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diff --git a/lib/internal/readline/utils.js b/lib/internal/readline/utils.js
new file mode 100644
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@@ -0,0 +1,430 @@
+'use strict';
+
+// Regex used for ansi escape code splitting
+// Adopted from https://github.com/chalk/ansi-regex/blob/master/index.js
+// License: MIT, authors: @sindresorhus, Qix-, and arjunmehta
+// Matches all ansi escape code sequences in a string
+/* eslint-disable no-control-regex */
+const ansi =
+  /[\u001b\u009b][[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-ORZcf-nqry=><]/g;
+/* eslint-enable no-control-regex */
+const kUTF16SurrogateThreshold = 0x10000; // 2 ** 16
+const kEscape = '\x1b';
+
+let getStringWidth;
+let isFullWidthCodePoint;
+
+function CSI(strings, ...args) {
+  let ret = `${kEscape}[`;
+  for (var n = 0; n < strings.length; n++) {
+    ret += strings[n];
+    if (n < args.length)
+      ret += args[n];
+  }
+  return ret;
+}
+
+CSI.kEscape = kEscape;
+CSI.kClearToBeginning = CSI`1K`;
+CSI.kClearToEnd = CSI`0K`;
+CSI.kClearLine = CSI`2K`;
+CSI.kClearScreenDown = CSI`0J`;
+
+if (internalBinding('config').hasIntl) {
+  const icu = internalBinding('icu');
+  getStringWidth = function getStringWidth(str, options) {
+    options = options || {};
+    if (!Number.isInteger(str))
+      str = stripVTControlCharacters(String(str));
+    return icu.getStringWidth(
+      str,
+      Boolean(options.ambiguousAsFullWidth),
+      Boolean(options.expandEmojiSequence)
+    );
+  };
+  isFullWidthCodePoint =
+    function isFullWidthCodePoint(code, options) {
+      if (typeof code !== 'number')
+        return false;
+      return icu.getStringWidth(code, options) === 2;
+    };
+} else {
+  /**
+   * Returns the number of columns required to display the given string.
+   */
+  getStringWidth = function getStringWidth(str) {
+    if (Number.isInteger(str))
+      return isFullWidthCodePoint(str) ? 2 : 1;
+
+    let width = 0;
+
+    str = stripVTControlCharacters(String(str));
+
+    for (var i = 0; i < str.length; i++) {
+      const code = str.codePointAt(i);
+
+      if (code >= kUTF16SurrogateThreshold) { // Surrogates.
+        i++;
+      }
+
+      if (isFullWidthCodePoint(code)) {
+        width += 2;
+      } else {
+        width++;
+      }
+    }
+
+    return width;
+  };
+
+  /**
+   * Returns true if the character represented by a given
+   * Unicode code point is full-width. Otherwise returns false.
+   */
+  isFullWidthCodePoint = function isFullWidthCodePoint(code) {
+    // Code points are derived from:
+    // http://www.unicode.org/Public/UNIDATA/EastAsianWidth.txt
+    return Number.isInteger(code) && code >= 0x1100 && (
+      code <= 0x115f ||  // Hangul Jamo
+      code === 0x2329 || // LEFT-POINTING ANGLE BRACKET
+      code === 0x232a || // RIGHT-POINTING ANGLE BRACKET
+      // CJK Radicals Supplement .. Enclosed CJK Letters and Months
+      code >= 0x2e80 && code <= 0x3247 && code !== 0x303f ||
+      // Enclosed CJK Letters and Months .. CJK Unified Ideographs Extension A
+      code >= 0x3250 && code <= 0x4dbf ||
+      // CJK Unified Ideographs .. Yi Radicals
+      code >= 0x4e00 && code <= 0xa4c6 ||
+      // Hangul Jamo Extended-A
+      code >= 0xa960 && code <= 0xa97c ||
+      // Hangul Syllables
+      code >= 0xac00 && code <= 0xd7a3 ||
+      // CJK Compatibility Ideographs
+      code >= 0xf900 && code <= 0xfaff ||
+      // Vertical Forms
+      code >= 0xfe10 && code <= 0xfe19 ||
+      // CJK Compatibility Forms .. Small Form Variants
+      code >= 0xfe30 && code <= 0xfe6b ||
+      // Halfwidth and Fullwidth Forms
+      code >= 0xff01 && code <= 0xff60 ||
+      code >= 0xffe0 && code <= 0xffe6 ||
+      // Kana Supplement
+      code >= 0x1b000 && code <= 0x1b001 ||
+      // Enclosed Ideographic Supplement
+      code >= 0x1f200 && code <= 0x1f251 ||
+      // CJK Unified Ideographs Extension B .. Tertiary Ideographic Plane
+      code >= 0x20000 && code <= 0x3fffd
+    );
+  };
+}
+
+/**
+ * Tries to remove all VT control characters. Use to estimate displayed
+ * string width. May be buggy due to not running a real state machine
+ */
+function stripVTControlCharacters(str) {
+  return str.replace(ansi, '');
+}
+
+
+/*
+  Some patterns seen in terminal key escape codes, derived from combos seen
+  at http://www.midnight-commander.org/browser/lib/tty/key.c
+
+  ESC letter
+  ESC [ letter
+  ESC [ modifier letter
+  ESC [ 1 ; modifier letter
+  ESC [ num char
+  ESC [ num ; modifier char
+  ESC O letter
+  ESC O modifier letter
+  ESC O 1 ; modifier letter
+  ESC N letter
+  ESC [ [ num ; modifier char
+  ESC [ [ 1 ; modifier letter
+  ESC ESC [ num char
+  ESC ESC O letter
+
+  - char is usually ~ but $ and ^ also happen with rxvt
+  - modifier is 1 +
+                (shift     * 1) +
+                (left_alt  * 2) +
+                (ctrl      * 4) +
+                (right_alt * 8)
+  - two leading ESCs apparently mean the same as one leading ESC
+*/
+function* emitKeys(stream) {
+  while (true) {
+    let ch = yield;
+    let s = ch;
+    let escaped = false;
+    const key = {
+      sequence: null,
+      name: undefined,
+      ctrl: false,
+      meta: false,
+      shift: false
+    };
+
+    if (ch === kEscape) {
+      escaped = true;
+      s += (ch = yield);
+
+      if (ch === kEscape) {
+        s += (ch = yield);
+      }
+    }
+
+    if (escaped && (ch === 'O' || ch === '[')) {
+      // ANSI escape sequence
+      let code = ch;
+      let modifier = 0;
+
+      if (ch === 'O') {
+        // ESC O letter
+        // ESC O modifier letter
+        s += (ch = yield);
+
+        if (ch >= '0' && ch <= '9') {
+          modifier = (ch >> 0) - 1;
+          s += (ch = yield);
+        }
+
+        code += ch;
+      } else if (ch === '[') {
+        // ESC [ letter
+        // ESC [ modifier letter
+        // ESC [ [ modifier letter
+        // ESC [ [ num char
+        s += (ch = yield);
+
+        if (ch === '[') {
+          // \x1b[[A
+          //      ^--- escape codes might have a second bracket
+          code += ch;
+          s += (ch = yield);
+        }
+
+        /*
+         * Here and later we try to buffer just enough data to get
+         * a complete ascii sequence.
+         *
+         * We have basically two classes of ascii characters to process:
+         *
+         *
+         * 1. `\x1b[24;5~` should be parsed as { code: '[24~', modifier: 5 }
+         *
+         * This particular example is featuring Ctrl+F12 in xterm.
+         *
+         *  - `;5` part is optional, e.g. it could be `\x1b[24~`
+         *  - first part can contain one or two digits
+         *
+         * So the generic regexp is like /^\d\d?(;\d)?[~^$]$/
+         *
+         *
+         * 2. `\x1b[1;5H` should be parsed as { code: '[H', modifier: 5 }
+         *
+         * This particular example is featuring Ctrl+Home in xterm.
+         *
+         *  - `1;5` part is optional, e.g. it could be `\x1b[H`
+         *  - `1;` part is optional, e.g. it could be `\x1b[5H`
+         *
+         * So the generic regexp is like /^((\d;)?\d)?[A-Za-z]$/
+         *
+         */
+        const cmdStart = s.length - 1;
+
+        // Skip one or two leading digits
+        if (ch >= '0' && ch <= '9') {
+          s += (ch = yield);
+
+          if (ch >= '0' && ch <= '9') {
+            s += (ch = yield);
+          }
+        }
+
+        // skip modifier
+        if (ch === ';') {
+          s += (ch = yield);
+
+          if (ch >= '0' && ch <= '9') {
+            s += yield;
+          }
+        }
+
+        /*
+         * We buffered enough data, now trying to extract code
+         * and modifier from it
+         */
+        const cmd = s.slice(cmdStart);
+        let match;
+
+        if ((match = cmd.match(/^(\d\d?)(;(\d))?([~^$])$/))) {
+          code += match[1] + match[4];
+          modifier = (match[3] || 1) - 1;
+        } else if ((match = cmd.match(/^((\d;)?(\d))?([A-Za-z])$/))) {
+          code += match[4];
+          modifier = (match[3] || 1) - 1;
+        } else {
+          code += cmd;
+        }
+      }
+
+      // Parse the key modifier
+      key.ctrl = !!(modifier & 4);
+      key.meta = !!(modifier & 10);
+      key.shift = !!(modifier & 1);
+      key.code = code;
+
+      // Parse the key itself
+      switch (code) {
+        /* xterm/gnome ESC O letter */
+        case 'OP': key.name = 'f1'; break;
+        case 'OQ': key.name = 'f2'; break;
+        case 'OR': key.name = 'f3'; break;
+        case 'OS': key.name = 'f4'; break;
+
+        /* xterm/rxvt ESC [ number ~ */
+        case '[11~': key.name = 'f1'; break;
+        case '[12~': key.name = 'f2'; break;
+        case '[13~': key.name = 'f3'; break;
+        case '[14~': key.name = 'f4'; break;
+
+        /* from Cygwin and used in libuv */
+        case '[[A': key.name = 'f1'; break;
+        case '[[B': key.name = 'f2'; break;
+        case '[[C': key.name = 'f3'; break;
+        case '[[D': key.name = 'f4'; break;
+        case '[[E': key.name = 'f5'; break;
+
+        /* common */
+        case '[15~': key.name = 'f5'; break;
+        case '[17~': key.name = 'f6'; break;
+        case '[18~': key.name = 'f7'; break;
+        case '[19~': key.name = 'f8'; break;
+        case '[20~': key.name = 'f9'; break;
+        case '[21~': key.name = 'f10'; break;
+        case '[23~': key.name = 'f11'; break;
+        case '[24~': key.name = 'f12'; break;
+
+        /* xterm ESC [ letter */
+        case '[A': key.name = 'up'; break;
+        case '[B': key.name = 'down'; break;
+        case '[C': key.name = 'right'; break;
+        case '[D': key.name = 'left'; break;
+        case '[E': key.name = 'clear'; break;
+        case '[F': key.name = 'end'; break;
+        case '[H': key.name = 'home'; break;
+
+        /* xterm/gnome ESC O letter */
+        case 'OA': key.name = 'up'; break;
+        case 'OB': key.name = 'down'; break;
+        case 'OC': key.name = 'right'; break;
+        case 'OD': key.name = 'left'; break;
+        case 'OE': key.name = 'clear'; break;
+        case 'OF': key.name = 'end'; break;
+        case 'OH': key.name = 'home'; break;
+
+        /* xterm/rxvt ESC [ number ~ */
+        case '[1~': key.name = 'home'; break;
+        case '[2~': key.name = 'insert'; break;
+        case '[3~': key.name = 'delete'; break;
+        case '[4~': key.name = 'end'; break;
+        case '[5~': key.name = 'pageup'; break;
+        case '[6~': key.name = 'pagedown'; break;
+
+        /* putty */
+        case '[[5~': key.name = 'pageup'; break;
+        case '[[6~': key.name = 'pagedown'; break;
+
+        /* rxvt */
+        case '[7~': key.name = 'home'; break;
+        case '[8~': key.name = 'end'; break;
+
+        /* rxvt keys with modifiers */
+        case '[a': key.name = 'up'; key.shift = true; break;
+        case '[b': key.name = 'down'; key.shift = true; break;
+        case '[c': key.name = 'right'; key.shift = true; break;
+        case '[d': key.name = 'left'; key.shift = true; break;
+        case '[e': key.name = 'clear'; key.shift = true; break;
+
+        case '[2$': key.name = 'insert'; key.shift = true; break;
+        case '[3$': key.name = 'delete'; key.shift = true; break;
+        case '[5$': key.name = 'pageup'; key.shift = true; break;
+        case '[6$': key.name = 'pagedown'; key.shift = true; break;
+        case '[7$': key.name = 'home'; key.shift = true; break;
+        case '[8$': key.name = 'end'; key.shift = true; break;
+
+        case 'Oa': key.name = 'up'; key.ctrl = true; break;
+        case 'Ob': key.name = 'down'; key.ctrl = true; break;
+        case 'Oc': key.name = 'right'; key.ctrl = true; break;
+        case 'Od': key.name = 'left'; key.ctrl = true; break;
+        case 'Oe': key.name = 'clear'; key.ctrl = true; break;
+
+        case '[2^': key.name = 'insert'; key.ctrl = true; break;
+        case '[3^': key.name = 'delete'; key.ctrl = true; break;
+        case '[5^': key.name = 'pageup'; key.ctrl = true; break;
+        case '[6^': key.name = 'pagedown'; key.ctrl = true; break;
+        case '[7^': key.name = 'home'; key.ctrl = true; break;
+        case '[8^': key.name = 'end'; key.ctrl = true; break;
+
+        /* misc. */
+        case '[Z': key.name = 'tab'; key.shift = true; break;
+        default: key.name = 'undefined'; break;
+      }
+    } else if (ch === '\r') {
+      // carriage return
+      key.name = 'return';
+    } else if (ch === '\n') {
+      // Enter, should have been called linefeed
+      key.name = 'enter';
+    } else if (ch === '\t') {
+      // tab
+      key.name = 'tab';
+    } else if (ch === '\b' || ch === '\x7f') {
+      // backspace or ctrl+h
+      key.name = 'backspace';
+      key.meta = escaped;
+    } else if (ch === kEscape) {
+      // escape key
+      key.name = 'escape';
+      key.meta = escaped;
+    } else if (ch === ' ') {
+      key.name = 'space';
+      key.meta = escaped;
+    } else if (!escaped && ch <= '\x1a') {
+      // ctrl+letter
+      key.name = String.fromCharCode(ch.charCodeAt(0) + 'a'.charCodeAt(0) - 1);
+      key.ctrl = true;
+    } else if (/^[0-9A-Za-z]$/.test(ch)) {
+      // Letter, number, shift+letter
+      key.name = ch.toLowerCase();
+      key.shift = /^[A-Z]$/.test(ch);
+      key.meta = escaped;
+    } else if (escaped) {
+      // Escape sequence timeout
+      key.name = ch.length ? undefined : 'escape';
+      key.meta = true;
+    }
+
+    key.sequence = s;
+
+    if (s.length !== 0 && (key.name !== undefined || escaped)) {
+      /* Named character or sequence */
+      stream.emit('keypress', escaped ? undefined : s, key);
+    } else if (s.length === 1) {
+      /* Single unnamed character, e.g. "." */
+      stream.emit('keypress', s, key);
+    }
+    /* Unrecognized or broken escape sequence, don't emit anything */
+  }
+}
+
+module.exports = {
+  emitKeys,
+  getStringWidth,
+  isFullWidthCodePoint,
+  kUTF16SurrogateThreshold,
+  stripVTControlCharacters,
+  CSI
+};