|(operating system)||sticky bit - The bit in the mode of a Unix file
which, if set for an executable, tells the kernel to keep
the code loaded in swap space even after it has finished
executing on the assumption that it is likely to be used again
soon. This performance optimisation was included in some
early (and recent?) versions of Unix to save reloading
frequently used programs such as the shell or vi from
If the sticky bit is set on a directory, an unprivileged user may not delete or rename files of other users in that directory even if he has write access to the directory.
The Unix "ls" command displays a set sticky bit as a "t" in the permissions of a file or directory.