neo-blessed/lib/tput.js

/**
 * tput.js - parse and compile terminfo caps to javascript.
 * Copyright (c) 2013-2015, Christopher Jeffrey and contributors (MIT License).
 * https://github.com/chjj/blessed
 */

// Resources:
//   $ man term
//   $ man terminfo
//   http://invisible-island.net/ncurses/man/term.5.html
//   https://en.wikipedia.org/wiki/Terminfo

// Todo:
// - xterm's XT (set-title capability?) value should
//   be true (at least tmux thinks it should).
//   It's not parsed as true. Investigate.
// - Possibly switch to other method of finding the
//   extended data string table: i += h.symOffsetCount * 2;

/**
 * Modules
 */

var assert = require('assert')
  , path = require('path')
  , fs = require('fs');

/**
 * Tput
 */

function Tput(options) {
  if (!(this instanceof Tput)) {
    return new Tput(options);
  }

  options = options || {};
  if (typeof options === 'string') {
    options = { term: options };
  }

  this.options = options;
  this.terminal = options.term
    || options.terminal
    || process.env.TERM
    || (process.platform === 'win32' ? 'windows-ansi' : 'xterm');

  this.debug = options.debug;
  this.padding = options.padding;
  this.extended = options.extended;
  this.printf = options.printf;
  this.termcap = options.termcap;

  this.terminfoPrefix = options.terminfoPrefix;
  this.terminfoFile = options.terminfoFile;
  this.termcapFile = options.termcapFile;

  if (options.term || options.terminal) {
    this.setup();
  }
};

Tput.prototype.setup = function() {
  try {
    if (this.termcap) {
      try {
        this.injectTermcap();
      } catch (e) {
        if (this.debug) throw e;
        this._useInternalCap(this.terminal);
      }
    } else {
      try {
        this.injectTerminfo();
      } catch (e) {
        if (this.debug) throw e;
        this._useInternalInfo(this.terminal);
      }
    }
  } catch (e) {
    // If there was an error, fallback
    // to an internally stored terminfo/cap.
    if (this.debug) throw e;
    this._useXtermInfo();
  }
};

Tput.prototype.term = function(is) {
  return this.terminal.indexOf(is) === 0;
};

Tput.prototype._debug = function() {
  if (!this.debug) return;
  return console.log.apply(console, arguments);
};

/**
 * Fallback
 */

Tput.prototype._useVt102Cap = function() {
  return this.injectTermcap('vt102');
};

Tput.prototype._useXtermCap = function() {
  return this.injectTermcap(__dirname + '/../usr/xterm.termcap');
};

Tput.prototype._useXtermInfo = function() {
  return this.injectTerminfo(__dirname + '/../usr/xterm');
};

Tput.prototype._useInternalInfo = function(name) {
  name = path.basename(name);
  return this.injectTerminfo(__dirname + '/../usr/' + name);
};

Tput.prototype._useInternalCap = function(name) {
  name = path.basename(name);
  return this.injectTermcap(__dirname + '/../usr/' + name + '.termcap');
};

/**
 * Terminfo
 */

Tput.ipaths = [
  process.env.TERMINFO || '',
  (process.env.TERMINFO_DIRS || '').split(':'),
  (process.env.HOME || '') + '/.terminfo',
  '/usr/share/terminfo',
  '/usr/share/lib/terminfo',
  '/usr/lib/terminfo',
  '/usr/local/share/terminfo',
  '/usr/local/share/lib/terminfo',
  '/usr/local/lib/terminfo',
  '/usr/local/ncurses/lib/terminfo'
];

Tput.prototype.readTerminfo = function(term) {
  var term = term || this.terminal
    , data
    , file
    , info;

  file = path.normalize(this._prefix(term));
  data = fs.readFileSync(file);
  info = this.parseTerminfo(data, file);

  if (this.debug) {
    this._terminfo = info;
  }

  return info;
};

Tput._prefix =
Tput.prototype._prefix = function(term) {
  // If we have a terminfoFile, or our
  // term looks like a filename, use it.
  if (term) {
    if (~term.indexOf(path.sep)) {
      return term;
    }
    if (this.terminfoFile) {
      return this.terminfoFile;
    }
  }

  var paths = Tput.ipaths.slice()
    , file;

  if (this.terminfoPrefix) {
    paths.unshift(this.terminfoPrefix);
  }

  // Try exact matches.
  file = this._tprefix(paths, term);
  if (file) return file;

  // Try similar matches.
  file = this._tprefix(paths, term, true);
  if (file) return file;

  // Not found.
  throw new Error('Terminfo directory not found.');
};

Tput._tprefix =
Tput.prototype._tprefix = function(prefix, term, soft) {
  if (!prefix) return;

  var file
    , dir
    , ch
    , i
    , sdiff
    , sfile
    , list;

  if (Array.isArray(prefix)) {
    for (i = 0; i < prefix.length; i++) {
      file = this._tprefix(prefix[i], term, soft);
      if (file) return file;
    }
    return;
  }

  var find = function(word) {
    var file, ch;

    file = path.resolve(prefix, word[0]);
    try {
      fs.statSync(file);
      return file;
    } catch (e) {
      ;
    }

    ch = word[0].charCodeAt(0).toString(16);
    if (ch.length < 2) ch = '0' + ch;

    file = path.resolve(prefix, ch);
    try {
      fs.statSync(file);
      return file;
    } catch (e) {
      ;
    }
  };

  if (!term) {
    // Make sure the directory's sub-directories
    // are all one-letter, or hex digits.
    // return find('x') ? prefix : null;
    try {
      dir = fs.readdirSync(prefix).filter(function(file) {
        return file.length !== 1 && !/^[0-9a-fA-F]{2}$/.test(file);
      });
      if (!dir.length) {
        return prefix;
      }
    } catch (e) {
      ;
    }
    return;
  }

  term = path.basename(term);
  dir = find(term);

  if (!dir) return;

  if (soft) {
    try {
      list = fs.readdirSync(dir);
    } catch (e) {
      return;
    }

    list.forEach(function(file) {
      if (file.indexOf(term) === 0) {
        var diff = file.length - term.length;
        if (!sfile || diff < sdiff) {
          sdiff = diff;
          sfile = file;
        }
      }
    });

    return sfile && (soft || sdiff === 0)
      ? path.resolve(dir, sfile)
      : null;
  }

  file = path.resolve(dir, term);
  try {
    fs.statSync(file);
    return file;
  } catch (e) {
    ;
  }
};

/**
 * Terminfo Parser
 * All shorts are little-endian
 */

Tput.prototype.parseTerminfo = function(data, file) {
  var info = {}
    , extended
    , l = data.length
    , i = 0
    , v
    , o;

  var h = info.header = {
    dataSize: data.length,
    headerSize: 12,
    magicNumber: (data[1] << 8) | data[0],
    namesSize: (data[3] << 8) | data[2],
    boolCount: (data[5] << 8) | data[4],
    numCount: (data[7] << 8) | data[6],
    strCount: (data[9] << 8) | data[8],
    strTableSize: (data[11] << 8) | data[10]
  };

  h.total = h.headerSize
    + h.namesSize
    + h.boolCount
    + h.numCount * 2
    + h.strCount * 2
    + h.strTableSize;

  i += h.headerSize;

  // Names Section
  var names = data.toString('ascii', i, i + h.namesSize - 1)
    , parts = names.split('|')
    , name = parts[0]
    , desc = parts.pop();

  info.name = name;
  info.names = parts;
  info.desc = desc;

  info.dir = path.resolve(file, '..', '..');
  info.file = file;

  i += h.namesSize - 1;

  // Names is nul-terminated.
  assert.equal(data[i], 0);
  i++;

  // Booleans Section
  // One byte for each flag
  // Same order as <term.h>
  info.bools = {};
  l = i + h.boolCount;
  o = 0;
  for (; i < l; i++) {
    v = Tput.bools[o++];
    info.bools[v] = data[i] === 1;
  }

  // Null byte in between to make sure numbers begin on an even byte.
  if (i % 2) {
    assert.equal(data[i], 0);
    i++;
  }

  // Numbers Section
  info.numbers = {};
  l = i + h.numCount * 2;
  o = 0;
  for (; i < l; i += 2) {
    v = Tput.numbers[o++];
    if (data[i + 1] === 0377 && data[i] === 0377) {
      info.numbers[v] = -1;
    } else {
      info.numbers[v] = (data[i + 1] << 8) | data[i];
    }
  }

  // Strings Section
  info.strings = {};
  l = i + h.strCount * 2;
  o = 0;
  for (; i < l; i += 2) {
    v = Tput.strings[o++];
    if (data[i + 1] === 0377 && data[i] === 0377) {
      info.strings[v] = -1;
    } else {
      info.strings[v] = (data[i + 1] << 8) | data[i];
    }
  }

  // String Table
  Object.keys(info.strings).forEach(function(key) {
    if (info.strings[key] === -1) {
      delete info.strings[key];
      return;
    }

    // Workaround: fix an odd bug in the screen-256color terminfo where it tries
    // to set -1, but it appears to have {0xfe, 0xff} instead of {0xff, 0xff}.
    // TODO: Possibly handle errors gracefully below, as well as in the
    // extended info. Also possibly do: `if (info.strings[key] >= data.length)`.
    if (info.strings[key] === 65534) {
      delete info.strings[key];
      return;
    }

    var s = i + info.strings[key]
      , j = s;

    while (data[j]) j++;

    assert(j < data.length);

    info.strings[key] = data.toString('ascii', s, j);
  });

  // Extended Header
  if (this.extended !== false) {
    i--;
    i += h.strTableSize;
    if (i % 2) {
      assert.equal(data[i], 0);
      i++;
    }
    l = data.length;
    if (i < l - 1) {
      try {
        extended = this.parseExtended(data.slice(i));
      } catch (e) {
        if (this.debug) {
          throw e;
        }
        return info;
      }
      info.header.extended = extended.header;
      ['bools', 'numbers', 'strings'].forEach(function(key) {
        merge(info[key], extended[key]);
      });
    }
  }

  return info;
};

/**
 * Extended Parsing
 */

// Some data to help understand:

// For xterm, non-extended header:
// { dataSize: 3270,
//   headerSize: 12,
//   magicNumber: 282,
//   namesSize: 48,
//   boolCount: 38,
//   numCount: 15,
//   strCount: 413,
//   strTableSize: 1388,
//   total: 2342 }

// For xterm, header:
// Offset: 2342
// { header:
//    { dataSize: 928,
//      headerSize: 10,
//      boolCount: 2,
//      numCount: 1,
//      strCount: 57,
//      strTableSize: 117,
//      lastStrTableOffset: 680,
//      total: 245 },

// For xterm, layout:
// { header: '0 - 10', // length: 10
//   bools: '10 - 12', // length: 2
//   numbers: '12 - 14', // length: 2
//   strings: '14 - 128', // length: 114 (57 short)
//   symoffsets: '128 - 248', // length: 120 (60 short)
//   stringtable: '248 - 612', // length: 364
//   sym: '612 - 928' } // length: 316
//
// How lastStrTableOffset works:
//   data.length - h.lastStrTableOffset === 248
//     (sym-offset end, string-table start)
//   364 + 316 === 680 (lastStrTableOffset)
// How strTableSize works:
//   h.strCount + [symOffsetCount] === h.strTableSize
//   57 + 60 === 117 (strTableSize)
//   symOffsetCount doesn't actually exist in the header. it's just implied.
// Getting the number of sym offsets:
//   h.symOffsetCount = h.strTableSize - h.strCount;
//   h.symOffsetSize = (h.strTableSize - h.strCount) * 2;

Tput.prototype.parseExtended = function(data) {
  var info = {}
    , l = data.length
    , i = 0;

  var h = info.header = {
    dataSize: data.length,
    headerSize: 10,
    boolCount: (data[i + 1] << 8) | data[i + 0],
    numCount: (data[i + 3] << 8) | data[i + 2],
    strCount: (data[i + 5] << 8) | data[i + 4],
    strTableSize: (data[i + 7] << 8) | data[i + 6],
    lastStrTableOffset: (data[i + 9] << 8) | data[i + 8]
  };

  // h.symOffsetCount = h.strTableSize - h.strCount;

  h.total = h.headerSize
    + h.boolCount
    + h.numCount * 2
    + h.strCount * 2
    + h.strTableSize;

  i += h.headerSize;

  // Booleans Section
  // One byte for each flag
  var _bools = [];
  l = i + h.boolCount;
  for (; i < l; i++) {
    _bools.push(data[i] === 1);
  }

  // Null byte in between to make sure numbers begin on an even byte.
  if (i % 2) {
    assert.equal(data[i], 0);
    i++;
  }

  // Numbers Section
  var _numbers = [];
  l = i + h.numCount * 2;
  for (; i < l; i += 2) {
    if (data[i + 1] === 0377 && data[i] === 0377) {
      _numbers.push(-1);
    } else {
      _numbers.push((data[i + 1] << 8) | data[i]);
    }
  }

  // Strings Section
  var _strings = [];
  l = i + h.strCount * 2;
  for (; i < l; i += 2) {
    if (data[i + 1] === 0377 && data[i] === 0377) {
      _strings.push(-1);
    } else {
      _strings.push((data[i + 1] << 8) | data[i]);
    }
  }

  // Pass over the sym offsets and get to the string table.
  i = data.length - h.lastStrTableOffset;
  // Might be better to do this instead if the file has trailing bytes:
  // i += h.symOffsetCount * 2;

  // String Table
  var high = 0;
  _strings.forEach(function(offset, k) {
    if (offset === -1) {
      _strings[k] = '';
      return;
    }

    var s = i + offset
      , j = s;

    while (data[j]) j++;

    assert(j < data.length);

    // Find out where the string table ends by
    // getting the highest string length.
    if (high < j - i) {
      high = j - i;
    }

    _strings[k] = data.toString('ascii', s, j);
  });

  // Symbol Table
  // Add one to the highest string length because we didn't count \0.
  i += high + 1;
  l = data.length;

  var sym = []
    , j;

  for (; i < l; i++) {
    j = i;
    while (data[j]) j++;
    sym.push(data.toString('ascii', i, j));
    i = j;
  }

  // Identify by name
  j = 0;

  info.bools = {};
  _bools.forEach(function(bool) {
    info.bools[sym[j++]] = bool;
  });

  info.numbers = {};
  _numbers.forEach(function(number) {
    info.numbers[sym[j++]] = number;
  });

  info.strings = {};
  _strings.forEach(function(string) {
    info.strings[sym[j++]] = string;
  });

  // Should be the very last bit of data.
  assert.equal(i, data.length);

  return info;
};

Tput.prototype.compileTerminfo = function(term) {
  return this.compile(this.readTerminfo(term));
};

Tput.prototype.injectTerminfo = function(term) {
  return this.inject(this.compileTerminfo(term));
};

/**
 * Compiler - terminfo cap->javascript
 */

Tput.prototype.compile = function(info) {
  var self = this;

  if (!info) {
    throw new Error('Terminal not found.');
  }

  this.detectFeatures(info);

  this._debug(info);

  info.all = {};
  info.methods = {};

  ['bools', 'numbers', 'strings'].forEach(function(type) {
    Object.keys(info[type]).forEach(function(key) {
      info.all[key] = info[type][key];
      info.methods[key] = self._compile(info, key, info.all[key]);
    });
  });

  Tput.bools.forEach(function(key) {
    if (info.methods[key] == null) info.methods[key] = false;
  });

  Tput.numbers.forEach(function(key) {
    if (info.methods[key] == null) info.methods[key] = -1;
  });

  Tput.strings.forEach(function(key) {
    if (!info.methods[key]) info.methods[key] = noop;
  });

  Object.keys(info.methods).forEach(function(key) {
    if (!Tput.alias[key]) return;
    Tput.alias[key].forEach(function(alias) {
      info.methods[alias] = info.methods[key];
    });
    // Could just use:
    // Object.keys(Tput.aliasMap).forEach(function(key) {
    //   info.methods[key] = info.methods[Tput.aliasMap[key]];
    // });
  });

  return info;
};

Tput.prototype.inject = function(info) {
  var self = this
    , methods = info.methods || info;

  Object.keys(methods).forEach(function(key) {
    if (typeof methods[key] !== 'function') {
      self[key] = methods[key];
      return;
    }
    self[key] = function() {
      var args = Array.prototype.slice.call(arguments);
      return methods[key].call(self, args);
    };
  });

  this.info = info;
  this.all = info.all;
  this.methods = info.methods;
  this.bools = info.bools;
  this.numbers = info.numbers;
  this.strings = info.strings;

  if (!~info.names.indexOf(this.terminal)) {
    this.terminal = info.name;
  }

  this.features = info.features;
  Object.keys(info.features).forEach(function(key) {
    self[key] = info.features[key];
  });
};

// See:
// ~/ncurses/ncurses/tinfo/lib_tparm.c
// ~/ncurses/ncurses/tinfo/comp_scan.c
Tput.prototype._compile = function(info, key, str) {
  var self = this;

  this._debug('Compiling %s: %s', key, JSON.stringify(str));

  switch (typeof str) {
    case 'boolean':
      return str;
    case 'number':
      return str;
    case 'string':
      break;
    default:
      return noop;
  }

  if (!str) {
    return noop;
  }

  // See:
  // ~/ncurses/progs/tput.c - tput() - L149
  // ~/ncurses/progs/tset.c - set_init() - L992
  if (key === 'init_file' || key === 'reset_file') {
    try {
      // NOTE: Should we consider this code and parse it instead?
      str = fs.readFileSync(str, 'utf8');
      return function() { return str; };
    } catch (e) {
      return noop;
    }
  }

  var tkey = info.name + '.' + key
    , header = 'var v, dyn = {}, stat = {}, stack = [], out = [];'
    , footer = ';return out.join("");'
    , code = header
    , val = str
    , buff = ''
    , cap
    , ch
    , fi
    , then
    , els
    , end;

  function read(regex, no) {
    cap = regex.exec(val);
    if (!cap) return;
    val = val.substring(cap[0].length);
    ch = cap[1];
    if (!no) clear();
    return cap;
  }

  function stmt(c) {
    if (code[code.length-1] === ',') {
      code = code.slice(0, -1);
    }
    code += c;
  }

  function expr(c) {
    code += c + ',';
  }

  function echo(c) {
    if (c === '""') return;
    expr('out.push(' + c + ')');
  }

  function print(c) {
    buff += c;
  }

  function clear() {
    if (buff) {
      echo(JSON.stringify(buff).replace(/\\u00([0-9a-fA-F]{2})/g, '\\x$1'));
      buff = '';
    }
  }

  while (val) {
    // Ignore newlines
    if (read(/^\n /, true)) {
      continue;
    }

    // '^A' -> ^A
    if (read(/^\^(.)/i, true)) {
      if (!(ch >= ' ' && ch <= '~')) {
        this._debug('%s: bad caret char.', tkey);
        // NOTE: ncurses appears to simply
        // continue in this situation, but
        // I could be wrong.
        print(cap[0]);
        continue;
      }
      if (ch === '?') {
        ch = '\x7f';
      } else {
        ch = ch.charCodeAt(0) & 31;
        if (ch === 0) ch = 128;
        ch = String.fromCharCode(ch);
      }
      print(ch);
      continue;
    }

    // 3 octal digits -> character
    if (read(/^\\([0-7]{3})/, true)) {
      print(String.fromCharCode(parseInt(ch, 8)));
      continue;
    }

    // '\e' -> ^[
    // '\n' -> \n
    // '\r' -> \r
    // '\0' -> \200 (special case)
    if (read(/^\\([eEnlrtbfs\^\\,:0]|.)/, true)) {
      switch (ch) {
        case 'e':
        case 'E':
          ch = '\x1b';
          break;
        case 'n':
          ch = '\n';
          break;
        case 'l':
          ch = '\x85';
          break;
        case 'r':
          ch = '\r';
          break;
        case 't':
          ch = '\t';
          break;
        case 'b':
          ch = '\x08';
          break;
        case 'f':
          ch = '\x0c';
          break;
        case 's':
          ch = ' ';
          break;
        case '^':
          ch = '^';
          break;
        case '\\':
          ch = '\\';
          break;
        case ',':
          ch = ',';
          break;
        case ':':
          ch = ':';
          break;
        case '0':
          ch = '\200';
          break;
        case 'a':
          ch = '\x07';
          break;
        default:
          this._debug('%s: bad backslash char.', tkey);
          ch = cap[0];
          break;
      }
      print(ch);
      continue;
    }

    // $<5> -> padding
    // e.g. flash_screen: '\u001b[?5h$<100/>\u001b[?5l',
    if (read(/^\$<(\d+)([*\/]{0,2})>/, true)) {
      if (this.padding) print(cap[0]);
      continue;
    }

    // %%   outputs `%'
    if (read(/^%%/, true)) {
      print('%');
      continue;
    }

    // %[[:]flags][width[.precision]][doxXs]
    //   as in printf, flags are [-+#] and space.  Use a `:' to allow the
    //   next character to be a `-' flag, avoiding interpreting "%-" as an
    //   operator.
    // %c   print pop() like %c in printf
    // Example from screen terminfo:
    //   S0: "\u001b(%p1%c"
    // %d   print pop()
    // "Print (e.g., "%d") is a special case."
    // %s   print pop() like %s in printf
    if (read(/^%((?::-|[+# ]){1,4})?(\d+(?:\.\d+)?)?([doxXsc])/)) {
      if (this.printf || cap[1] || cap[2] || ~'oxX'.indexOf(cap[3])) {
        echo('sprintf("'+ cap[0].replace(':-', '-') + '", stack.pop())');
      } else if (cap[3] === 'c') {
        echo('(v = stack.pop(), isFinite(v) '
          + '? String.fromCharCode(v || 0200) : "")');
      } else {
        echo('stack.pop()');
      }
      continue;
    }

    // %p[1-9]
    //   push i'th parameter
    if (read(/^%p([1-9])/)) {
      expr('(stack.push(v = params[' + (ch - 1) + ']), v)');
      continue;
    }

    // %P[a-z]
    //   set dynamic variable [a-z] to pop()
    if (read(/^%P([a-z])/)) {
      expr('dyn.' + ch + ' = stack.pop()');
      continue;
    }

    // %g[a-z]
    //   get dynamic variable [a-z] and push it
    if (read(/^%g([a-z])/)) {
      expr('(stack.push(dyn.' + ch + '), dyn.' + ch + ')');
      continue;
    }

    // %P[A-Z]
    //   set static variable [a-z] to pop()
    if (read(/^%P([A-Z])/)) {
      expr('stat.' + ch + ' = stack.pop()');
      continue;
    }

    // %g[A-Z]
    //   get static variable [a-z] and push it
    //   The  terms  "static"  and  "dynamic" are misleading.  Historically,
    //   these are simply two different sets of variables, whose values are
    //   not reset between calls to tparm.  However, that fact is not
    //   documented in other implementations.  Relying on it will adversely
    //   impact portability to other implementations.
    if (read(/^%g([A-Z])/)) {
      expr('(stack.push(v = stat.' + ch + '), v)');
      continue;
    }

    // %'c' char constant c
    // NOTE: These are stored as c chars, exemplified by:
    // cursor_address: "\u001b=%p1%' '%+%c%p2%' '%+%c"
    if (read(/^%'(.)'/)) {
      expr('(stack.push(v = ' + ch.charCodeAt(0) + '), v)');
      continue;
    }

    // %{nn}
    //   integer constant nn
    if (read(/^%\{(\d+)\}/)) {
      expr('(stack.push(v = ' + ch + '), v)');
      continue;
    }

    // %l   push strlen(pop)
    if (read(/^%l/)) {
      expr('(stack.push(v = (stack.pop() || "").length || 0), v)');
      continue;
    }

    // %+ %- %* %/ %m
    //   arithmetic (%m is mod): push(pop() op pop())
    // %& %| %^
    //   bit operations (AND, OR and exclusive-OR): push(pop() op pop())
    // %= %> %<
    //   logical operations: push(pop() op pop())
    if (read(/^%([+\-*\/m&|\^=><])/)) {
      if (ch === '=') ch = '===';
      else if (ch === 'm') ch = '%';
      expr('(v = stack.pop(),'
        + ' stack.push(v = (stack.pop() ' + ch + ' v) || 0),'
        + ' v)');
      continue;
    }

    // %A, %O
    //   logical AND and OR operations (for conditionals)
    if (read(/^%([AO])/)) {
      // Are we supposed to store the result on the stack?
      expr('(stack.push(v = (stack.pop() '
        + (ch === 'A' ? '&&' : '||')
        + ' stack.pop())), v)');
      continue;
    }

    // %! %~
    //   unary operations (logical and bit complement): push(op pop())
    if (read(/^%([!~])/)) {
      expr('(stack.push(v = ' + ch + 'stack.pop()), v)');
      continue;
    }

    // %i   add 1 to first two parameters (for ANSI terminals)
    if (read(/^%i/)) {
      // Are these supposed to go on the stack in certain situations?
      // ncurses doesn't seem to put them on the stack, but xterm.user6
      // seems to assume they're on the stack for some reason. Could
      // just be a bad terminfo string.
      // user6: "\u001b[%i%d;%dR" - possibly a termcap-style string.
      // expr('(params[0] |= 0, params[1] |= 0, params[0]++, params[1]++)');
      expr('(params[0]++, params[1]++)');
      continue;
    }

    // %? expr %t thenpart %e elsepart %;
    //   This forms an if-then-else.  The %e elsepart is optional.  Usually
    //   the %? expr part pushes a value onto the stack, and %t pops it from
    //   the stack, testing if it is nonzero (true).  If it is zero (false),
    //   control passes to the %e (else) part.
    //   It is possible to form else-if's a la Algol 68:
    //     %? c1 %t b1 %e c2 %t b2 %e c3 %t b3 %e c4 %t b4 %e %;
    //   where ci are conditions, bi are bodies.
    if (read(/^%\?/)) {
      end = -1;
      stmt(';if (');
      continue;
    }

    if (read(/^%t/)) {
      end = -1;
      // Technically this is supposed to pop everything off the stack that was
      // pushed onto the stack after the if statement, see man terminfo.
      // Right now, we don't pop anything off. This could cause compat issues.
      // Perhaps implement a "pushed" counter from the time the if statement
      // is added, to the time the then statement is added, and pop off
      // the appropriate number of elements.
      // while (pushed--) expr('stack.pop()');
      stmt(') {');
      continue;
    }

    // Terminfo does elseif's like
    // this: %?[expr]%t...%e[expr]%t...%;
    if (read(/^%e/)) {
      fi = val.indexOf('%?');
      then = val.indexOf('%t');
      els = val.indexOf('%e');
      end = val.indexOf('%;');
      if (end === -1) end = Infinity;
      if (then !== -1 && then < end
          && (fi === -1 || then < fi)
          && (els === -1 || then < els)) {
        stmt('} else if (');
      } else {
        stmt('} else {');
      }
      continue;
    }

    if (read(/^%;/)) {
      end = null;
      stmt('}');
      continue;
    }

    buff += val[0];
    val = val.substring(1);
  }

  // Clear the buffer of any remaining text.
  clear();

  // Some terminfos (I'm looking at you, atari-color), don't end an if
  // statement. It's assumed terminfo will automatically end it for
  // them, because they are a bunch of lazy bastards.
  if (end != null) {
    stmt('}');
  }

  // Add the footer.
  stmt(footer);

  // Optimize and cleanup generated code.
  v = code.slice(header.length, -footer.length);
  if (!v.length) {
    code = 'return "";';
  } else if (v = /^out\.push\(("(?:[^"]|\\")+")\)$/.exec(v)) {
    code = 'return ' + v[1] + ';';
  } else {
    // Turn `(stack.push(v = params[0]), v),out.push(stack.pop())`
    // into `out.push(params[0])`.
    code = code.replace(
      /\(stack\.push\(v = params\[(\d+)\]\), v\),out\.push\(stack\.pop\(\)\)/g,
      'out.push(params[$1])');

    // Remove unnecessary variable initializations.
    v = code.slice(header.length, -footer.length);
    if (!~v.indexOf('v = ')) code = code.replace('v, ', '');
    if (!~v.indexOf('dyn')) code = code.replace('dyn = {}, ', '');
    if (!~v.indexOf('stat')) code = code.replace('stat = {}, ', '');
    if (!~v.indexOf('stack')) code = code.replace('stack = [], ', '');

    // Turn `var out = [];out.push("foo"),` into `var out = ["foo"];`.
    code = code.replace(
      /out = \[\];out\.push\(("(?:[^"]|\\")+")\),/,
      'out = [$1];');
  }

  // Terminfos `wyse350-vb`, and `wy350-w`
  // seem to have a few broken strings.
  if (str === '\u001b%?') {
    code = 'return "\\x1b";';
  }

  if (this.debug) {
    v = code
      .replace(/\x1b/g, '\\x1b')
      .replace(/\r/g, '\\r')
      .replace(/\n/g, '\\n');
    process.stdout.write(v + '\n');
  }

  try {
    if (this.options.stringify && code.indexOf('return ') === 0) {
      return new Function('', code)();
    }
    return this.printf || ~code.indexOf('sprintf(')
      ? new Function('sprintf, params', code).bind(null, sprintf)
      : new Function('params', code);
  } catch (e) {
    console.error('');
    console.error('Error on %s:', tkey);
    console.error(JSON.stringify(str));
    console.error('');
    console.error(code.replace(/(,|;)/g, '$1\n'));
    e.stack = e.stack.replace(/\x1b/g, '\\x1b');
    throw e;
  }
};

// See: ~/ncurses/ncurses/tinfo/lib_tputs.c
Tput.prototype._print = function(code, print, done) {
  var print = print || write
    , done = done || noop
    , xon = !this.bools.needs_xon_xoff || this.bools.xon_xoff;

  if (!this.padding) {
    print(code);
    return done();
  }

  var parts = code.split(/(?=\$<[\d.]+[*\/]{0,2}>)/)
    , i = 0;

  (function next() {
    if (i === parts.length) {
      return done();
    }

    var part = parts[i++]
      , padding = /^\$<([\d.]+)([*\/]{0,2})>/.exec(part)
      , amount
      , suffix
      , affect;

    if (!padding) {
      print(part);
      return next();
    }

    part = part.substring(padding[0].length);
    amount = +padding[1];
    suffix = padding[2];

    // A `/'  suffix indicates  that  the  padding  is  mandatory and forces a
    // delay of the given number of milliseconds even on devices for which xon
    // is present to indicate flow control.
    if (xon && !~suffix.indexOf('/')) {
      print(part);
      return next();
    }

    // A `*' indicates that the padding required is proportional to the number
    // of lines affected by the operation, and  the amount  given  is the
    // per-affected-unit padding required.  (In the case of insert character,
    // the factor is still the number of lines affected.) Normally, padding is
    // advisory if the device has the xon capability; it is used for cost
    // computation but does not trigger delays.
    if (~suffix.indexOf('*')) {
      if (affect = /\x1b\[(\d+)[LM]/.exec(part)) {
        amount *= +affect[1];
      }
      // The above is a huge workaround. In reality, we need to compile
      // `_print` into the string functions and check the cap name and
      // params.
      // if (cap === 'insert_line' || cap === 'delete_line') {
      //   amount *= params[0];
      // }
      // if (cap === 'clear_screen') {
      //   amount *= process.stdout.rows;
      // }
    }

    return setTimeout(function() {
      print(part);
      return next();
    }, amount);
  })();
};

/**
 * Termcap
 */

Tput.cpaths = [
  process.env.TERMCAP || '',
  (process.env.TERMPATH || '').split(/[: ]/),
  (process.env.HOME || '') + '/.termcap',
  '/usr/share/misc/termcap',
  '/etc/termcap'
];

Tput.prototype.readTermcap = function(term) {
  var self = this
    , term = term || this.terminal
    , terms
    , term_
    , root
    , paths
    , i;

  // Termcap has a bunch of terminals usually stored in one file/string,
  // so we need to find the one containing our desired terminal.
  if (~term.indexOf(path.sep) && (terms = this._tryCap(path.resolve(term)))) {
    term_ = path.basename(term).split('.')[0];
    if (terms[process.env.TERM]) {
      term = process.env.TERM;
    } else if (terms[term_]) {
      term = term_;
    } else {
      term = Object.keys(terms)[0];
    }
  } else {
    paths = Tput.cpaths.slice();

    if (this.termcapFile) {
      paths.unshift(this.termcapFile);
    }

    paths.push(Tput.termcap);

    terms = this._tryCap(paths, term);
  }

  if (!terms) {
    throw new Error('Cannot find termcap for: ' + term);
  }

  root = terms[term];

  if (this.debug) {
    this._termcap = terms;
  }

  (function tc(term) {
    if (term && term.strings.tc) {
      root.inherits = root.inherits || [];
      root.inherits.push(term.strings.tc);

      var names = terms[term.strings.tc]
        ? terms[term.strings.tc].names
        : [term.strings.tc];

      self._debug('%s inherits from %s.',
        term.names.join('/'), names.join('/'));

      var inherit = tc(terms[term.strings.tc]);
      if (inherit) {
        ['bools', 'numbers', 'strings'].forEach(function(type) {
          merge(term[type], inherit[type]);
        });
      }
    }
    return term;
  })(root);

  // Translate termcap names to terminfo-style names.
  root = this.translateTermcap(root);

  return root;
};

Tput.prototype._tryCap = function(file, term) {
  if (!file) return;

  var terms
    , data
    , i;

  if (Array.isArray(file)) {
    for (i = 0; i < file.length; i++) {
      data = this._tryCap(file[i], term);
      if (data) return data;
    }
    return;
  }

  // If the termcap string starts with `/`,
  // ncurses considers it a filename.
  data = file[0] === '/'
    ? tryRead(file)
    : file;

  if (!data) return;

  terms = this.parseTermcap(data, file);

  if (term && !terms[term]) {
    return;
  }

  return terms;
};

/**
 * Termcap Parser
 *  http://en.wikipedia.org/wiki/Termcap
 *  http://www.gnu.org/software
 *    /termutils/manual/termcap-1.3/html_mono/termcap.html
 *  http://www.gnu.org/software
 *    /termutils/manual/termcap-1.3/html_mono/termcap.html#SEC17
 *  http://tldp.org/HOWTO/Text-Terminal-HOWTO.html#toc16
 *  man termcap
 */

// Example:
// vt102|dec vt102:\
//  :do=^J:co#80:li#24:cl=50\E[;H\E[2J:\
//  :le=^H:bs:cm=5\E[%i%d;%dH:nd=2\E[C:up=2\E[A:\
//  :ce=3\E[K:cd=50\E[J:so=2\E[7m:se=2\E[m:us=2\E[4m:ue=2\E[m:\
//  :md=2\E[1m:mr=2\E[7m:mb=2\E[5m:me=2\E[m:is=\E[1;24r\E[24;1H:\
//  :rs=\E>\E[?3l\E[?4l\E[?5l\E[?7h\E[?8h:ks=\E[?1h\E=:ke=\E[?1l\E>:\
//  :ku=\EOA:kd=\EOB:kr=\EOC:kl=\EOD:kb=^H:\
//  :ho=\E[H:k1=\EOP:k2=\EOQ:k3=\EOR:k4=\EOS:pt:sr=5\EM:vt#3:\
//  :sc=\E7:rc=\E8:cs=\E[%i%d;%dr:vs=\E[?7l:ve=\E[?7h:\
//  :mi:al=\E[L:dc=\E[P:dl=\E[M:ei=\E[4l:im=\E[4h:

Tput.prototype.parseTermcap = function(data, file) {
  var terms = {}
    , parts
    , term
    , entries
    , fields
    , field
    , names
    , i
    , j
    , k;

  // remove escaped newlines
  data = data.replace(/\\\n[ \t]*/g, '');

  // remove comments
  data = data.replace(/^#[^\n]+/gm, '');

  // split entries
  entries = data.trim().split(/\n+/);

  for (i = 0; i < entries.length; i++) {
    fields = entries[i].split(/:+/);
    for (j = 0; j < fields.length; j++) {
      field = fields[j].trim();
      if (!field) continue;

      if (j === 0) {
        names = field.split('|');
        term = {
          name: names[0],
          names: names,
          desc: names.pop(),
          file: ~file.indexOf(path.sep)
            ? path.resolve(file)
            : file,
          termcap: true
        };

        for (k = 0; k < names.length; k++) {
          terms[names[k]] = term;
        }

        term.bools = {};
        term.numbers = {};
        term.strings = {};

        continue;
      }

      if (~field.indexOf('=')) {
        parts = field.split('=');
        term.strings[parts[0]] = parts.slice(1).join('=');
      } else if (~field.indexOf('#')) {
        parts = field.split('#');
        term.numbers[parts[0]] = +parts.slice(1).join('#');
      } else {
        term.bools[field] = true;
      }
    }
  }

  return terms;
};

/**
 * Termcap Compiler
 *  man termcap
 */

Tput.prototype.translateTermcap = function(info) {
  var self = this
    , out = {};

  if (!info) return;

  this._debug(info);

  ['name', 'names', 'desc', 'file', 'termcap'].forEach(function(key) {
    out[key] = info[key];
  });

  // Separate aliases for termcap
  var map = (function() {
    var out = {};

    Object.keys(Tput.alias).forEach(function(key) {
      var aliases = Tput.alias[key];
      out[aliases.termcap] = key;
    });

    return out;
  })();

  // Translate termcap cap names to terminfo cap names.
  // e.g. `up` -> `cursor_up`
  ['bools', 'numbers', 'strings'].forEach(function(key) {
    out[key] = {};
    Object.keys(info[key]).forEach(function(cap) {
      if (key === 'strings') {
        info.strings[cap] = self._captoinfo(cap, info.strings[cap], 1);
      }
      if (map[cap]) {
        out[key][map[cap]] = info[key][cap];
      } else {
        // NOTE: Possibly include all termcap names
        // in a separate alias.js file. Some are
        // missing from the terminfo alias.js file
        // which is why we have to do this:
        // See: $ man termcap
        out[key][cap] = info[key][cap];
      }
    });
  });

  return out;
};

Tput.prototype.compileTermcap = function(term) {
  return this.compile(this.readTermcap(term));
};

Tput.prototype.injectTermcap = function(term) {
  return this.inject(this.compileTermcap(term));
};

/**
 * _nc_captoinfo - ported to javascript directly from ncurses.
 * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.
 * See: ~/ncurses/ncurses/tinfo/captoinfo.c
 *
 * Convert a termcap string to terminfo format.
 * 'cap' is the relevant terminfo capability index.
 * 's' is the string value of the capability.
 * 'parameterized' tells what type of translations to do:
 *    % translations if 1
 *    pad translations if >=0
 */

Tput.prototype._captoinfo = function(cap, s, parameterized) {
  var self = this;

  var capstart;

  if (parameterized == null) {
    parameterized = 0;
  }

  var MAX_PUSHED = 16
    , stack = [];

  var stackptr = 0
    , onstack = 0
    , seenm = 0
    , seenn = 0
    , seenr = 0
    , param = 1
    , i = 0
    , out = '';

  function warn() {
    var args = Array.prototype.slice.call(arguments);
    args[0] = 'captoinfo: ' + (args[0] || '');
    return self._debug.apply(self, args);
  }

  function isdigit(ch) {
    return ch >= '0' && ch <= '9';
  }

  function isgraph(ch) {
    return ch > ' ' && ch <= '~';
  }

  // convert a character to a terminfo push
  function cvtchar(sp) {
    var c = '\0'
      , len;

    var j = i;

    switch (sp[j]) {
      case '\\':
        switch (sp[++j]) {
          case '\'':
          case '$':
          case '\\':
          case '%':
            c = sp[j];
            len = 2;
            break;
          case '\0':
            c = '\\';
            len = 1;
            break;
          case '0':
          case '1':
          case '2':
          case '3':
            len = 1;
            while (isdigit(sp[j])) {
              c = String.fromCharCode(8 * c.charCodeAt(0)
                + (sp[j++].charCodeAt(0) - '0'.charCodeAt(0)));
              len++;
            }
            break;
          default:
            c = sp[j];
            len = 2;
            break;
        }
        break;
      case '^':
        c = String.fromCharCode(sp[++j].charCodeAt(0) & 0x1f);
        len = 2;
        break;
      default:
        c = sp[j];
        len = 1;
    }
    if (isgraph(c) && c !== ',' && c !== '\'' && c !== '\\' && c !== ':') {
      out += '%\'';
      out += c;
      out += '\'';
    } else {
      out += '%{';
      if (c.charCodeAt(0) > 99) {
        out += String.fromCharCode(
          (c.charCodeAt(0) / 100 | 0) + '0'.charCodeAt(0));
      }
      if (c.charCodeAt(0) > 9) {
        out += String.fromCharCode(
          (c.charCodeAt(0) / 10 | 0) % 10 + '0'.charCodeAt(0));
      }
      out += String.fromCharCode(
        c.charCodeAt(0) % 10 + '0'.charCodeAt(0));
      out += '}';
    }

    return len;
  }

  // push n copies of param on the terminfo stack if not already there
  function getparm(parm, n) {
    if (seenr) {
      if (parm === 1) {
        parm = 2;
      } else if (parm === 2) {
        parm = 1;
      }
    }

    if (onstack === parm) {
      if (n > 1) {
        warn('string may not be optimal');
        out += '%Pa';
        while (n--) {
          out += '%ga';
        }
      }
      return;
    }

    if (onstack !== 0) {
      push();
    }

    onstack = parm;

    while (n--) {
      out += '%p';
      out += String.fromCharCode('0'.charCodeAt(0) + parm);
    }

    if (seenn && parm < 3) {
      out += '%{96}%^';
    }

    if (seenm && parm < 3) {
      out += '%{127}%^';
    }
  }

  // push onstack on to the stack
  function push() {
    if (stackptr >= MAX_PUSHED) {
      warn('string too complex to convert');
    } else {
      stack[stackptr++] = onstack;
    }
  }

  // pop the top of the stack into onstack
  function pop() {
    if (stackptr === 0) {
      if (onstack === 0) {
        warn('I\'m confused');
      } else {
        onstack = 0;
      }
    } else {
      onstack = stack[--stackptr];
    }
    param++;
  }

  function see03() {
    getparm(param, 1);
    out += '%3d';
    pop();
  }

  function invalid() {
    out += '%';
    i--;
    warn('unknown %% code %s (%#x) in %s',
      JSON.stringify(s[i]), s[i].charCodeAt(0), cap);
  }

  // skip the initial padding (if we haven't been told not to)
  capstart = null;
  if (s == null) s = '';

  if (parameterized >= 0 && isdigit(s[i])) {
    for (capstart = i;; i++) {
      if (!(isdigit(s[i]) || s[i] === '*' || s[i] === '.')) {
        break;
      }
    }
  }

  while (s[i]) {
    switch (s[i]) {
      case '%':
        i++;
        if (parameterized < 1) {
          out += '%';
          break;
        }
        switch (s[i++]) {
          case '%':
            out += '%';
            break;
          case 'r':
            if (seenr++ === 1) {
              warn('saw %%r twice in %s', cap);
            }
            break;
          case 'm':
            if (seenm++ === 1) {
              warn('saw %%m twice in %s', cap);
            }
            break;
          case 'n':
            if (seenn++ === 1) {
              warn('saw %%n twice in %s', cap);
            }
            break;
          case 'i':
            out += '%i';
            break;
          case '6':
          case 'B':
            getparm(param, 1);
            out += '%{10}%/%{16}%*';
            getparm(param, 1);
            out += '%{10}%m%+';
            break;
          case '8':
          case 'D':
            getparm(param, 2);
            out += '%{2}%*%-';
            break;
          case '>':
            getparm(param, 2);
            // %?%{x}%>%t%{y}%+%;
            out += '%?';
            i += cvtchar(s);
            out += '%>%t';
            i += cvtchar(s);
            out += '%+%;';
            break;
          case 'a':
            if ((s[i] === '=' || s[i] === '+' || s[i] === '-'
                || s[i] === '*' || s[i] === '/')
                && (s[i + 1] === 'p' || s[i + 1] === 'c')
                && s[i + 2] !== '\0' && s[i + 2]) {
              var l;
              l = 2;
              if (s[i] !== '=') {
                getparm(param, 1);
              }
              if (s[i + 1] === 'p') {
                getparm(param + s[i + 2].charCodeAt(0) - '@'.charCodeAt(0), 1);
                if (param !== onstack) {
                  pop();
                  param--;
                }
                l++;
              } else {
                i += 2, l += cvtchar(s), i -= 2;
              }
              switch (s[i]) {
                case '+':
                  out += '%+';
                  break;
                case '-':
                  out += '%-';
                  break;
                case '*':
                  out += '%*';
                  break;
                case '/':
                  out += '%/';
                  break;
                case '=':
                  if (seenr) {
                    if (param === 1) {
                      onstack = 2;
                    } else if (param === 2) {
                      onstack = 1;
                    } else {
                      onstack = param;
                    }
                  } else {
                    onstack = param;
                  }
                  break;
              }
              i += l;
              break;
            }
            getparm(param, 1);
            i += cvtchar(s);
            out += '%+';
            break;
          case '+':
            getparm(param, 1);
            i += cvtchar(s);
            out += '%+%c';
            pop();
            break;
          case 's':
// #ifdef WATERLOO
//          i += cvtchar(s);
//          getparm(param, 1);
//          out += '%-';
// #else
            getparm(param, 1);
            out += '%s';
            pop();
// #endif /* WATERLOO */
            break;
          case '-':
            i += cvtchar(s);
            getparm(param, 1);
            out += '%-%c';
            pop();
            break;
          case '.':
            getparm(param, 1);
            out += '%c';
            pop();
            break;
          case '0': // not clear any of the historical termcaps did this
            if (s[i] === '3') {
              see03(); // goto
              break;
            } else if (s[i] !== '2') {
              invalid(); // goto
              break;
            }
            // FALLTHRU
          case '2':
            getparm(param, 1);
            out += '%2d';
            pop();
            break;
          case '3':
            see03();
            break;
          case 'd':
            getparm(param, 1);
            out += '%d';
            pop();
            break;
          case 'f':
            param++;
            break;
          case 'b':
            param--;
            break;
          case '\\':
            out += '%\\';
            break;
          default:
            invalid();
            break;
        }
        break;
// #ifdef REVISIBILIZE
//    case '\\':
//      out += s[i++];
//      out += s[i++];
//      break;
//    case '\n':
//      out += '\\n';
//      i++;
//      break;
//    case '\t':
//      out += '\\t';
//      i++;
//      break;
//    case '\r':
//      out += '\\r';
//      i++;
//      break;
//    case '\200':
//      out += '\\0';
//      i++;
//      break;
//    case '\f':
//      out += '\\f';
//      i++;
//      break;
//    case '\b':
//      out += '\\b';
//      i++;
//      break;
//    case ' ':
//      out += '\\s';
//      i++;
//      break;
//    case '^':
//      out += '\\^';
//      i++;
//      break;
//    case ':':
//      out += '\\:';
//      i++;
//      break;
//    case ',':
//      out += '\\,';
//      i++;
//      break;
//    default:
//      if (s[i] === '\033') {
//        out += '\\E';
//        i++;
//      } else if (s[i].charCodeAt(0) > 0 && s[i].charCodeAt(0) < 32) {
//        out += '^';
//        out += String.fromCharCode(s[i].charCodeAt(0) + '@'.charCodeAt(0));
//        i++;
//      } else if (s[i].charCodeAt(0) <= 0 || s[i].charCodeAt(0) >= 127) {
//        out += '\\';
//        out += String.fromCharCode(
//          ((s[i].charCodeAt(0) & 0300) >> 6) + '0'.charCodeAt(0));
//        out += String.fromCharCode(
//          ((s[i].charCodeAt(0) & 0070) >> 3) + '0'.charCodeAt(0));
//        out += String.fromCharCode(
//          (s[i].charCodeAt(0) & 0007) + '0'.charCodeAt(0));
//        i++;
//      } else {
//        out += s[i++];
//      }
//      break;
// #else
      default:
        out += s[i++];
        break;
// #endif
    }
  }

  // Now, if we stripped off some leading padding, add it at the end
  // of the string as mandatory padding.
  if (capstart != null) {
    out += '$<';
    for (i = capstart;; i++) {
      if (isdigit(s[i]) || s[i] === '*' || s[i] === '.') {
        out += s[i];
      } else {
        break;
      }
    }
    out += '/>';
  }

  if (s !== out) {
    warn('Translating %s from %s to %s.',
      cap, JSON.stringify(s), JSON.stringify(out));
  }

  return out;
};

/**
 * Compile All Terminfo
 */

Tput.prototype.getAll = function() {
  var dir = this._prefix()
    , list = asort(fs.readdirSync(dir))
    , infos = [];

  list.forEach(function(letter) {
    var terms = asort(fs.readdirSync(path.resolve(dir, letter)));
    infos.push.apply(infos, terms);
  });

  function asort(obj) {
    return obj.sort(function(a, b) {
      a = a.toLowerCase().charCodeAt(0);
      b = b.toLowerCase().charCodeAt(0);
      return a - b;
    });
  }

  return infos;
};

Tput.prototype.compileAll = function(start) {
  var self = this
    , all = {};

  this.getAll().forEach(function(name) {
    if (start && name !== start) {
      return;
    } else {
      start = null;
    }
    all[name] = self.compileTerminfo(name);
  });

  return all;
};

/**
 * Detect Features / Quirks
 */

Tput.prototype.detectFeatures = function(info) {
  var data = this.parseACS(info);
  info.features = {
    unicode: this.detectUnicode(info),
    brokenACS: this.detectBrokenACS(info),
    PCRomSet: this.detectPCRomSet(info),
    magicCookie: this.detectMagicCookie(info),
    padding: this.detectPadding(info),
    setbuf: this.detectSetbuf(info),
    acsc: data.acsc,
    acscr: data.acscr
  };
  return info.features;
};

Tput.prototype.detectUnicode = function() {
  var LANG = process.env.LANG
    + ':' + process.env.LANGUAGE
    + ':' + process.env.LC_ALL
    + ':' + process.env.LC_CTYPE;

  return /utf-?8/i.test(LANG);
};

// For some reason TERM=linux has smacs/rmacs, but it maps to `^[[11m`
// and it does not switch to the DEC SCLD character set. What the hell?
// xterm: \x1b(0, screen: \x0e, linux: \x1b[11m (doesn't work)
// `man console_codes` says:
// 11  select null mapping, set display control flag, reset tog‐
//     gle meta flag (ECMA-48 says "first alternate font").
// See ncurses:
// ~/ncurses/ncurses/base/lib_set_term.c
// ~/ncurses/ncurses/tinfo/lib_acs.c
// ~/ncurses/ncurses/tinfo/tinfo_driver.c
// ~/ncurses/ncurses/tinfo/lib_setup.c
Tput.prototype.detectBrokenACS = function(info) {
  // ncurses-compatible env variable.
  if (process.env.NCURSES_NO_UTF8_ACS != null) {
    return true;
  }

  // If the terminal supports unicode, we don't need ACS.
  if (info.numbers['U8'] >= 0) {
    return !!info.numbers['U8'];
  }

  // The linux console is just broken for some reason.
  // Apparently the Linux console does not support ACS,
  // but it does support the PC ROM character set.
  if (info.name === 'linux') {
    return true;
  }

  // PC alternate charset
  // if (acsc.indexOf('+\x10,\x11-\x18.\x190') === 0) {
  if (this.detectPCRomSet(info)) {
    return true;
  }

  // screen termcap is bugged?
  if (info.name.indexOf('screen') == 0
      && process.env.TERMCAP
      && ~process.env.TERMCAP.indexOf('screen')
      && ~process.env.TERMCAP.indexOf('hhII00')) {
    if (~info.strings.enter_alt_charset_mode.indexOf('\016')
        || ~info.strings.enter_alt_charset_mode.indexOf('\017')
        || ~info.strings.set_attributes.indexOf('\016')
        || ~info.strings.set_attributes.indexOf('\017')) {
      return true;
    }
  }

  return false;
};

// If enter_pc_charset is the same as enter_alt_charset,
// the terminal does not support SCLD as ACS.
// See: ~/ncurses/ncurses/tinfo/lib_acs.c
Tput.prototype.detectPCRomSet = function(info) {
  var s = info.strings;
  if (s.enter_pc_charset_mode && s.enter_alt_charset_mode
      && s.enter_pc_charset_mode === s.enter_alt_charset_mode
      && s.exit_pc_charset_mode === s.exit_alt_charset_mode) {
    return true;
  }
  return false;
};

Tput.prototype.detectMagicCookie = function(info) {
  return process.env.NCURSES_NO_MAGIC_COOKIE == null;
};

Tput.prototype.detectPadding = function(info) {
  return process.env.NCURSES_NO_PADDING == null;
};

Tput.prototype.detectSetbuf = function(info) {
  return process.env.NCURSES_NO_SETBUF == null;
};

Tput.prototype.parseACS = function(info) {
  var data = {};

  data.acsc = {};
  data.acscr = {};

  // Possibly just return an empty object, as done here, instead of
  // specifically saying ACS is "broken" above. This would be more
  // accurate to ncurses logic. But it doesn't really matter.
  if (this.detectPCRomSet(info)) {
    return data;
  }

  // See: ~/ncurses/ncurses/tinfo/lib_acs.c: L208
  Object.keys(Tput.acsc).forEach(function(ch) {
    var acs_chars = info.strings.acs_chars || ''
      , i = acs_chars.indexOf(ch)
      , next = acs_chars[i + 1];

    if (!next || i === -1 || !Tput.acsc[next]) {
      return;
    }

    data.acsc[ch] = Tput.acsc[next];
    data.acscr[Tput.acsc[next]] = ch;
  });

  return data;
};

/**
 * Helpers
 */

function noop() {
  return '';
}

noop.unsupported = true;

function merge(a, b) {
  Object.keys(b).forEach(function(key) {
    a[key] = b[key];
  });
  return a;
}

function write(data) {
  return process.stdout.write(data);
}

function tryRead(file) {
  if (Array.isArray(file)) {
    for (var i = 0; i < file.length; i++) {
      var data = tryRead(file[i]);
      if (data) return data;
    }
    return '';
  }
  if (!file) return '';
  file = path.resolve.apply(path, arguments);
  try {
    return fs.readFileSync(file, 'utf8');
  } catch (e) {
    return '';
  }
}

/**
 * sprintf
 *  http://www.cplusplus.com/reference/cstdio/printf/
 */

function sprintf(src) {
  var params = Array.prototype.slice.call(arguments, 1)
    , rule = /%([\-+# ]{1,4})?(\d+(?:\.\d+)?)?([doxXsc])/g
    , i = 0;

  return src.replace(rule, function(_, flag, width, type) {
    var flags = (flag || '').split('')
      , param = params[i] != null ? params[i] : ''
      , initial = param
      , width = +width
      , opt = {}
      , pre = '';

    i++;

    switch (type) {
      case 'd': // signed int
        param = (+param).toString(10);
        break;
      case 'o': // unsigned octal
        param = (+param).toString(8);
        break;
      case 'x': // unsigned hex int
        param = (+param).toString(16);
        break;
      case 'X': // unsigned hex int uppercase
        param = (+param).toString(16).toUppercase();
        break;
      case 's': // string
        break;
      case 'c': // char
        param = isFinite(param)
          ? String.fromCharCode(param || 0200)
          : '';
        break;
    }

    flags.forEach(function(flag) {
      switch (flag) {
        // left-justify by width
        case '-':
          opt.left = true;
          break;
        // always precede numbers with their signs
        case '+':
          opt.signs = true;
          break;
        // used with o, x, X - value is preceded with 0, 0x, or 0X respectively.
        // used with a, A, e, E, f, F, g, G - forces written output to contain
        // a decimal point even if no more digits follow
        case '#':
          opt.hexpoint = true;
          break;
        // if no sign is going to be written, black space in front of the value
        case ' ':
          opt.space = true;
          break;
      }
    });

    if (opt.signs) {
      if (+initial >= 0) {
        pre += '+';
      }
    }

    if (opt.space) {
      if (!opt.signs && +initial >= 0) {
        pre += ' ';
      }
    }

    if (opt.hexpoint) {
      switch (type) {
        case 'o': // unsigned octal
          pre += '0';
          break;
        case 'x': // unsigned hex int
          pre += '0x';
          break;
        case 'X': // unsigned hex int uppercase
          pre += '0X';
          break;
      }
    }

    if (opt.left) {
      if (width > (pre.length + param.length)) {
        width -= pre.length + param.length;
        pre = Array(width + 1).join(' ') + pre;
      }
    }

    return pre + param;
  });
}

/**
 * Aliases
 */

Tput._alias = require('./alias');

Tput.alias = {};

['bools', 'numbers', 'strings'].forEach(function(type) {
  Object.keys(Tput._alias[type]).forEach(function(key) {
    var aliases = Tput._alias[type][key];
    Tput.alias[key] = [aliases[0]];
    Tput.alias[key].terminfo = aliases[0];
    Tput.alias[key].termcap = aliases[1];
  });
});

// Bools
Tput.alias.no_esc_ctlc.push('beehive_glitch');
Tput.alias.dest_tabs_magic_smso.push('teleray_glitch');

// Numbers
Tput.alias.micro_col_size.push('micro_char_size');

/**
 * Feature Checking
 */

Tput.aliasMap = {};

Object.keys(Tput.alias).forEach(function(key) {
  Tput.aliasMap[key] = key;
  Tput.alias[key].forEach(function(k) {
    Tput.aliasMap[k] = key;
  });
});

Tput.prototype.has = function(name) {
  var name = Tput.aliasMap[name]
    , val = this.all[name];

  if (!name) return false;

  if (typeof val === 'number') {
    return val !== -1;
  }

  return !!val;
};

/**
 * Fallback Termcap Entry
 */

Tput.termcap = ''
  + 'vt102|dec vt102:'
  + ':do=^J:co#80:li#24:cl=50\\E[;H\\E[2J:'
  + ':le=^H:bs:cm=5\\E[%i%d;%dH:nd=2\\E[C:up=2\\E[A:'
  + ':ce=3\\E[K:cd=50\\E[J:so=2\\E[7m:se=2\\E[m:us=2\\E[4m:ue=2\\E[m:'
  + ':md=2\\E[1m:mr=2\\E[7m:mb=2\\E[5m:me=2\\E[m:is=\\E[1;24r\\E[24;1H:'
  + ':rs=\\E>\\E[?3l\\E[?4l\\E[?5l\\E[?7h\\E[?8h:ks=\\E[?1h\\E=:ke=\\E[?1l\\E>:'
  + ':ku=\\EOA:kd=\\EOB:kr=\\EOC:kl=\\EOD:kb=^H:\\\n'
  + ':ho=\\E[H:k1=\\EOP:k2=\\EOQ:k3=\\EOR:k4=\\EOS:pt:sr=5\\EM:vt#3:'
  + ':sc=\\E7:rc=\\E8:cs=\\E[%i%d;%dr:vs=\\E[?7l:ve=\\E[?7h:'
  + ':mi:al=\\E[L:dc=\\E[P:dl=\\E[M:ei=\\E[4l:im=\\E[4h:';

/**
 * Terminfo Data
 */

Tput.bools = [
  'auto_left_margin',
  'auto_right_margin',
  'no_esc_ctlc',
  'ceol_standout_glitch',
  'eat_newline_glitch',
  'erase_overstrike',
  'generic_type',
  'hard_copy',
  'has_meta_key',
  'has_status_line',
  'insert_null_glitch',
  'memory_above',
  'memory_below',
  'move_insert_mode',
  'move_standout_mode',
  'over_strike',
  'status_line_esc_ok',
  'dest_tabs_magic_smso',
  'tilde_glitch',
  'transparent_underline',
  'xon_xoff',
  'needs_xon_xoff',
  'prtr_silent',
  'hard_cursor',
  'non_rev_rmcup',
  'no_pad_char',
  'non_dest_scroll_region',
  'can_change',
  'back_color_erase',
  'hue_lightness_saturation',
  'col_addr_glitch',
  'cr_cancels_micro_mode',
  'has_print_wheel',
  'row_addr_glitch',
  'semi_auto_right_margin',
  'cpi_changes_res',
  'lpi_changes_res',

  // #ifdef __INTERNAL_CAPS_VISIBLE
  'backspaces_with_bs',
  'crt_no_scrolling',
  'no_correctly_working_cr',
  'gnu_has_meta_key',
  'linefeed_is_newline',
  'has_hardware_tabs',
  'return_does_clr_eol'
];

Tput.numbers = [
  'columns',
  'init_tabs',
  'lines',
  'lines_of_memory',
  'magic_cookie_glitch',
  'padding_baud_rate',
  'virtual_terminal',
  'width_status_line',
  'num_labels',
  'label_height',
  'label_width',
  'max_attributes',
  'maximum_windows',
  'max_colors',
  'max_pairs',
  'no_color_video',
  'buffer_capacity',
  'dot_vert_spacing',
  'dot_horz_spacing',
  'max_micro_address',
  'max_micro_jump',
  'micro_col_size',
  'micro_line_size',
  'number_of_pins',
  'output_res_char',
  'output_res_line',
  'output_res_horz_inch',
  'output_res_vert_inch',
  'print_rate',
  'wide_char_size',
  'buttons',
  'bit_image_entwining',
  'bit_image_type',

  // #ifdef __INTERNAL_CAPS_VISIBLE
  'magic_cookie_glitch_ul',
  'carriage_return_delay',
  'new_line_delay',
  'backspace_delay',
  'horizontal_tab_delay',
  'number_of_function_keys'
];

Tput.strings = [
  'back_tab',
  'bell',
  'carriage_return',
  'change_scroll_region',
  'clear_all_tabs',
  'clear_screen',
  'clr_eol',
  'clr_eos',
  'column_address',
  'command_character',
  'cursor_address',
  'cursor_down',
  'cursor_home',
  'cursor_invisible',
  'cursor_left',
  'cursor_mem_address',
  'cursor_normal',
  'cursor_right',
  'cursor_to_ll',
  'cursor_up',
  'cursor_visible',
  'delete_character',
  'delete_line',
  'dis_status_line',
  'down_half_line',
  'enter_alt_charset_mode',
  'enter_blink_mode',
  'enter_bold_mode',
  'enter_ca_mode',
  'enter_delete_mode',
  'enter_dim_mode',
  'enter_insert_mode',
  'enter_secure_mode',
  'enter_protected_mode',
  'enter_reverse_mode',
  'enter_standout_mode',
  'enter_underline_mode',
  'erase_chars',
  'exit_alt_charset_mode',
  'exit_attribute_mode',
  'exit_ca_mode',
  'exit_delete_mode',
  'exit_insert_mode',
  'exit_standout_mode',
  'exit_underline_mode',
  'flash_screen',
  'form_feed',
  'from_status_line',
  'init_1string',
  'init_2string',
  'init_3string',
  'init_file',
  'insert_character',
  'insert_line',
  'insert_padding',
  'key_backspace',
  'key_catab',
  'key_clear',
  'key_ctab',
  'key_dc',
  'key_dl',
  'key_down',
  'key_eic',
  'key_eol',
  'key_eos',
  'key_f0',
  'key_f1',
  'key_f10',
  'key_f2',
  'key_f3',
  'key_f4',
  'key_f5',
  'key_f6',
  'key_f7',
  'key_f8',
  'key_f9',
  'key_home',
  'key_ic',
  'key_il',
  'key_left',
  'key_ll',
  'key_npage',
  'key_ppage',
  'key_right',
  'key_sf',
  'key_sr',
  'key_stab',
  'key_up',
  'keypad_local',
  'keypad_xmit',
  'lab_f0',
  'lab_f1',
  'lab_f10',
  'lab_f2',
  'lab_f3',
  'lab_f4',
  'lab_f5',
  'lab_f6',
  'lab_f7',
  'lab_f8',
  'lab_f9',
  'meta_off',
  'meta_on',
  'newline',
  'pad_char',
  'parm_dch',
  'parm_delete_line',
  'parm_down_cursor',
  'parm_ich',
  'parm_index',
  'parm_insert_line',
  'parm_left_cursor',
  'parm_right_cursor',
  'parm_rindex',
  'parm_up_cursor',
  'pkey_key',
  'pkey_local',
  'pkey_xmit',
  'print_screen',
  'prtr_off',
  'prtr_on',
  'repeat_char',
  'reset_1string',
  'reset_2string',
  'reset_3string',
  'reset_file',
  'restore_cursor',
  'row_address',
  'save_cursor',
  'scroll_forward',
  'scroll_reverse',
  'set_attributes',
  'set_tab',
  'set_window',
  'tab',
  'to_status_line',
  'underline_char',
  'up_half_line',
  'init_prog',
  'key_a1',
  'key_a3',
  'key_b2',
  'key_c1',
  'key_c3',
  'prtr_non',
  'char_padding',
  'acs_chars',
  'plab_norm',
  'key_btab',
  'enter_xon_mode',
  'exit_xon_mode',
  'enter_am_mode',
  'exit_am_mode',
  'xon_character',
  'xoff_character',
  'ena_acs',
  'label_on',
  'label_off',
  'key_beg',
  'key_cancel',
  'key_close',
  'key_command',
  'key_copy',
  'key_create',
  'key_end',
  'key_enter',
  'key_exit',
  'key_find',
  'key_help',
  'key_mark',
  'key_message',
  'key_move',
  'key_next',
  'key_open',
  'key_options',
  'key_previous',
  'key_print',
  'key_redo',
  'key_reference',
  'key_refresh',
  'key_replace',
  'key_restart',
  'key_resume',
  'key_save',
  'key_suspend',
  'key_undo',
  'key_sbeg',
  'key_scancel',
  'key_scommand',
  'key_scopy',
  'key_screate',
  'key_sdc',
  'key_sdl',
  'key_select',
  'key_send',
  'key_seol',
  'key_sexit',
  'key_sfind',
  'key_shelp',
  'key_shome',
  'key_sic',
  'key_sleft',
  'key_smessage',
  'key_smove',
  'key_snext',
  'key_soptions',
  'key_sprevious',
  'key_sprint',
  'key_sredo',
  'key_sreplace',
  'key_sright',
  'key_srsume',
  'key_ssave',
  'key_ssuspend',
  'key_sundo',
  'req_for_input',
  'key_f11',
  'key_f12',
  'key_f13',
  'key_f14',
  'key_f15',
  'key_f16',
  'key_f17',
  'key_f18',
  'key_f19',
  'key_f20',
  'key_f21',
  'key_f22',
  'key_f23',
  'key_f24',
  'key_f25',
  'key_f26',
  'key_f27',
  'key_f28',
  'key_f29',
  'key_f30',
  'key_f31',
  'key_f32',
  'key_f33',
  'key_f34',
  'key_f35',
  'key_f36',
  'key_f37',
  'key_f38',
  'key_f39',
  'key_f40',
  'key_f41',
  'key_f42',
  'key_f43',
  'key_f44',
  'key_f45',
  'key_f46',
  'key_f47',
  'key_f48',
  'key_f49',
  'key_f50',
  'key_f51',
  'key_f52',
  'key_f53',
  'key_f54',
  'key_f55',
  'key_f56',
  'key_f57',
  'key_f58',
  'key_f59',
  'key_f60',
  'key_f61',
  'key_f62',
  'key_f63',
  'clr_bol',
  'clear_margins',
  'set_left_margin',
  'set_right_margin',
  'label_format',
  'set_clock',
  'display_clock',
  'remove_clock',
  'create_window',
  'goto_window',
  'hangup',
  'dial_phone',
  'quick_dial',
  'tone',
  'pulse',
  'flash_hook',
  'fixed_pause',
  'wait_tone',
  'user0',
  'user1',
  'user2',
  'user3',
  'user4',
  'user5',
  'user6',
  'user7',
  'user8',
  'user9',
  'orig_pair',
  'orig_colors',
  'initialize_color',
  'initialize_pair',
  'set_color_pair',
  'set_foreground',
  'set_background',
  'change_char_pitch',
  'change_line_pitch',
  'change_res_horz',
  'change_res_vert',
  'define_char',
  'enter_doublewide_mode',
  'enter_draft_quality',
  'enter_italics_mode',
  'enter_leftward_mode',
  'enter_micro_mode',
  'enter_near_letter_quality',
  'enter_normal_quality',
  'enter_shadow_mode',
  'enter_subscript_mode',
  'enter_superscript_mode',
  'enter_upward_mode',
  'exit_doublewide_mode',
  'exit_italics_mode',
  'exit_leftward_mode',
  'exit_micro_mode',
  'exit_shadow_mode',
  'exit_subscript_mode',
  'exit_superscript_mode',
  'exit_upward_mode',
  'micro_column_address',
  'micro_down',
  'micro_left',
  'micro_right',
  'micro_row_address',
  'micro_up',
  'order_of_pins',
  'parm_down_micro',
  'parm_left_micro',
  'parm_right_micro',
  'parm_up_micro',
  'select_char_set',
  'set_bottom_margin',
  'set_bottom_margin_parm',
  'set_left_margin_parm',
  'set_right_margin_parm',
  'set_top_margin',
  'set_top_margin_parm',
  'start_bit_image',
  'start_char_set_def',
  'stop_bit_image',
  'stop_char_set_def',
  'subscript_characters',
  'superscript_characters',
  'these_cause_cr',
  'zero_motion',
  'char_set_names',
  'key_mouse',
  'mouse_info',
  'req_mouse_pos',
  'get_mouse',
  'set_a_foreground',
  'set_a_background',
  'pkey_plab',
  'device_type',
  'code_set_init',
  'set0_des_seq',
  'set1_des_seq',
  'set2_des_seq',
  'set3_des_seq',
  'set_lr_margin',
  'set_tb_margin',
  'bit_image_repeat',
  'bit_image_newline',
  'bit_image_carriage_return',
  'color_names',
  'define_bit_image_region',
  'end_bit_image_region',
  'set_color_band',
  'set_page_length',
  'display_pc_char',
  'enter_pc_charset_mode',
  'exit_pc_charset_mode',
  'enter_scancode_mode',
  'exit_scancode_mode',
  'pc_term_options',
  'scancode_escape',
  'alt_scancode_esc',
  'enter_horizontal_hl_mode',
  'enter_left_hl_mode',
  'enter_low_hl_mode',
  'enter_right_hl_mode',
  'enter_top_hl_mode',
  'enter_vertical_hl_mode',
  'set_a_attributes',
  'set_pglen_inch',

  // #ifdef __INTERNAL_CAPS_VISIBLE
  'termcap_init2',
  'termcap_reset',
  'linefeed_if_not_lf',
  'backspace_if_not_bs',
  'other_non_function_keys',
  'arrow_key_map',
  'acs_ulcorner',
  'acs_llcorner',
  'acs_urcorner',
  'acs_lrcorner',
  'acs_ltee',
  'acs_rtee',
  'acs_btee',
  'acs_ttee',
  'acs_hline',
  'acs_vline',
  'acs_plus',
  'memory_lock',
  'memory_unlock',
  'box_chars_1'
];

// DEC Special Character and Line Drawing Set.
// Taken from tty.js.
Tput.acsc = {    // (0
  '`': '\u25c6', // '◆'
  'a': '\u2592', // '▒'
  'b': '\u0009', // '\t'
  'c': '\u000c', // '\f'
  'd': '\u000d', // '\r'
  'e': '\u000a', // '\n'
  'f': '\u00b0', // '°'
  'g': '\u00b1', // '±'
  'h': '\u2424', // '\u2424' (NL)
  'i': '\u000b', // '\v'
  'j': '\u2518', // '┘'
  'k': '\u2510', // '┐'
  'l': '\u250c', // '┌'
  'm': '\u2514', // '└'
  'n': '\u253c', // '┼'
  'o': '\u23ba', // '⎺'
  'p': '\u23bb', // '⎻'
  'q': '\u2500', // '─'
  'r': '\u23bc', // '⎼'
  's': '\u23bd', // '⎽'
  't': '\u251c', // '├'
  'u': '\u2524', // '┤'
  'v': '\u2534', // '┴'
  'w': '\u252c', // '┬'
  'x': '\u2502', // '│'
  'y': '\u2264', // '≤'
  'z': '\u2265', // '≥'
  '{': '\u03c0', // 'π'
  '|': '\u2260', // '≠'
  '}': '\u00a3', // '£'
  '~': '\u00b7'  // '·'
};

// Convert ACS unicode characters to the
// most similar-looking ascii characters.
Tput.utoa = Tput.prototype.utoa = {
  '\u25c6': '*', // '◆'
  '\u2592': ' ', // '▒'
  // '\u0009': '\t', // '\t'
  // '\u000c': '\f', // '\f'
  // '\u000d': '\r', // '\r'
  // '\u000a': '\n', // '\n'
  '\u00b0': '*', // '°'
  '\u00b1': '+', // '±'
  '\u2424': '\n', // '\u2424' (NL)
  // '\u000b': '\v', // '\v'
  '\u2518': '+', // '┘'
  '\u2510': '+', // '┐'
  '\u250c': '+', // '┌'
  '\u2514': '+', // '└'
  '\u253c': '+', // '┼'
  '\u23ba': '-', // '⎺'
  '\u23bb': '-', // '⎻'
  '\u2500': '-', // '─'
  '\u23bc': '-', // '⎼'
  '\u23bd': '_', // '⎽'
  '\u251c': '+', // '├'
  '\u2524': '+', // '┤'
  '\u2534': '+', // '┴'
  '\u252c': '+', // '┬'
  '\u2502': '|', // '│'
  '\u2264': '<', // '≤'
  '\u2265': '>', // '≥'
  '\u03c0': '?', // 'π'
  '\u2260': '=', // '≠'
  '\u00a3': '?', // '£'
  '\u00b7': '*'  // '·'
};

/**
 * Expose
 */

exports = Tput;
exports.sprintf = sprintf;
exports.merge = merge;
exports.tryRead = tryRead;

module.exports = exports;