What do I need to know about file permissions and “chmod”?
Unix systems are designed for multiple users, and include provision for protecting your work from unauthorised access by other users of the system. The file permissions determine who is permitted to do what with your programs, data, and directories. The command that sets file permissions is chmod. Web servers typically run as user “nobody”. That means that, setting aside serious bugs (such as those in certain versions of the Frontpage extensions), your files are absolutely secure from damage through the webserver. It also means that you may have to make explicit changes to enable the server to access them in a CGI context. There are two ways to run CGI: – by default they run as the webserver user (nobody) For most purposes this is safest, as your programs and data are protected by the operating system from unauthorised access through possible bugs in your CGI. However, when the CGI has to write to a file, that file must be writable to every web user on the system, and is therefore comp
