Linux user group folder permissions

Question

I have a basic linux file permissions question:

I have a folder named test:

$ ls -la
drwxr-xr-x  5 root root    4096 2010-10-25 17:11 .
drwxr-xr-x 17 root root    4096 2010-10-25 16:53 ..
drw-rwS---  3 root codedev 4096 2010-10-25 17:11 test

In this folder (test) I want all users that are members of the group codedev to have read and write access, even to those files (inside test) that other users has created.

I have a testuser:

$ groups testuser 
testuser : testuser codedev

Why can't the user testuser cd into the directory test? How should I do the make this work?

Answer 1

In order to cd to a directory the user needs execute permission on the directory too, either by dint of ownership, or at the group, or world/other level.

Answer 2

Your directory is setgid, but not group executable.

If you want all users of the group to have read/write access as well, you'll need to make sure new files are created with group write permission. The easiest way to do that is to set the umask to 0775.