compsci-missing_semester_2020/_subsections/lesson-02.org

lesson 02 | course overview + the shell

• Links
  • timestamps
• Notes
  • bash
    • spaces are critical with bash
    • quotes

Links

• TOC | Missing Semester
• Playlist: Missing Semester

timestamps

1. control flow functions
2. sequential execution
3. standard input
4. error code
5. logical operators
6. concatenate commands
7. common substitution
8. process substitution
9. comparison operator
10. curly braces
11. python script
12. man command
13. finding files
14. grep
15. fuzzy finder
16. history substring search

Notes

bash

spaces are critical with bash

• this works:

foo=bar
echo $foo

• this doesn't:

foo = bar
echo $foo

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

  echo "Hello"

  echo 'Hello'

• double quotes can interpolate variables

  echo "Value is $foo"

  will return: Value is bar

• single quotes can NOT interpoloate variables

  echo 'Value is $foo'

  will return: Value is $foo