Linux Shell Scripting with Bash

Chapter 4. Script Basics

I was first introduced to computers when my high school purchased a shiny new TRS-80, Model I. The computer was installed in the library, free for anybody to use. I remember following the dog-eared manual and typing in my first BASIC program.

10 PRINT "KEN WAS HERE";
20 GOTO 10

When I ran the program, I was in for a surprise. Not only did the computer faithfully carry out my instructions over and over, but also the words scrolling up the screen formed a shifting pattern. When the screen became full, it scrolled to make room for more messages. If I changed the length of the message to a number that evenly divided into 64 (the TRS-80 had 64 character lines), the messages marched up the screen in neat columns. There was unexpected ...