+ 0 Votes Here is a link to an explanation of chmod (change mode) wizard57m-cnet March 10, 2013 at 3:07am PST http://en.wikipedia.org/wiki/Chmod I'm not exactly sure what you are attempting to do, so maybe this general explanation will help. In your example, chmod 0755 testfile made the file named testfile executable with full access by all users. You mentioned using Ubuntu, I'm not well versed in this distribution, but thankfully shell commands are usually the same across all distributions. What file manager does Ubuntu have now? PCManFM? Dolphin? Anyway, it might be easier to use the file manager you have installed, right click on the file and choose properties... most file managers have hooks to the shell commands to modify file attributes.