convert.js

var fs = require('fs');
var jsonfile  = require('jsonfile');
var readline  = require('readline');

var file = './cities.json';
var cities = [], i = 0, city;

readline.createInterface({
  input: fs.createReadStream('./cities1000.txt'),
  output: process.stdout,
  terminal: false
}).on('line', function(line) {
  city = line.split("\t");
  if (i !== 0) {
    // geonameid         : integer id of record in geonames database
    // name              : name of geographical point (utf8) varchar(200)
    // asciiname         : name of geographical point in plain ascii characters, varchar(200)
    // alternatenames    : alternatenames, comma separated, ascii names automatically transliterated, convenience attribute from alternatename table, varchar(10000)
    // latitude          : latitude in decimal degrees (wgs84)
    // longitude         : longitude in decimal degrees (wgs84)
    // feature class     : see http://www.geonames.org/export/codes.html, char(1)
    // feature code      : see http://www.geonames.org/export/codes.html, varchar(10)
    // country code      : ISO-3166 2-letter country code, 2 characters
    // cc2               : alternate country codes, comma separated, ISO-3166 2-letter country code, 200 characters
    // admin1 code       : fipscode (subject to change to iso code), see exceptions below, see file admin1Codes.txt for display names of this code; varchar(20)
    // admin2 code       : code for the second administrative division, a county in the US, see file admin2Codes.txt; varchar(80)
    // admin3 code       : code for third level administrative division, varchar(20)
    // admin4 code       : code for fourth level administrative division, varchar(20)
    // population        : bigint (8 byte int)
    // elevation         : in meters, integer
    // dem               : digital elevation model, srtm3 or gtopo30, average elevation of 3''x3'' (ca 90mx90m) or 30''x30'' (ca 900mx900m) area in meters, integer. srtm processed by cgiar/ciat.
    // timezone          : the iana timezone id (see file timeZone.txt) varchar(40)
    // modification date : date of last modification in yyyy-MM-dd format
    cities.push({
      country: city[8],
      name: city[1].replace('"', '').replace('"', ''),
      lat: city[4],
      lng: city[5]
    });
  }
  i++;
}).on('close', function() {
  jsonfile.writeFile(file, cities, {spaces: 2}, function (err) {
    if (err) {
      console.error(err)
    }
  })
});