This session will deal with various file related system calls. It starts with repositioning the current file offset using lseek(). Creating soft link to a file, changing permissions, and ownership of a file from within a C program. Different techniques of I/O redirection are discussed using dup() and dup2() system calls. Finally, the use of fcntl() system call is discussed to duplicate a file descriptor, get/set file descriptor flags in PPFDT, get/set file status flags in SWFT, and achieving advisory locks on files