File permissions for Unix files can be managed from the
A Unix file or folder has a single individual owner plus a
single group owner.
Current permissions of the individual owner are displayed and
can be modified by
- Adding checked permissions to current set
- Removing checked permissions from the current set
- Replacing the current set with a new set
Permissions for Unix file system files can be managed at https://ubfs.buffalo.edu/.
Groups are uniquely named entities for a particular system that
can be used to specify file permissions. For example, at UB, there
are institutional and AD groups.
Every user may be a member of one or more “groups”,
including a “primary group”. Every file belongs to only
one user and to only one group.
When a file is created in Unix, its owner is the person who
created it. The default group is the primary group of the owner or
the group of the directory in which it was created. Changing the
group owner of a directory causes all files subsequently created in
that directory to be created with the new group.
in to ubunix.buffalo.edu:
- Type groups to see groups to which you belong.
- Type grep group_name /etc/group to display the
membership of a particular group.
Checking Apply Recursively causes a change (add, replace or
remove) made to any folder to be made to all existing and future
files or subfolders in that folder. To change permissions that have
been inherited for a specific file or folder, use the replace or
remove option to change the undesired permissions and then set the
permissions on the target folder or file.
setuid (set user ID) and setgid (set group ID) are
flags in Unix file systems that:
- allow users to execute a file temporarily using the permissions
of the file’s owner (individual or group)
- are represented symbolically by an s as in drwxrwxrws or
Using setgid on a directory causes new files and subdirectories
to inherit the specified group or the setgid bit
Using setgid on a directory does not affect existing
files and subdirectories.
Sticky bit is a flag for directories in Unix file systems
- disallows renaming or renaming files in the directory by anyone
other than the file or directory owner or a superuser
- is represented symbolically by a t in the final
character-place, as in drwxrwxrwxt or drwxrwxrwT