What is System Call

System Call – It is the interface between the userspace program and kernel program to requests for resources.

Now why we need system calls-

  • Reading and writing from files demand system calls.
  • If a file system wants to create or delete files, system calls are required.
  • System calls are used for the creation and management of new processes.
  • Network connections need system calls for sending and receiving packets.
  • Access to hardware devices like scanner, printer, need a system call.

Here are the five types of System Calls in OS:

  • Process Control – This system call deals with process creation and termination, wait & signal events and allocate and free memory.
  • File Management – This deals with the file manipulation like create, update, delete, read, write and add attributes to the file.
  • Device Management – This deals with the device buffers like reading and writing as well as adding and removing logical devices.
  • Information Maintenance – It handle the data transfer between user and OS kernel.
  • Communications – This is used for inter process communication. Create and delete communication connections, send and receive messages etc.