index.js

var osmium = require('osmium');

if (process.stdin.isTTY) {
    if (process.argv[2] === undefined) {
        return console.log('specify a file: `node relevant.js [file].osc` or a list of files: `ls *.osc | node relevant.js`');
    }
    console.log(process.argv[2]);
    relevant(process.argv[2]);
} else {
    process.stdin.on('readable', function() {
        var buf = process.stdin.read();
        if (buf === null) return;
        buf.toString().split('\n').forEach(function(file) {
            if (file.length) relevant(file);
        });
    });
}

function relevant(file) {
    var reader = new osmium.Reader(file, {
        'node': true,
        'way': true
    });

    var handler = new osmium.Handler();
    // handler.options({'tagged_nodes_only': true});

    handler.on('node', function(node) {
        // console.log(node);
    });

    handler.on('way', function(way) {
        console.log(way);
    });

    // reader.apply(handler);
    osmium.apply(reader, handler, new osmium.LocationHandler('disk'));
}

osmium.js

var osmium = require('osmium');
    levelup = require('levelup');

var db = levelup('./' + (process.argv[3] || 'test.ldb'));
var count = 0;
var batch = [];
var batchSize = 100000;

var reader = new osmium.Reader(process.argv[2], {
    'node': true,
    'way': true
});

function nextBuffer() {
    var buffer = reader.read();
    if (!buffer) return pushBatch(batch);

    while (object = buffer.next()) {
        var type = ('nodes_count' in object) ? 'w' : 'n';
        batch.push({
            type: 'put',
            key: type + object.id,
            value: JSON.stringify(object)
        });
    }

    if (batch.length > batchSize) {
        pushBatch(batch, nextBuffer);
    } else {
        nextBuffer();
    }

    count++;
}

function pushBatch(array, callback) {
    db.batch(array, function(err) {
        if (err) return console.log(err);
        batch = [];
        return callback ? callback() : false;
    });
}

nextBuffer();

package.json

{
  "name": "openstreetreports",
  "version": "0.0.0",
  "description": "",
  "main": "",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "BSD",
  "dependencies": {
    "leveldown": "^0.10.1",
    "levelup": "^0.19.0",
    "osmium": "^0.2.0"
  }
}