Introduction
We’re here to teach you about computers and computers really do four things:
- run programs
- store data
- communicate with each other
- and interact with us
They can do the last of these in many different ways. The most common way of doing this is using a graphical interface. Another way to do this is using a command line text interface called the shell.
The shell is very useful for three main reasons:
- Automating data analysis
- Combining existing tools in powerful ways with only a few keystrokes
- Interacting with remote machines
###Why you should care
- Demo a workflow pipeline (use old Adv HW3)
- Need to understand all of this to do equivalent things in other languages
Shortcuts
- Up and down arrows
- Tab
- history
Wednesday
Shebangs
A shebang is a special code at the beginning of a script to tell the shell to run it as a scripot for a particular language.
Comes from Sharp(#) + Bang(!)
Syntax
#!/path/to/interpreter#!/bin/bash#!/usr/bin/python
Portability
Above commands work on Linux and Mac. To allow use on Windows:
#!/usr/bin/env bash#!/usr/bin/env python
This looks for the interpreter in the PATH