IT:AD:NET:HowTo:Security:Concepts:UNIX
- User:
- Name:Nick
- Name:WWW
- Group:
- Set of Priveleges
- Name:Perlfect
- Permissions:
- Read, Write, Execute
- Ownership:
- Every Item has an Owner User
- Every Item has an Owner Group
- Every Item has an All (neither Owner User or Owner Group)
- Therefore, for every item, one of the following can apply:
- Nick is the owner
- Nick belongs to the group that owns the file
- Nick is neither the owner, or belongs to a group that owns the file.
- rwxr-xr-x 1 nick users [= Owner(Nick):rwx, OwnerGroup(users):r-x, All:r-x
drwxr-xr-x 1 nick users [= Owner(Nick):rwx, OwnerGroup(users):r-x, All:r-x
- Directories:
- If it has a d prefix , it's for directories, and meaning changes a bit.
- read = list contents
- write = add items
- execute = user can cd into the directory.
- Use chmod:
- set permissions by target
- u: owner
- g: group
- o: other (neither u or g)
- a: all
Example:
$ ls -l socktest.pl -rwxr-xr-x 1 nick users 1874 Jan 19 10:23 socktest.pl* $ chmod a-x socktest.pl $ ls -l socktest.pl -rw-r--r-- 1 nick users 1874 Jan 19 10:23 socktest.pl $ chmod g+w socktest.pl $ ls -l socktest.pl -rw-rw-r-- 1 nick users 1874 Jan 19 10:23 socktest.pl $ chmod ug+x socktest.pl $ ls -l socktest.pl -rwxrwxr-- 1 nick users 1874 Jan 19 10:23 socktest.pl* $ chmod ug-wx socktest.pl $ ls -l socktest.pl -r--r--r-- 1 nick users 1874 Jan 19 10:23 socktest.pl