Interactive login shells, read-eval-print loop (REPL), the Bourne shell implementations ash and dash, including commands: cd, fg, exit, jobs

Introduction

Introduction

ctrl z to sleep

jobs

"jobs" command to see sleeping jobs. can wake up with fg

fg

wakes up sleeping things. (short for foreground)

Introduction

shebang at top.

Pipes

|

Multiple jobs

multiple commands (&), trailing &,

Control flow

&&
||

control flow in sh (do while, case, for loop).

Writing to files

write to file with > (overwrite) and >> (append),
direct stderr to stdout with 2>&1. 

raise error?

Getting interactive input

getting input from user as part of script. doing so in password way to hide input.

Variables

defining variables.

env.

Functions

functions.

Passing variables to shell scripts

passing variables to sh script (-, –?)

xargs

Stream and batch data

stream vs batch data here or elsewhere?

Other commmands

exit. sleep? timer?