#Requirements

We will write a tiny shell (tsh) command processor like sh, bash, or csh for single line commands. Your shell’s main loop will display a prompt, read a line of input, and fork a child process to perform the indicated command.

Required capabilities:

  1. Ordinary commands, consisting of an executable program name and an optional list of arguments, run in a separate process.

  2. Two built-in commands: cd and pwd

  3. Background processing, when the last token in the command line is “&”.

#Implementation

  1. get user input

  2. parse oneline cmd , create command argv &

  3. if cmd is build-in cmd, call corresponding system call

  4. if not, create a child process, and execvp the cmd

    1
    The exec family of functions replaces the current process image with a new process image.

  5. if it is not a background process, use waitpid for childprocess

links to assignment6