You can easily change the sharing and access permissions of any shared file or folder in Google Drive with the help of Google Apps Script.
The following Google Script sets auto-expiration dates for shared links and makes the folder /file “Private” after the expiration date.
var EXPIRY_TIME = "2014-05-01 23:42"; function autoExpire() { var id, asset, i, email, users; // The URL of the Google Drive file or folder var URL = "https://drive.google.com/folderview?id=0B4fk8L6brI_ednJaa052"; try { // Extract the File or Folder ID from the Drive URL var id = URL.match(/[-\w]{25,}/); if (id) { asset = DriveApp.getFileById(id) ? DriveApp.getFileById(id) : DriveApp.getFolderById(id); if (asset) { // Make the folder / file Private asset.setSharing(DriveApp.Access.ANYONE, DriveApp.Permission.NONE); asset.setSharing(DriveApp.Access.ANYONE_WITH_LINK, DriveApp.Permission.NONE); // Remove all users who have edit permissions users = asset.getEditors(); for (i in users) { email = users[i].getEmail(); if (email != "") { asset.removeEditor(email); } } // Remove all users who have view permssions users = asset.getViewers(); for (i in users) { email = users[i].getEmail(); if (email != "") { asset.removeViewer(email); } } } } } catch (e) { Logger.log(e.toString()); } } function Start() { var triggers = ScriptApp.getProjectTriggers(); for (var i in triggers) { ScriptApp.deleteTrigger(triggers[i]); } var time = EXPIRY_TIME; // Run the auto-expiry script at this date and time var expireAt = new Date(time.substr(0,4), time.substr(5,2)-1, time.substr(8,2), time.substr(11,2), time.substr(14,2)); if ( !isNaN ( expireAt.getTime() ) ) { ScriptApp.newTrigger("autoExpire").timeBased().at(expireAt).create(); } }