Operating System Prof.P.M.Sawant
Operating system Concepts • Process- Program in execution • File-Long term storage • System call-interface to the services • The command interpreter-provides command line interface • Signals-to notify a process that a particular event has occurred
System call • System call provides an interface to the operating system services • System calls are how user space programs interact with the kernel. • Each and every system call has a system call number which is known by both the user space and the kernel. • For example, both know that system call number 10 is open(), system call number 11 is read(), etc.
Standard C Library Example • C program invoking printf() library call, which calls write() system call 3/7/2019 4