#+title: lesson 02 | course overview + the shell
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../_share/media/css/missing-semester.css" />
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../_share/media/css/org-media-sass/collapsible.css" />
#+HTML_HEAD: <script src="../_share/media/js/collapsible.js"></script>

* Links
#+attr_html: :class links
- [[../toc.org][TOC | Missing Semester]]
- [[https://www.youtube.com/playlist?list=PLyzOVJj3bHQuloKGG59rS43e29ro7I57J][Playlist: Missing Semester]]

*** timestamps
:PROPERTIES:
:CUSTOM_ID: timestamp
:END:

#+attr_html: :class playlist
1. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=54s][control flow functions]]
2. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=227s][sequential execution]]
3. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=425s][standard input]]
4. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=444s][error code]]
5. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=517s][logical operators]]
6. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=603s][concatenate commands]]
7. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=645s][common substitution]]
8. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=675s][process substitution]]
9. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=935s][comparison operator]]
10. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=1173s][curly braces]]
11. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=1359s][python script]]
12. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=1707s][man command]]
13. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=2175s][finding files]]
14. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=2190s][grep]]
15. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=2573s][fuzzy finder]]
16. [[https://www.youtube.com/watch?v=kgII-YWo3Zw&t=2649s][history substring search]]

* Notes

** bash
*** spaces are critical with bash
  - this works:
  #+begin_src bash
  foo=bar
  echo $foo
  #+end_src

  - this doesn't:

  #+begin_src bash
  foo = bar
  echo $foo
  #+end_src

  the output of that will be
  =zsh: command not found: foo=

  - what happens in the above example is that we are effectively calling the "foo" program with the arguments: "=" and "bar"

*** quotes
- you can use double or single quotes to print a value
    #+begin_src bash
    echo "Hello"
    #+end_src
    #+begin_src bash
    echo 'Hello'
    #+end_src

- double quotes can interpolate variables
  #+begin_src bash
  echo "Value is $foo"
  #+end_src

  will return: =Value is bar=

- single quotes can NOT interpoloate variables
  #+begin_src bash
  echo 'Value is $foo'
  #+end_src

  will return: =Value is $foo=