May 11, 2021

Software Development Life Cycle (SDLC) is the application of standard business practices to building software applications. It’s typically divided into six to eight steps: Planning, Requirements, Design, Build, Document, Test, Deploy, Maintain. Six Phases of the System Development Life Cycle Preliminary Investigation Assesses feasibility and practicality of system System Analysis Study old system and identify

System calls sequence to copy the contents of one file to another file Programming interface to the services provided by the OS Typically written in a high level language (C or C++) Mostly accessed by programs via a high level Application Program Interface (API) rather than direct system call use Three most common APIs are

These are the pieces of the operating system components we’ll be looking at: Process Management Main Memory Management File Management I/O System Management Secondary Management Networking Protection System Command-Interpreter System Process Management A process is a program in execution: (A program is passive, a process active.) A process has resources (CPU time, files) and attributes