Outline:

1. File descriptors
   • basics
   • redirection
   • examples: files.c and redirect.c
2. Processes
   • Unix process model abstraction
   • syscalls, context switches, and scheduling
   • a note on terminology
   • fork, wait, and exit
   • example: forktest.c

Explore after class:

3. Lab 8: Getting started with processes
4. Shell-related example code
   • using exec: exectest.c
   • a really simple shell: shell208.c
   • stdin/stdout redirection: redirect.c
   • working with pipes: pipe.c
   • working with signals: signaltest.c

Want more practice with fork?

5. DiS exercises

Reading assignment (to be completed by the next class):

• Assignment 9 – think of it as putting together a puzzle to build your shell :)
• File systems and redirection:
  • DiS Sec. 17.1: Unix Command Line and the Unix File System
  • DiS Sec. 17.12: I/O Redirection
• Processes and inter-process communication:
  • DiS Sec. 13.2: Processes
  • DiS Sec. 13.4.2: Message Passing
  • DiS Sec. 17.13: Pipes

Additional exploration:

• Manual pages (e.g., type man <cmd>, replacing <cmd>, in a terminal) for:
  • fork
  • wait
  • execlp
  • execvp
  • signal