Lucid Programming Dojo : 201 : Introduction to the Shell

• 301 Ruby Course (This Dojo 201 course leads up the Dojo 301 Ruby course)
• Dojo Course Flyer
• UNIX File System
• Apple Introduction to Shell Scripting
• Advanced BASH

While we enjoy delicious Italian food the Lucid Programming Dojo : 201 Introduction to the shell course aims to cover the following topics :

• Drinking a Beverage
• Key Course Points
• What is a shell? (Wikipedia : Computing Shell, UNIX Shell)
  • Atari - runs Basic
  • LISP machine - runs LISP
  • Fundamentally a Read-Evaluate-Print Loop REPL with specific syntax and semantics.
• Why use a shell?
  • To perform a task, to retrieve some kind of information.
  • To interact with the Operating System - sometimes the only way.
  • Automatic tasks and procedures reliably.
• UNIX Based Shells
  • ZSH
  • BASH
  • SH
  • TCSH
• Windows Shells
  • Windows Power Shell - not covered in this course
  • DOS - not covered in this course
• UNIX philosophy
  1. Write small programs that do one thing and do it well.
     • Isolates functionality into useful building blocks.
  2. Write programs to work together.
     • Compose a workflow from individual pieces easily.
  3. Write programs to handle text streams, because that is a universal interface.
     • Input and Output
     • The file system
       • Data with associated meta-data including name, permissions, type, etc.
       • Arranged in a way to create meaningful structure, e.g. directories and sub-directories.
     • Everything is a file
       • Well, nearly everything. Depends on platform and implementation.
       • e.g. on Linux processes show up in /proc, but this is not the case on Mac OS X.
     • Programs
       • Programs do one thing well
       • Programs accept textual input (stdin)
       • Programs provide textual output (stdout, stderr)
       • Using multiple programs to complete a task
         • Moving data between programs with files
         • Moving data between programs with pipes
  4. Man pages and -h/–help
     • Google
     • Bash Snippets
     • Die LINUX man pages
     • Code Snippets examples
• Introduction to BASH
  • The command line
  • Executing commands
  • What are arguments
  • Looking at files in the file system (ls, LS Examples)
  • Moving around the file system (cd)
  • Current Working Directory (pwd)
  • Interacting with files in the file system
  • Editing files in the file system
    • Introduction to command line text editor programs
      • nano
      • vim
    • TextMate
  • Basic BASH script
  • Job Control (^Z, jobs, fg, bg)
  • Processes (top, ps)
• Having some Lunch
• Basic usage of the following command line tools :
  • awk (AWK by example)
  • grep
  • sed
  • find
  • xargs
• Regular Expressions
• Shell Scripting
  • What is a shell script
  • How to make a shell script
  • Flow control within a script
    • Loops
    • Conditionals
  • Now you can create a shell script what will this allow you to do?
• Enjoying Desert

• AWK and Loops
• Disk usage summary of a user on a system
• Processing Arguments