extract id from file content

Author: zhaili

lib/file.js

@@ -172,6 +172,15 @@ file.meta = function(filename) {
     }
   });
 
+  const line2 = this.data(filename).split('\n')
+    .find(x => x.indexOf(' @lc ') >= 0) || '';
+  line2.split(' ').forEach(function(x) {
+    const v = x.split('=');
+    if (v.length == 2) {
+      if (v[0]==='id') m.id = v[1].trim();
+    }
+  });
+
   // otherwise, look into file name
   if (!m.id || !m.lang) {
     const olddata = this.metaByName(filename);