By default, files in your home directory can be accessed by other users. Files in your other directories can be accessed only by yourself. (To understand why, see the umask manpage.)
The following are instructions for allowing another user to access the files within some directory.
The members of the group will be all the other users that should be able to access the files.
To create UNIX group, do:
group
You are now within the group interactive environment. To create a group named myproj, enter:
create myproj
To add user with login mypal to the group, enter:
add mypal
To exit the group interactive environment, enter:
exit
The new UNIX group will be effective within five minutes. Wait for five minutes and open a new shell.
To change the group owner of directory mydir (and all its files), do
chgrp -R myproj mydirectory
To grant read-access to mydir (and all its files) to the members of the group, do:
find mydir -type f -exec chmod g+r {} \;
find mydir -type d -exec chmod g+rx {} \;
Alternatively, to grant read- and write-access to mydir (and all its files) to the members of the group, do:
find mydir -type f -exec chmod g+rw {} \;
find mydir -type d -exec chmod g+rwx {} \;
Repeat the commands if you create a new file and/or directory under myproj. Alternatively, do:
newgrp myproj
umask 002
before starting to work. This ensures that any file or directory that you create will be group-writable.
Note: It is generally not a good idea that files should be writable by more than one user
For further information, see the relevant manpages.
Alternatively, use a version control system such as CVS, SubVersion or GIT.