Not sure how much this will help, but here's a (quick) rundown on Unix permissions (Note, I can't do anything Mac-specific yet, as I'm still waiting for mine to come in):
Every file is owned by both a user, and a group, usually following the idea of "admin.root" where "admin" is the user, and "root" is the group. To change this, use the "chown <user>.<group> <file/folder>" from command line. The user specified does not have to belong to the specified group.
Next, we have permissions:
All files & folders have permissions for the user who owns it, the group it belongs to, and everyone else. (See above for user & group) In these sets, we have 3 types: read, write, execute.
Code:
User | Group | Others
Read Write Execute | Read Write Execute | Read Write Execute
The command to change these is "chmod <permissions> <file/folder>".
Now, here, the permissions part of the command gts a wee bit complex, but here's a simple breakdown:
"chmod 755 file.ext" would be changing the permissions of "file.ext" to User can read, write, execute (rwx), group is read and execute (r-x), and others can read & execute (r-x).
To make the rest of this clear, this would therefore follow the pattern of:
rwxr-xr-x
if you notice, there are 3 settings for the 3 groups, therefore 9 options total, as there would be 9 letters in the pattern above (hyphens mean that that user cannot do the specified action).
Now, with the 3 numbers in the 755, here is the breakdown (If you know binary, it makes it a lot easier to understand):
Remember that these are all following the idea of rwx
Code:
0 ---
1 --x
2 -w-
3 -wx
4 r--
5 r-x
6 rw-
7 rwx
Now, remember that for nearly any command, you should be able to read the man page on it ("man <command in question>") which will go into more detail, and give you more options for them.
I hope this makes sense. If it doesn't just ask me about it.
Oh, and I hope that none of the Unix-knowing people here comment on my technical omissions (ie: Directory instead of folder, and that directories are, technically, files)