what is the effect of the sticky bit when set on a directory
Sticky bit 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 other users' files.
Static variable In general, static memory allocation is the allocation of memory at compile time, before the associated program is executed, unlike dynamic memory allocation or automatic memory allocation where memory is allocated as required at run time.[1]