owner: In Linux, a file has an owner. By default, a file is owned by the user that creates it, in other words, the user that invokes the application that creates it. Some exceptions and clarifications (or things to be clarified):

• If a script invokes an executable that creates a file, is the created file owned by the owner of the script or by the user who invoked the script? (I need to test sometime -- I don't even have a good guess at this point.)
• If the suid bit is set on an executable that creates a file, the new file is owned by the owner of the executable, not the user who invoked the executable.
• I'm assuming (but need to confirm) that the sgid? bit works similarly -- a file newly created by an executable with the sgid bit set "inherits" the group of the executable.

The owner of a file can use chmod to change the permissions for the owner, group, and world. Only root can change ownership of a file (using chown or chgrp). (Confirm: An executable or script that is suid root (i.e., the suid bit is set and the owner is root) can do things like chown or chgrp.)

See:

• chown
• suid
• sudo
• sticky bit?
• su
• owner
• FileOwnershipAndPermissionsInLinux

Contributors

• RandyKramer - 30 Jan 2002
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