically, symbolically linked <em>native</em> modules can fail to load if those 812are linked from more than one location in the dependency tree (Node.js would 813see those as two separate modules and would attempt to load the module multiple 814times, causing an exception to be thrown).</p> 815<p>The <code>--preserve-symlinks</code> flag does not apply to the main module, which allows 816<code>node --preserve-symlinks node_module/.bin/<foo></code> to work. To apply the same 817behavior for the main module, also use <code>--preserve-symlinks-main</code>.</p> 818<h4><code>--preserve-symlinks-main</code><span><a class="mark" href="#cli_preserve_symlinks_main" id="cli_preserve_symlinks_main">#</a></span></h4> 819<div class="api_metadata"> 820<span>Added in: v10.2.0</span> 821</div> 822<p>Instructs the module loader to preserve symbolic links when resolving and 823caching the main module (<code>require.main</code>).</p> 824<p>This flag exists so that the main module can be opted-in to the same behavior 825that <code>--preserve-symlinks</code> gives to all other imports; they are separate flags, 826however, for backward compatibility with older Node.js versions.</p> 827<p><code>--preserve-symlinks-main</code> does not imply <code>--preserve-symlinks</code>; use 828<code>--preserve-symlinks-main</code> in addition to 829<code>--preserve-symlinks</code> when it is not desirable to follow symlinks before 830resolving relative paths.</p> 831<p>See <code>--preserve-symlinks</code> for more information.</p> 832<h4><code>--prof</code><span><a class="mark" href="#cli_prof" id="cli_prof">#</a></span></h4> 833<div class="api_metadata"> 834<span>Added in: v2.0.0</span> 835</div> 836<p>Generate V8 profiler output.</p> 837<h4><code>--prof-process</code><span><a class="mark" href="#cli_prof_process" id="cli_prof_process">#</a></span></h4> 838<div class="api_metadata"> 839<span>Added in: v5.2.0</span> 840</div> 841<p>Process V8 profiler output generated using the V8 option <code>--prof</code>.</p> 842<h4><code>--redirect-warnings=file</code><span><a class="mark" href="#cli_redirect_warnings_file" id="cli_redirect_warnings_file">#</a></span></h4> 843<div class="api_metadata"> 844<span>Added in: v8.0.0</span> 845</div> 846<p>Write process warnings to the given file instead of printing to stderr. The 847file will be created if it does not exist, and will be appended to if it does. 848If an error occurs while attempting to write the warning to the file, the 849warning will be written to stderr instead.</p> 850<p>The <code>file</code> name may be an absolute path. If it is not, the default directory it 851will be written to is controlled by the 852<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p> 853<h4><code>--report-compact</code><span><a class="mark" href="#cli_report_compact" id="cli_report_compact">#</a></span></h4> 854<div class="api_metadata"> 855<span>Added in: v13.12.0</span> 856</div> 857<p>Write reports in a compact format, single-line JSON, more easily consumable 858by log processing systems than the default multi-line format designed for 859human consumption.</p> 860<h4><code>--report-dir=directory</code>, <code>report-directory=directory</code><span><a class="mark" href="#cli_report_dir_directory_report_directory_directory" id="cli_report_dir_directory_report_directory_directory">#</a></span></h4> 861<div class="api_metadata"> 862<details class="changelog"><summary>History</summary> 863<table> 864<tbody><tr><th>Version</th><th>Changes</th></tr> 865<tr><td>v13.12.0</td> 866<td><p>This option is no longer experimental.</p></td></tr> 867<tr><td>v12.0.0</td> 868<td><p>Changed from <code>--diagnostic-report-directory</code> to <code>--report-directory</code>.</p></td></tr> 869<tr><td>v11.8.0</td> 870<td><p><span>Added in: v11.8.0</span></p></td></tr> 871</tbody></table> 872</details> 873</div> 874<p>Location at which the report will be generated.</p> 875<h4><code>--report-filename=filename</code><span><a class="mark" href="#cli_report_filename_filename" id="cli_report_filename_filename">#</a></span></h4> 876<div class="api_metadata"> 877<details class="changelog"><summary>History</summary> 878<table> 879<tbody><tr><th>Version</th><th>Changes</th></tr> 880<tr><td>v13.12.0</td> 881<td><p>This option is no longer experimental.</p></td></tr> 882<tr><td>v12.0.0</td> 883<td><p>changed from <code>--diagnostic-report-filename</code> to <code>--report-filename</code>.</p></td></tr> 884<tr><td>v11.8.0</td> 885<td><p><span>Added in: v11.8.0</span></p></td></tr> 886</tbody></table> 887</details> 888</div> 889<p>Name of the file to which the report will be written.</p> 890<h4><code>--report-on-fatalerror</code><span><a class="mark" href="#cli_report_on_fatalerror" id="cli_report_on_fatalerror">#</a></span></h4> 891<div class="api_metadata"> 892<details class="changelog"><summary>History</summary> 893<table> 894<tbody><tr><th>Version</th><th>Changes</th></tr> 895<tr><td>v14.0.0</td> 896<td><p>This option is no longer experimental.</p></td></tr> 897<tr><td>v12.0.0</td> 898<td><p>changed from <code>--diagnostic-report-on-fatalerror</code> to <code>--report-on-fatalerror</code>.</p></td></tr> 899<tr><td>v11.8.0</td> 900<td><p><span>Added in: v11.8.0</span></p></td></tr> 901</tbody></table> 902</details> 903</div> 904<p>Enables the report to be triggered on fatal errors (internal errors within 905the Node.js runtime such as out of memory) that lead to termination of the 906application. Useful to inspect various diagnostic data elements such as heap, 907stack, event loop state, resource consumption etc. to reason about the fatal 908error.</p> 909<h4><code>--report-on-signal</code><span><a class="mark" href="#cli_report_on_signal" id="cli_report_on_signal">#</a></span></h4> 910<div class="api_metadata"> 911<details class="changelog"><summary>History</summary> 912<table> 913<tbody><tr><th>Version</th><th>Changes</th></tr> 914<tr><td>v13.12.0</td> 915<td><p>This option is no longer experimental.</p></td></tr> 916<tr><td>v12.0.0</td> 917<td><p>changed from <code>--diagnostic-report-on-signal</code> to <code>--report-on-signal</code>.</p></td></tr> 918<tr><td>v11.8.0</td> 919<td><p><span>Added in: v11.8.0</span></p></td></tr> 920</tbody></table> 921</details> 922</div> 923<p>Enables report to be generated upon receiving the specified (or predefined) 924signal to the running Node.js process. The signal to trigger the report is 925specified through <code>--report-signal</code>.</p> 926<h4><code>--report-signal=signal</code><span><a class="mark" href="#cli_report_signal_signal" id="cli_report_signal_signal">#</a></span></h4> 927<div class="api_metadata"> 928<details class="changelog"><summary>History</summary> 929<table> 930<tbody><tr><th>Version</th><th>Changes</th></tr> 931<tr><td>v13.12.0</td> 932<td><p>This option is no longer experimental.</p></td></tr> 933<tr><td>v12.0.0</td> 934<td><p>changed from <code>--diagnostic-report-signal</code> to <code>--report-signal</code>.</p></td></tr> 935<tr><td>v11.8.0</td> 936<td><p><span>Added in: v11.8.0</span></p></td></tr> 937</tbody></table> 938</details> 939</div> 940<p>Sets or resets the signal for report generation (not supported on Windows). 941Default signal is <code>SIGUSR2</code>.</p> 942<h4><code>--report-uncaught-exception</code><span><a class="mark" href="#cli_report_uncaught_exception" id="cli_report_uncaught_exception">#</a></span></h4> 943<div class="api_metadata"> 944<details class="changelog"><summary>History</summary> 945<table> 946<tbody><tr><th>Version</th><th>Changes</th></tr> 947<tr><td>v13.12.0</td> 948<td><p>This option is no longer experimental.</p></td></tr> 949<tr><td>v12.0.0</td> 950<td><p>changed from <code>--diagnostic-report-uncaught-exception</code> to <code>--report-uncaught-exception</code>.</p></td></tr> 951<tr><td>v11.8.0</td> 952<td><p><span>Added in: v11.8.0</span></p></td></tr> 953</tbody></table> 954</details> 955</div> 956<p>Enables report to be generated on uncaught exceptions. Useful when inspecting 957the JavaScript stack in conjunction with native stack and other runtime 958environment data.</p> 959<h4><code>--throw-deprecation</code><span><a class="mark" href="#cli_throw_deprecation" id="cli_throw_deprecation">#</a></span></h4> 960<div class="api_metadata"> 961<span>Added in: v0.11.14</span> 962</div> 963<p>Throw errors for deprecations.</p> 964<h4><code>--title=title</code><span><a class="mark" href="#cli_title_title" id="cli_title_title">#</a></span></h4> 965<div class="api_metadata"> 966<span>Added in: v10.7.0</span> 967</div> 968<p>Set <code>process.title</code> on startup.</p> 969<h4><code>--tls-cipher-list=list</code><span><a class="mark" href="#cli_tls_cipher_list_list" id="cli_tls_cipher_list_list">#</a></span></h4> 970<div class="api_metadata"> 971<span>Added in: v4.0.0</span> 972</div> 973<p>Specify an alternative default TLS cipher list. Requires Node.js to be built 974with crypto support (default).</p> 975<h4><code>--tls-keylog=file</code><span><a class="mark" href="#cli_tls_keylog_file" id="cli_tls_keylog_file">#</a></span></h4> 976<div class="api_metadata"> 977<span>Added in: v13.2.0, v12.16.0</span> 978</div> 979<p>Log TLS key material to a file. The key material is in NSS <code>SSLKEYLOGFILE</code> 980format and can be used by software (such as Wireshark) to decrypt the TLS 981traffic.</p> 982<h4><code>--tls-max-v1.2</code><span><a class="mark" href="#cli_tls_max_v1_2" id="cli_tls_max_v1_2">#</a></span></h4> 983<div class="api_metadata"> 984<span>Added in: v12.0.0, v10.20.0</span> 985</div> 986<p>Set <a href="tls.html#tls_tls_default_max_version"><code>tls.DEFAULT_MAX_VERSION</code></a> to 'TLSv1.2'. Use to disable support for 987TLSv1.3.</p> 988<h4><code>--tls-max-v1.3</code><span><a class="mark" href="#cli_tls_max_v1_3" id="cli_tls_max_v1_3">#</a></span></h4> 989<div class="api_metadata"> 990<span>Added in: v12.0.0</span> 991</div> 992<p>Set default <a href="tls.html#tls_tls_default_max_version"><code>tls.DEFAULT_MAX_VERSION</code></a> to 'TLSv1.3'. Use to enable support 993for TLSv1.3.</p> 994<h4><code>--tls-min-v1.0</code><span><a class="mark" href="#cli_tls_min_v1_0" id="cli_tls_min_v1_0">#</a></span></h4> 995<div class="api_metadata"> 996<span>Added in: v12.0.0, v10.20.0</span> 997</div> 998<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1'. Use for compatibility with 999old TLS clients or servers.</p> 1000<h4><code>--tls-min-v1.1</code><span><a class="mark" href="#cli_tls_min_v1_1" id="cli_tls_min_v1_1">#</a></span></h4> 1001<div class="api_metadata"> 1002<span>Added in: v12.0.0, v10.20.0</span> 1003</div> 1004<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.1'. Use for compatibility 1005with old TLS clients or servers.</p> 1006<h4><code>--tls-min-v1.2</code><span><a class="mark" href="#cli_tls_min_v1_2" id="cli_tls_min_v1_2">#</a></span></h4> 1007<div class="api_metadata"> 1008<span>Added in: v12.2.0, v10.20.0</span> 1009</div> 1010<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.2'. This is the default for 101112.x and later, but the option is supported for compatibility with older Node.js 1012versions.</p> 1013<h4><code>--tls-min-v1.3</code><span><a class="mark" href="#cli_tls_min_v1_3" id="cli_tls_min_v1_3">#</a></span></h4> 1014<div class="api_metadata"> 1015<span>Added in: v12.0.0</span> 1016</div> 1017<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.3'. Use to disable support 1018for TLSv1.2, which is not as secure as TLSv1.3.</p> 1019<h4><code>--trace-atomics-wait</code><span><a class="mark" href="#cli_trace_atomics_wait" id="cli_trace_atomics_wait">#</a></span></h4> 1020<div class="api_metadata"> 1021<span>Added in: v14.3.0</span> 1022</div> 1023<p>Print short summaries of calls to <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/wait"><code>Atomics.wait()</code></a> to stderr. 1024The output could look like this:</p> 1025<pre><code class="language-text">(node:15701) [Thread 0] Atomics.wait(&lt;address> + 0, 1, inf) started 1026(node:15701) [Thread 0] Atomics.wait(&lt;address> + 0, 1, inf) did not wait because the values mismatched 1027(node:15701) [Thread 0] Atomics.wait(&lt;address> + 0, 0, 10) started 1028(node:15701) [Thread 0] Atomics.wait(&lt;address> + 0, 0, 10) timed out 1029(node:15701) [Thread 0] Atomics.wait(&lt;address> + 4, 0, inf) started 1030(node:15701) [Thread 1] Atomics.wait(&lt;address> + 4, -1, inf) started 1031(node:15701) [Thread 0] Atomics.wait(&lt;address> + 4, 0, inf) was woken up by another thread 1032(node:15701) [Thread 1] Atomics.wait(&lt;address> + 4, -1, inf) was woken up by another thread</code></pre> 1033<p>The fields here correspond to:</p> 1034<ul> 1035<li>The thread id as given by <a href="worker_threads.html#worker_threads_worker_threadid"><code>worker_threads.threadId</code></a></li> 1036<li>The base address of the <code>SharedArrayBuffer</code> in question, as well as the 1037byte offset corresponding to the index passed to <code>Atomics.wait()</code></li> 1038<li>The expected value that was passed to <code>Atomics.wait()</code></li> 1039<li>The timeout passed to <code>Atomics.wait</code></li> 1040</ul> 1041<h4><code>--trace-deprecation</code><span><a class="mark" href="#cli_trace_deprecation" id="cli_trace_deprecation">#</a></span></h4> 1042<div class="api_metadata"> 1043<span>Added in: v0.8.0</span> 1044</div> 1045<p>Print stack traces for deprecations.</p> 1046<h4><code>--trace-event-categories</code><span><a class="mark" href="#cli_trace_event_categories" id="cli_trace_event_categories">#</a></span></h4> 1047<div class="api_metadata"> 1048<span>Added in: v7.7.0</span> 1049</div> 1050<p>A comma separated list of categories that should be traced when trace event 1051tracing is enabled using <code>--trace-events-enabled</code>.</p> 1052<h4><code>--trace-event-file-pattern</code><span><a class="mark" href="#cli_trace_event_file_pattern" id="cli_trace_event_file_pattern">#</a></span></h4> 1053<div class="api_metadata"> 1054<span>Added in: v9.8.0</span> 1055</div> 1056<p>Template string specifying the filepath for the trace event data, it 1057supports <code>${rotation}</code> and <code>${pid}</code>.</p> 1058<h4><code>--trace-events-enabled</code><span><a class="mark" href="#cli_trace_events_enabled" id="cli_trace_events_enabled">#</a></span></h4> 1059<div class="api_metadata"> 1060<span>Added in: v7.7.0</span> 1061</div> 1062<p>Enables the collection of trace event tracing information.</p> 1063<h4><code>--trace-exit</code><span><a class="mark" href="#cli_trace_exit" id="cli_trace_exit">#</a></span></h4> 1064<div class="api_metadata"> 1065<span>Added in: v13.5.0, v12.16.0</span> 1066</div> 1067<p>Prints a stack trace whenever an environment is exited proactively, 1068i.e. invoking <code>process.exit()</code>.</p> 1069<h4><code>--trace-sigint</code><span><a class="mark" href="#cli_trace_sigint" id="cli_trace_sigint">#</a></span></h4> 1070<div class="api_metadata"> 1071<span>Added in: v13.9.0</span> 1072</div> 1073<p>Prints a stack trace on SIGINT.</p> 1074<h4><code>--trace-sync-io</code><span><a class="mark" href="#cli_trace_sync_io" id="cli_trace_sync_io">#</a></span></h4> 1075<div class="api_metadata"> 1076<span>Added in: v2.1.0</span> 1077</div> 1078<p>Prints a stack trace whenever synchronous I/O is detected after the first turn 1079of the event loop.</p> 1080<h4><code>--trace-tls</code><span><a class="mark" href="#cli_trace_tls" id="cli_trace_tls">#</a></span></h4> 1081<div class="api_metadata"> 1082<span>Added in: v12.2.0</span> 1083</div> 1084<p>Prints TLS packet trace information to <code>stderr</code>. This can be used to debug TLS 1085connection problems.</p> 1086<h4><code>--trace-uncaught</code><span><a class="mark" href="#cli_trace_uncaught" id="cli_trace_uncaught">#</a></span></h4> 1087<div class="api_metadata"> 1088<span>Added in: v13.1.0</span> 1089</div> 1090<p>Print stack traces for uncaught exceptions; usually, the stack trace associated 1091with the creation of an <code>Error</code> is printed, whereas this makes Node.js also 1092print the stack trace associated with throwing the value (which does not need 1093to be an <code>Error</code> instance).</p> 1094<p>Enabling this option may affect garbage collection behavior negatively.</p> 1095<h4><code>--trace-warnings</code><span><a class="mark" href="#cli_trace_warnings" id="cli_trace_warnings">#</a></span></h4> 1096<div class="api_metadata"> 1097<span>Added in: v6.0.0</span> 1098</div> 1099<p>Print stack traces for process warnings (including deprecations).</p> 1100<h4><code>--track-heap-objects</code><span><a class="mark" href="#cli_track_heap_objects" id="cli_track_heap_objects">#</a></span></h4> 1101<div class="api_metadata"> 1102<span>Added in: v2.4.0</span> 1103</div> 1104<p>Track heap object allocations for heap snapshots.</p> 1105<h4><code>--unhandled-rejections=mode</code><span><a class="mark" href="#cli_unhandled_rejections_mode" id="cli_unhandled_rejections_mode">#</a></span></h4> 1106<div class="api_metadata"> 1107<span>Added in: v12.0.0, v10.17.0</span> 1108</div> 1109<p>By default all unhandled rejections trigger a warning plus a deprecation warning 1110for the very first unhandled rejection in case no <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a> hook 1111is used.</p> 1112<p>Using this flag allows to change what should happen when an unhandled rejection 1113occurs. One of the following modes can be chosen:</p> 1114<ul> 1115<li><code>throw</code>: Emit <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a>. If this hook is not set, raise the 1116unhandled rejection as an uncaught exception.</li> 1117<li><code>strict</code>: Raise the unhandled rejection as an uncaught exception.</li> 1118<li><code>warn</code>: Always trigger a warning, no matter if the <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a> 1119hook is set or not but do not print the deprecation warning.</li> 1120<li><code>warn-with-error-code</code>: Emit <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a>. If this hook is not 1121set, trigger a warning, and set the process exit code to 1.</li> 1122<li><code>none</code>: Silence all warnings.</li> 1123</ul> 1124<h4><code>--use-bundled-ca</code>, <code>--use-openssl-ca</code><span><a class="mark" href="#cli_use_bundled_ca_use_openssl_ca" id="cli_use_bundled_ca_use_openssl_ca">#</a></span></h4> 1125<div class="api_metadata"> 1126<span>Added in: v6.11.0</span> 1127</div> 1128<p>Use bundled Mozilla CA store as supplied by current Node.js version 1129or use OpenSSL's default CA store. The default store is selectable 1130at build-time.</p> 1131<p>The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store 1132that is fixed at release time. It is identical on all supported platforms.</p> 1133<p>Using OpenSSL store allows for external modifications of the store. For most 1134Linux and BSD distributions, this store is maintained by the distribution 1135maintainers and system administrators. OpenSSL CA store location is dependent on 1136configuration of the OpenSSL library but this can be altered at runtime using 1137environment variables.</p> 1138<p>See <code>SSL_CERT_DIR</code> and <code>SSL_CERT_FILE</code>.</p> 1139<h4><code>--use-largepages=mode</code><span><a class="mark" href="#cli_use_largepages_mode" id="cli_use_largepages_mode">#</a></span></h4> 1140<div class="api_metadata"> 1141<span>Added in: v13.6.0</span> 1142</div> 1143<p>Re-map the Node.js static code to large memory pages at startup. If supported on 1144the target system, this will cause the Node.js static code to be moved onto 2 1145MiB pages instead of 4 KiB pages.</p> 1146<p>The following values are valid for <code>mode</code>:</p> 1147<ul> 1148<li><code>off</code>: No mapping will be attempted. This is the default.</li> 1149<li><code>on</code>: If supported by the OS, mapping will be attempted. Failure to map will 1150be ignored and a message will be printed to standard error.</li> 1151<li><code>silent</code>: If supported by the OS, mapping will be attempted. Failure to map 1152will be ignored and will not be reported.</li> 1153</ul> 1154<h4><code>--v8-options</code><span><a class="mark" href="#cli_v8_options" id="cli_v8_options">#</a></span></h4> 1155<div class="api_metadata"> 1156<span>Added in: v0.1.3</span> 1157</div> 1158<p>Print V8 command-line options.</p> 1159<h4><code>--v8-pool-size=num</code><span><a class="mark" href="#cli_v8_pool_size_num" id="cli_v8_pool_size_num">#</a></span></h4> 1160<div class="api_metadata"> 1161<span>Added in: v5.10.0</span> 1162</div> 1163<p>Set V8's thread pool size which will be used to allocate background jobs.</p> 1164<p>If set to <code>0</code> then V8 will choose an appropriate size of the thread pool based 1165on the number of online processors.</p> 1166<p>If the value provided is larger than V8's maximum, then the largest value 1167will be chosen.</p> 1168<h4><code>--zero-fill-buffers</code><span><a class="mark" href="#cli_zero_fill_buffers" id="cli_zero_fill_buffers">#</a></span></h4> 1169<div class="api_metadata"> 1170<span>Added in: v6.0.0</span> 1171</div> 1172<p>Automatically zero-fills all newly allocated <a href="buffer.html#buffer_class_buffer"><code>Buffer</code></a> and <a href="buffer.html#buffer_class_slowbuffer"><code>SlowBuffer</code></a> 1173instances.</p> 1174<h4><code>-c</code>, <code>--check</code><span><a class="mark" href="#cli_c_check" id="cli_c_check">#</a></span></h4> 1175<div class="api_metadata"> 1176<details class="changelog"><summary>History</summary> 1177<table> 1178<tbody><tr><th>Version</th><th>Changes</th></tr> 1179<tr><td>v10.0.0</td> 1180<td><p>The <code>--require</code> option is now supported when checking a file.</p></td></tr> 1181<tr><td>v5.0.0, v4.2.0</td> 1182<td><p><span>Added in: v5.0.0, v4.2.0</span></p></td></tr> 1183</tbody></table> 1184</details> 1185</div> 1186<p>Syntax check the script without executing.</p> 1187<h4><code>-e</code>, <code>--eval "script"</code><span><a class="mark" href="#cli_e_eval_script" id="cli_e_eval_script">#</a></span></h4> 1188<div class="api_metadata"> 1189<details class="changelog"><summary>History</summary> 1190<table> 1191<tbody><tr><th>Version</th><th>Changes</th></tr> 1192<tr><td>v5.11.0</td> 1193<td><p>Built-in libraries are now available as predefined variables.</p></td></tr> 1194<tr><td>v0.5.2</td> 1195<td><p><span>Added in: v0.5.2</span></p></td></tr> 1196</tbody></table> 1197</details> 1198</div> 1199<p>Evaluate the following argument as JavaScript. The modules which are 1200predefined in the REPL can also be used in <code>script</code>.</p> 1201<p>On Windows, using <code>cmd.exe</code> a single quote will not work correctly because it 1202only recognizes double <code>"</code> for quoting. In Powershell or Git bash, both <code>'</code> 1203and <code>"</code> are usable.</p> 1204<h4><code>-h</code>, <code>--help</code><span><a class="mark" href="#cli_h_help" id="cli_h_help">#</a></span></h4> 1205<div class="api_metadata"> 1206<span>Added in: v0.1.3</span> 1207</div> 1208<p>Print node command-line options. 1209The output of this option is less detailed than this document.</p> 1210<h4><code>-i</code>, <code>--interactive</code><span><a class="mark" href="#cli_i_interactive" id="cli_i_interactive">#</a></span></h4> 1211<div class="api_metadata"> 1212<span>Added in: v0.7.7</span> 1213</div> 1214<p>Opens the REPL even if stdin does not appear to be a terminal.</p> 1215<h4><code>-p</code>, <code>--print "script"</code><span><a class="mark" href="#cli_p_print_script" id="cli_p_print_script">#</a></span></h4> 1216<div class="api_metadata"> 1217<details class="changelog"><summary>History</summary> 1218<table> 1219<tbody><tr><th>Version</th><th>Changes</th></tr> 1220<tr><td>v5.11.0</td> 1221<td><p>Built-in libraries are now available as predefined variables.</p></td></tr> 1222<tr><td>v0.6.4</td> 1223<td><p><span>Added in: v0.6.4</span></p></td></tr> 1224</tbody></table> 1225</details> 1226</div> 1227<p>Identical to <code>-e</code> but prints the result.</p> 1228<h4><code>-r</code>, <code>--require module</code><span><a class="mark" href="#cli_r_require_module" id="cli_r_require_module">#</a></span></h4> 1229<div class="api_metadata"> 1230<span>Added in: v1.6.0</span> 1231</div> 1232<p>Preload the specified module at startup.</p> 1233<p>Follows <code>require()</code>'s module resolution 1234rules. <code>module</code> may be either a path to a file, or a node module name.</p> 1235<p>Only CommonJS modules are supported. Attempting to preload a 1236ES6 Module using <code>--require</code> will fail with an error.</p> 1237<h4><code>-v</code>, <code>--version</code><span><a class="mark" href="#cli_v_version" id="cli_v_version">#</a></span></h4> 1238<div class="api_metadata"> 1239<span>Added in: v0.1.3</span> 1240</div> 1241<p>Print node's version.</p> 1242</section><section><h3>Environment variables<span><a class="mark" href="#cli_environment_variables" id="cli_environment_variables">#</a></span></h3> 1243<h4><code>FORCE_COLOR=[1, 2, 3]</code><span><a class="mark" href="#cli_force_color_1_2_3" id="cli_force_color_1_2_3">#</a></span></h4> 1244<p>The <code>FORCE_COLOR</code> environment variable is used to 1245enable ANSI colorized output. The value may be:</p> 1246<ul> 1247<li><code>1</code>, <code>true</code>, or the empty string <code>''</code> indicate 16-color support,</li> 1248<li><code>2</code> to indicate 256-color support, or</li> 1249<li><code>3</code> to indicate 16 million-color support.</li> 1250</ul> 1251<p>When <code>FORCE_COLOR</code> is used and set to a supported value, both the <code>NO_COLOR</code>, 1252and <code>NODE_DISABLE_COLORS</code> environment variables are ignored.</p> 1253<p>Any other value will result in colorized output being disabled.</p> 1254<h4><code>NODE_DEBUG=module[,…]</code><span><a class="mark" href="#cli_node_debug_module" id="cli_node_debug_module">#</a></span></h4> 1255<div class="api_metadata"> 1256<span>Added in: v0.1.32</span> 1257</div> 1258<p><code>','</code>-separated list of core modules that should print debug information.</p> 1259<h4><code>NODE_DEBUG_NATIVE=module[,…]</code><span><a class="mark" href="#cli_node_debug_native_module" id="cli_node_debug_native_module">#</a></span></h4> 1260<p><code>','</code>-separated list of core C++ modules that should print debug information.</p> 1261<h4><code>NODE_DISABLE_COLORS=1</code><span><a class="mark" href="#cli_node_disable_colors_1" id="cli_node_disable_colors_1">#</a></span></h4> 1262<div class="api_metadata"> 1263<span>Added in: v0.3.0</span> 1264</div> 1265<p>When set, colors will not be used in the REPL.</p> 1266<h4><code>NODE_EXTRA_CA_CERTS=file</code><span><a class="mark" href="#cli_node_extra_ca_certs_file" id="cli_node_extra_ca_certs_file">#</a></span></h4> 1267<div class="api_metadata"> 1268<span>Added in: v7.3.0</span> 1269</div> 1270<p>When set, the well known "root" CAs (like VeriSign) will be extended with the 1271extra certificates in <code>file</code>. The file should consist of one or more trusted 1272certificates in PEM format. A message will be emitted (once) with 1273<a href="process.html#process_process_emitwarning_warning_type_code_ctor"><code>process.emitWarning()</code></a> if the file is missing or 1274malformed, but any errors are otherwise ignored.</p> 1275<p>Neither the well known nor extra certificates are used when the <code>ca</code> 1276options property is explicitly specified for a TLS or HTTPS client or server.</p> 1277<p>This environment variable is ignored when <code>node</code> runs as setuid root or 1278has Linux file capabilities set.</p> 1279<p>The <code>NODE_EXTRA_CA_CERTS</code> environment variable is only read when the Node.js 1280process is first launched. Changing the value at runtime using 1281<code>process.env.NODE_EXTRA_CA_CERTS</code> has no effect on the current process.</p> 1282<h4><code>NODE_ICU_DATA=file</code><span><a class="mark" href="#cli_node_icu_data_file" id="cli_node_icu_data_file">#</a></span></h4> 1283<div class="api_metadata"> 1284<span>Added in: v0.11.15</span> 1285</div> 1286<p>Data path for ICU (<code>Intl</code> object) data. Will extend linked-in data when compiled 1287with small-icu support.</p> 1288<h4><code>NODE_NO_WARNINGS=1</code><span><a class="mark" href="#cli_node_no_warnings_1" id="cli_node_no_warnings_1">#</a></span></h4> 1289<div class="api_metadata"> 1290<span>Added in: v6.11.0</span> 1291</div> 1292<p>When set to <code>1</code>, process warnings are silenced.</p> 1293<h4><code>NODE_OPTIONS=options...</code><span><a class="mark" href="#cli_node_options_options" id="cli_node_options_options">#</a></span></h4> 1294<div class="api_metadata"> 1295<span>Added in: v8.0.0</span> 1296</div> 1297<p>A space-separated list of command-line options. <code>options...</code> are interpreted 1298before command-line options, so command-line options will override or 1299compound after anything in <code>options...</code>. Node.js will exit with an error if 1300an option that is not allowed in the environment is used, such as <code>-p</code> or a 1301script file.</p> 1302<p>If an option value contains a space, it can be escaped using double quotes:</p> 1303<pre><code class="language-bash">NODE_OPTIONS=<span class="hljs-string">'--require "./my path/file.js"'</span></code></pre> 1304<p>A singleton flag passed as a command-line option will override the same flag 1305passed into <code>NODE_OPTIONS</code>:</p> 1306<pre><code class="language-bash"><span class="hljs-comment"># The inspector will be available on port 5555</span> 1307NODE_OPTIONS=<span class="hljs-string">'--inspect=localhost:4444'</span> node --inspect=localhost:5555</code></pre> 1308<p>A flag that can be passed multiple times will be treated as if its 1309<code>NODE_OPTIONS</code> instances were passed first, and then its command-line 1310instances afterwards:</p> 1311<pre><code class="language-bash">NODE_OPTIONS=<span class="hljs-string">'--require "./a.js"'</span> node --require <span class="hljs-string">"./b.js"</span> 1312<span class="hljs-comment"># is equivalent to:</span> 1313node --require <span class="hljs-string">"./a.js"</span> --require <span class="hljs-string">"./b.js"</span></code></pre> 1314<p>Node.js options that are allowed are:</p> 1315<!-- node-options-node start --> 1316<ul> 1317<li><code>--conditions</code>, <code>-C</code></li> 1318<li><code>--diagnostic-dir</code></li> 1319<li><code>--disable-proto</code></li> 1320<li><code>--dns-result-order</code></li> 1321<li><code>--enable-fips</code></li> 1322<li><code>--enable-source-maps</code></li> 1323<li><code>--experimental-abortcontroller</code></li> 1324<li><code>--experimental-import-meta-resolve</code></li> 1325<li><code>--experimental-json-modules</code></li> 1326<li><code>--experimental-loader</code></li> 1327<li><code>--experimental-modules</code></li> 1328<li><code>--experimental-policy</code></li> 1329<li><code>--experimental-repl-await</code></li> 1330<li><code>--experimental-specifier-resolution</code></li> 1331<li><code>--experimental-top-level-await</code></li> 1332<li><code>--experimental-vm-modules</code></li> 1333<li><code>--experimental-wasi-unstable-preview1</code></li> 1334<li><code>--experimental-wasm-modules</code></li> 1335<li><code>--force-context-aware</code></li> 1336<li><code>--force-fips</code></li> 1337<li><code>--frozen-intrinsics</code></li> 1338<li><code>--heapsnapshot-near-heap-limit</code></li> 1339<li><code>--heapsnapshot-signal</code></li> 1340<li><code>--http-parser</code></li> 1341<li><code>--icu-data-dir</code></li> 1342<li><code>--input-type</code></li> 1343<li><code>--insecure-http-parser</code></li> 1344<li><code>--inspect-brk</code></li> 1345<li><code>--inspect-port</code>, <code>--debug-port</code></li> 1346<li><code>--inspect-publish-uid</code></li> 1347<li><code>--inspect</code></li> 1348<li><code>--max-http-header-size</code></li> 1349<li><code>--napi-modules</code></li> 1350<li><code>--no-addons</code></li> 1351<li><code>--no-deprecation</code></li> 1352<li><code>--no-force-async-hooks-checks</code></li> 1353<li><code>--no-warnings</code></li> 1354<li><code>--node-memory-debug</code></li> 1355<li><code>--openssl-config</code></li> 1356<li><code>--pending-deprecation</code></li> 1357<li><code>--policy-integrity</code></li> 1358<li><code>--preserve-symlinks-main</code></li> 1359<li><code>--preserve-symlinks</code></li> 1360<li><code>--prof-process</code></li> 1361<li><code>--redirect-warnings</code></li> 1362<li><code>--report-compact</code></li> 1363<li><code>--report-dir</code>, <code>--report-directory</code></li> 1364<li><code>--report-filename</code></li> 1365<li><code>--report-on-fatalerror</code></li> 1366<li><code>--report-on-signal</code></li> 1367<li><code>--report-signal</code></li> 1368<li><code>--report-uncaught-exception</code></li> 1369<li><code>--require</code>, <code>-r</code></li> 1370<li><code>--throw-deprecation</code></li> 1371<li><code>--title</code></li> 1372<li><code>--tls-cipher-list</code></li> 1373<li><code>--tls-keylog</code></li> 1374<li><code>--tls-max-v1.2</code></li> 1375<li><code>--tls-max-v1.3</code></li> 1376<li><code>--tls-min-v1.0</code></li> 1377<li><code>--tls-min-v1.1</code></li> 1378<li><code>--tls-min-v1.2</code></li> 1379<li><code>--tls-min-v1.3</code></li> 1380<li><code>--trace-atomics-wait</code></li> 1381<li><code>--trace-deprecation</code></li> 1382<li><code>--trace-event-categories</code></li> 1383<li><code>--trace-event-file-pattern</code></li> 1384<li><code>--trace-events-enabled</code></li> 1385<li><code>--trace-exit</code></li> 1386<li><code>--trace-sigint</code></li> 1387<li><code>--trace-sync-io</code></li> 1388<li><code>--trace-tls</code></li> 1389<li><code>--trace-uncaught</code></li> 1390<li><code>--trace-warnings</code></li> 1391<li><code>--track-heap-objects</code></li> 1392<li><code>--unhandled-rejections</code></li> 1393<li><code>--use-bundled-ca</code></li> 1394<li><code>--use-largepages</code></li> 1395<li><code>--use-openssl-ca</code></li> 1396<li><code>--v8-pool-size</code></li> 1397<li><code>--zero-fill-buffers</code></li> 1398</ul> 1399<!-- node-options-node end --> 1400<p>V8 options that are allowed are:</p> 1401<!-- node-options-v8 start --> 1402<ul> 1403<li><code>--abort-on-uncaught-exception</code></li> 1404<li><code>--disallow-code-generation-from-strings</code></li> 1405<li><code>--huge-max-old-generation-size</code></li> 1406<li><code>--interpreted-frames-native-stack</code></li> 1407<li><code>--jitless</code></li> 1408<li><code>--max-old-space-size</code></li> 1409<li><code>--perf-basic-prof-only-functions</code></li> 1410<li><code>--perf-basic-prof</code></li> 1411<li><code>--perf-prof-unwinding-info</code></li> 1412<li><code>--perf-prof</code></li> 1413<li><code>--stack-trace-limit</code></li> 1414</ul> 1415<!-- node-options-v8 end --> 1416<p><code>--perf-basic-prof-only-functions</code>, <code>--perf-basic-prof</code>, 1417<code>--perf-prof-unwinding-info</code>, and <code>--perf-prof</code> are only available on Linux.</p> 1418<h4><code>NODE_PATH=path[:…]</code><span><a class="mark" href="#cli_node_path_path" id="cli_node_path_path">#</a></span></h4> 1419<div class="api_metadata"> 1420<span>Added in: v0.1.32</span> 1421</div> 1422<p><code>':'</code>-separated list of directories prefixed to the module search path.</p> 1423<p>On Windows, this is a <code>';'</code>-separated list instead.</p> 1424<h4><code>NODE_PENDING_DEPRECATION=1</code><span><a class="mark" href="#cli_node_pending_deprecation_1" id="cli_node_pending_deprecation_1">#</a></span></h4> 1425<div class="api_metadata"> 1426<span>Added in: v8.0.0</span> 1427</div> 1428<p>When set to <code>1</code>, emit pending deprecation warnings.</p> 1429<p>Pending deprecations are generally identical to a runtime deprecation with the 1430notable exception that they are turned <em>off</em> by default and will not be emitted 1431unless either the <code>--pending-deprecation</code> command-line flag, or the 1432<code>NODE_PENDING_DEPRECATION=1</code> environment variable, is set. Pending deprecations 1433are used to provide a kind of selective "early warning" mechanism that 1434developers may leverage to detect deprecated API usage.</p> 1435<h4><code>NODE_PENDING_PIPE_INSTANCES=instances</code><span><a class="mark" href="#cli_node_pending_pipe_instances_instances" id="cli_node_pending_pipe_instances_instances">#</a></span></h4> 1436<p>Set the number of pending pipe instance handles when the pipe server is waiting 1437for connections. This setting applies to Windows only.</p> 1438<h4><code>NODE_PRESERVE_SYMLINKS=1</code><span><a class="mark" href="#cli_node_preserve_symlinks_1" id="cli_node_preserve_symlinks_1">#</a></span></h4> 1439<div class="api_metadata"> 1440<span>Added in: v7.1.0</span> 1441</div> 1442<p>When set to <code>1</code>, instructs the module loader to preserve symbolic links when 1443resolving and caching modules.</p> 1444<h4><code>NODE_REDIRECT_WARNINGS=file</code><span><a class="mark" href="#cli_node_redirect_warnings_file" id="cli_node_redirect_warnings_file">#</a></span></h4> 1445<div class="api_metadata"> 1446<span>Added in: v8.0.0</span> 1447</div> 1448<p>When set, process warnings will be emitted to the given file instead of 1449printing to stderr. The file will be created if it does not exist, and will be 1450appended to if it does. If an error occurs while attempting to write the 1451warning to the file, the warning will be written to stderr instead. This is 1452equivalent to using the <code>--redirect-warnings=file</code> command-line flag.</p> 1453<h4><code>NODE_REPL_HISTORY=file</code><span><a class="mark" href="#cli_node_repl_history_file" id="cli_node_repl_history_file">#</a></span></h4> 1454<div class="api_metadata"> 1455<span>Added in: v3.0.0</span> 1456</div> 1457<p>Path to the file used to store the persistent REPL history. The default path is 1458<code>~/.node_repl_history</code>, which is overridden by this variable. Setting the value 1459to an empty string (<code>''</code> or <code>' '</code>) disables persistent REPL history.</p> 1460<h4><code>NODE_REPL_EXTERNAL_MODULE=file</code><span><a class="mark" href="#cli_node_repl_external_module_file" id="cli_node_repl_external_module_file">#</a></span></h4> 1461<div class="api_metadata"> 1462<span>Added in: v13.0.0, v12.16.0</span> 1463</div> 1464<p>Path to a Node.js module which will be loaded in place of the built-in REPL. 1465Overriding this value to an empty string (<code>''</code>) will use the built-in REPL.</p> 1466<h4><code>NODE_SKIP_PLATFORM_CHECK=value</code><span><a class="mark" href="#cli_node_skip_platform_check_value" id="cli_node_skip_platform_check_value">#</a></span></h4> 1467<div class="api_metadata"> 1468<span>Added in: v14.5.0</span> 1469</div> 1470<p>If <code>value</code> equals <code>'1'</code>, the check for a supported platform is skipped during 1471Node.js startup. Node.js might not execute correctly. Any issues encountered 1472on unsupported platforms will not be fixed.</p> 1473<h4><code>NODE_TLS_REJECT_UNAUTHORIZED=value</code><span><a class="mark" href="#cli_node_tls_reject_unauthorized_value" id="cli_node_tls_reject_unauthorized_value">#</a></span></h4> 1474<p>If <code>value</code> equals <code>'0'</code>, certificate validation is disabled for TLS connections. 1475This makes TLS, and HTTPS by extension, insecure. The use of this environment 1476variable is strongly discouraged.</p> 1477<h4><code>NODE_V8_COVERAGE=dir</code><span><a class="mark" href="#cli_node_v8_coverage_dir" id="cli_node_v8_coverage_dir">#</a></span></h4> 1478<p>When set, Node.js will begin outputting <a href="https://v8project.blogspot.com/2017/12/javascript-code-coverage.html">V8 JavaScript code coverage</a> and 1479<a href="https://sourcemaps.info/spec.html">Source Map</a> data to the directory provided as an argument (coverage 1480information is written as JSON to files with a <code>coverage</code> prefix).</p> 1481<p><code>NODE_V8_COVERAGE</code> will automatically propagate to subprocesses, making it 1482easier to instrument applications that call the <code>child_process.spawn()</code> family 1483of functions. <code>NODE_V8_COVERAGE</code> can be set to an empty string, to prevent 1484propagation.</p> 1485<h5>Coverage output<span><a class="mark" href="#cli_coverage_output" id="cli_coverage_output">#</a></span></h5> 1486<p>Coverage is output as an array of <a href="https://chromedevtools.github.io/devtools-protocol/tot/Profiler#type-ScriptCoverage">ScriptCoverage</a> objects on the top-level 1487key <code>result</code>:</p> 1488<pre><code class="language-json"><span class="hljs-punctuation">{</span> 1489 <span class="hljs-attr">"result"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> 1490 <span class="hljs-punctuation">{</span> 1491 <span class="hljs-attr">"scriptId"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"67"</span><span class="hljs-punctuation">,</span> 1492 <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"internal/tty.js"</span><span class="hljs-punctuation">,</span> 1493 <span class="hljs-attr">"functions"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span><span class="hljs-punctuation">]</span> 1494 <span class="hljs-punctuation">}</span> 1495 <span class="hljs-punctuation">]</span> 1496<span class="hljs-punctuation">}</span></code></pre> 1497<h5>Source map cache<span><a class="mark" href="#cli_source_map_cache" id="cli_source_map_cache">#</a></span></h5> 1498<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p> 1499<p>If found, source map data is appended to the top-level key <code>source-map-cache</code> 1500on the JSON coverage object.</p> 1501<p><code>source-map-cache</code> is an object with keys representing the files source maps 1502were extracted from, and values which include the raw source-map URL 1503(in the key <code>url</code>), the parsed Source Map v3 information (in the key <code>data</code>), 1504and the line lengths of the source file (in the key <code>lineLengths</code>).</p> 1505<pre><code class="language-json"><span class="hljs-punctuation">{</span> 1506 <span class="hljs-attr">"result"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> 1507 <span class="hljs-punctuation">{</span> 1508 <span class="hljs-attr">"scriptId"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"68"</span><span class="hljs-punctuation">,</span> 1509 <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"file:///absolute/path/to/source.js"</span><span class="hljs-punctuation">,</span> 1510 <span class="hljs-attr">"functions"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span><span class="hljs-punctuation">]</span> 1511 <span class="hljs-punctuation">}</span> 1512 <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span> 1513 <span class="hljs-attr">"source-map-cache"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> 1514 <span class="hljs-attr">"file:///absolute/path/to/source.js"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> 1515 <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"./path-to-map.json"</span><span class="hljs-punctuation">,</span> 1516 <span class="hljs-attr">"data"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> 1517 <span class="hljs-attr">"version"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">3</span><span class="hljs-punctuation">,</span> 1518 <span class="hljs-attr">"sources"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> 1519 <span class="hljs-string">"file:///absolute/path/to/original.js"</span> 1520 <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span> 1521 <span class="hljs-attr">"names"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> 1522 <span class="hljs-string">"Foo"</span><span class="hljs-punctuation">,</span> 1523 <span class="hljs-string">"console"</span><span class="hljs-punctuation">,</span> 1524 <span class="hljs-string">"info"</span> 1525 <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span> 1526 <span class="hljs-attr">"mappings"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"MAAMA,IACJC,YAAaC"</span><span class="hljs-punctuation">,</span> 1527 <span class="hljs-attr">"sourceRoot"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"./"</span> 1528 <span class="hljs-punctuation">}</span><span class="hljs-punctuation">,</span> 1529 <span class="hljs-attr">"lineLengths"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> 1530 <span class="hljs-number">13</span><span class="hljs-punctuation">,</span> 1531 <span class="hljs-number">62</span><span class="hljs-punctuation">,</span> 1532 <span class="hljs-number">38</span><span class="hljs-punctuation">,</span> 1533 <span class="hljs-number">27</span> 1534 <span class="hljs-punctuation">]</span> 1535 <span class="hljs-punctuation">}</span> 1536 <span class="hljs-punctuation">}</span> 1537<span class="hljs-punctuation">}</span></code></pre> 1538<h4><code>NO_COLOR=<any></code><span><a class="mark" href="#cli_no_color_any" id="cli_no_color_any">#</a></span></h4> 1539<p><a href="https://no-color.org"><code>NO_COLOR</code></a> is an alias for <code>NODE_DISABLE_COLORS</code>. The value of the 1540environment variable is arbitrary.</p> 1541<h4><code>OPENSSL_CONF=file</code><span><a class="mark" href="#cli_openssl_conf_file" id="cli_openssl_conf_file">#</a></span></h4> 1542<div class="api_metadata"> 1543<span>Added in: v6.11.0</span> 1544</div> 1545<p>Load an OpenSSL configuration file on startup. Among other uses, this can be 1546used to enable FIPS-compliant crypto if Node.js is built with <code>./configure --openssl-fips</code>.</p> 1547<p>If the <a href="#cli_openssl_config_file"><code>--openssl-config</code></a> command-line option is used, the environment 1548variable is ignored.</p> 1549<h4><code>SSL_CERT_DIR=dir</code><span><a class="mark" href="#cli_ssl_cert_dir_dir" id="cli_ssl_cert_dir_dir">#</a></span></h4> 1550<div class="api_metadata"> 1551<span>Added in: v7.7.0</span> 1552</div> 1553<p>If <code>--use-openssl-ca</code> is enabled, this overrides and sets OpenSSL's directory 1554containing trusted certificates.</p> 1555<p>Be aware that unless the child environment is explicitly set, this environment 1556variable will be inherited by any child processes, and if they use OpenSSL, it 1557may cause them to trust the same CAs as node.</p> 1558<h4><code>SSL_CERT_FILE=file</code><span><a class="mark" href="#cli_ssl_cert_file_file" id="cli_ssl_cert_file_file">#</a></span></h4> 1559<div class="api_metadata"> 1560<span>Added in: v7.7.0</span> 1561</div> 1562<p>If <code>--use-openssl-ca</code> is enabled, this overrides and sets OpenSSL's file 1563containing trusted certificates.</p> 1564<p>Be aware that unless the child environment is explicitly set, this environment 1565variable will be inherited by any child processes, and if they use OpenSSL, it 1566may cause them to trust the same CAs as node.</p> 1567<h4><code>UV_THREADPOOL_SIZE=size</code><span><a class="mark" href="#cli_uv_threadpool_size_size" id="cli_uv_threadpool_size_size">#</a></span></h4> 1568<p>Set the number of threads used in libuv's threadpool to <code>size</code> threads.</p> 1569<p>Asynchronous system APIs are used by Node.js whenever possible, but where they 1570do not exist, libuv's threadpool is used to create asynchronous node APIs based 1571on synchronous system APIs. Node.js APIs that use the threadpool are:</p> 1572<ul> 1573<li>all <code>fs</code> APIs, other than the file watcher APIs and those that are explicitly 1574synchronous</li> 1575<li>asynchronous crypto APIs such as <code>crypto.pbkdf2()</code>, <code>crypto.scrypt()</code>, 1576<code>crypto.randomBytes()</code>, <code>crypto.randomFill()</code>, <code>crypto.generateKeyPair()</code></li> 1577<li><code>dns.lookup()</code></li> 1578<li>all <code>zlib</code> APIs, other than those that are explicitly synchronous</li> 1579</ul> 1580<p>Because libuv's threadpool has a fixed size, it means that if for whatever 1581reason any of these APIs takes a long time, other (seemingly unrelated) APIs 1582that run in libuv's threadpool will experience degraded performance. In order to 1583mitigate this issue, one potential solution is to increase the size of libuv's 1584threadpool by setting the <code>'UV_THREADPOOL_SIZE'</code> environment variable to a value 1585greater than <code>4</code> (its current default value). For more information, see the 1586<a href="https://docs.libuv.org/en/latest/threadpool.html">libuv threadpool documentation</a>.</p> 1587</section><section><h3>Useful V8 options<span><a class="mark" href="#cli_useful_v8_options" id="cli_useful_v8_options">#</a></span></h3> 1588<p>V8 has its own set of CLI options. Any V8 CLI option that is provided to <code>node</code> 1589will be passed on to V8 to handle. V8's options have <em>no stability guarantee</em>. 1590The V8 team themselves don't consider them to be part of their formal API, 1591and reserve the right to change them at any time. Likewise, they are not 1592covered by the Node.js stability guarantees. Many of the V8 1593options are of interest only to V8 developers. Despite this, there is a small 1594set of V8 options that are widely applicable to Node.js, and they are 1595documented here:</p> 1596<h4><code>--max-old-space-size=SIZE</code> (in megabytes)<span><a class="mark" href="#cli_max_old_space_size_size_in_megabytes" id="cli_max_old_space_size_size_in_megabytes">#</a></span></h4> 1597<p>Sets the max memory size of V8's old memory section. As memory 1598consumption approaches the limit, V8 will spend more time on 1599garbage collection in an effort to free unused memory.</p> 1600<p>On a machine with 2GB of memory, consider setting this to 16011536 (1.5GB) to leave some memory for other uses and avoid swapping.</p> 1602<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --max-old-space-size=1536 index.js</span></code></pre></section> 1603 <!-- API END --> 1604 </div> 1605 </div> 1606 </div> 1607 <script> 1608 'use strict'; 1609 { 1610 const kCustomPreference = 'customDarkTheme'; 1611 const userSettings = sessionStorage.getItem(kCustomPreference); 1612 const themeToggleButton = document.getElementById('theme-toggle-btn'); 1613 if (userSettings === null && window.matchMedia) { 1614 const mq = window.matchMedia('(prefers-color-scheme: dark)'); 1615 if ('onchange' in mq) { 1616 function mqChangeListener(e) { 1617 document.body.classList.toggle('dark-mode', e.matches); 1618 } 1619 mq.addEventListener('change', mqChangeListener); 1620 if (themeToggleButton) { 1621 themeToggleButton.addEventListener('click', function() { 1622 mq.removeEventListener('change', mqChangeListener); 1623 }, { once: true }); 1624 } 1625 } 1626 if (mq.matches) { 1627 document.body.classList.add('dark-mode'); 1628 } 1629 } else if (userSettings === 'true') { 1630 document.body.classList.add('dark-mode'); 1631 } 1632 if (themeToggleButton) { 1633 themeToggleButton.hidden = false; 1634 themeToggleButton.addEventListener('click', function() { 1635 sessionStorage.setItem( 1636 kCustomPreference, 1637 document.body.classList.toggle('dark-mode') 1638 ); 1639 }); 1640 } 1641 } 1642 </script> 1643</body> 1644</html> 1645