Sticky bit

Common card · No. 481791

In computing, the sticky bit is a user ownership access right flag that can be assigned to files and directories on Unix-like systems. There are two definitions: one for files, and one for directories. For files, particularly executables, the superuser could tag these as to be retained in main memory, even when their need ends, to minimize swapping that would occur when another need arises, and the file now has to be reloaded from relatively slow secondary storage. This function has become obsolete due to swapping optimization. For directories, when a directory's sticky bit is set, the filesystem treats the files in such directories in a special way so only the file's owner, the directory's owner, or root user can rename or delete the file. Without the sticky bit set, any user with write and execute permissions for the directory can rename or delete contained files, regardless of the file's owner. Typically this is set on the /tmp directory to prevent ordinary users from deleting or moving...

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