So far, in this book we have been able to see that the echo command is very useful and is going to be in many of our scripts, if not all. We have also seen that this is both a built-in command as well as a command file. When running the echo command, the built-in command will be used unless we state the full path to the file. We can test this with the following command:

$ test -a echo

To gain help on the built-in command, we can use man bash and search for echo; however, the echo command is identical to the internal command so I will recommend that you use man echo in most cases in order to display command options.

The basic use of echo that we have seen so far will produce a text output and a new line. This is often the desired response so we don't have to be concerned that the next prompt will append to the end of the echoed text. The new line separates the script output from the next shell prompt. If we do not supply any text string to print, echo will print only...