implementation seems to work but no tests yet

README.markdown

@@ -7,16 +7,15 @@ except you can pass in the file to compute paths relatively to along with your
 own `require.paths` without updating the global copy (which doesn't even work in
 node `>=0.5`).
 
-example
-=======
-
 methods
 =======
 
-resolve(pkg, opts={paths:[],path:__filename})
----------------------------------------------
+var resolve = require('resolve');
+
+resolve.sync(pkg, opts={paths:[],path:__filename})
+--------------------------------------------------
 
-Search for the package/filename `pkg`
+Synchronously search for the package/filename string `pkg`
 according to the [`require.resolve()`
 algorithm](http://nodejs.org/docs/v0.4.8/api/all.html#all_Together...)
 for `X=pkg` and `Y=opts.path`.

index.js

@@ -0,0 +1,77 @@
+var fs = require('fs');
+var path = require('path');
+
+// http://nodejs.org/docs/v0.4.8/api/all.html#all_Together...
+
+var core = [ 'assert', 'buffer', 'child_process', 'crypto', 'dgram', 'dns',
+    'events', 'fs', 'http', 'https', 'net', 'os', 'path', 'querystring', 'repl',
+    'stream', 'sys', 'tls', 'tty', 'url', 'util', 'vm'
+].reduce(function (acc, x) { acc[x] = true; return acc }, {});
+
+exports.sync = function (x, opts) {
+    if (core[x]) return x;
+
+    if (!opts) opts = {};
+    var y = opts.path || require.cache[__filename].parent.filename;
+
+    if (x.match(/^(?:\.\/|\/|\.\.\/)/)) {
+        var m = loadAsFileSync(y + x) || loadAsDirectorySync(y + x);
+        if (m) return m;
+    }
+
+    var n = loadNodeModulesSync(x, path.dirname(y));
+    if (n) return n;
+
+    throw new Error("Cannot find module '" + x + "'");
+}
+
+function loadAsFileSync (x) {
+    if (path.existsSync(x) && fs.statSync(x).isFile()) {
+        return x;
+    }
+    else if (path.existsSync(x + '.js') && fs.statSync(x + '.js').isFile()) {
+        return x + '.js';
+    }
+}
+
+function loadAsDirectorySync (x) {
+    var pkgfile = x + '/package.json';
+    if (path.existsSync(pkgfile) && fs.statSync(pkgfile).isFile()) {
+        var body = fs.readFileSync(pkgfile, 'utf8');
+        try {
+            var pkg = JSON.parse(body);
+            if (pkg.main) {
+                var m = loadAsFileSync(path.resolve(x, pkg.main));
+                if (m) return m;
+            }
+        }
+        catch (err) {}
+    }
+
+    return loadAsFileSync(x + '/index');
+}
+
+function loadNodeModulesSync (x, start) {
+    var dirs = nodeModulesPathsSync(start);
+    for (var i = 0; i < dirs.length; i++) {
+        var dir = dirs[i];
+        var m = loadAsFileSync(dir + '/' + x);
+        if (m) return m;
+        var n = loadAsDirectorySync(dir + '/' + x);
+        if (n) return n;
+    }
+}
+
+function nodeModulesPathsSync (start) {
+    var parts = start.split(/\/+/);
+    var root = parts.indexOf('node_modules');
+    if (root < 0) root = 0;
+
+    var dirs = [];
+    for (var i = parts.length - 1; i >= root; i--) {
+        if (parts[i] === 'node_modules') continue;
+        var dir = parts.slice(0, i + 1).join('/') + '/node_modules';
+        dirs.push(dir);
+    }
+    return dirs;
+}