File permissions and ownership are one of the distinguishing features of the Unix/Linux filesystems. These features protect your information in a multi-user environment. Mismatched permissions and ownership can also make it difficult to share files. These recipes explain how to use a file's permission and ownership effectively.
Each file possesses many types of permissions. Three sets of permissions (user, group, and others) are commonly manipulated.
The user is the owner of the file, who commonly has all access permitted. The group is the collection of users (as defined by the system administrator) that may be permitted some access to the file. Others are any users other than the owner or members of the owner's group.
The ls command's -l option displays many aspects of the file including type, permissions, owner, and group:
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