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Be careful with long lines – sometimes nano will split long lines into more than one line, which can cause problems in our commands files, as you will see. |
Stringing commands together and controlling their output
In a linux shell, it is often useful to take output of one command save it to a new file rather than having it print to the screen. It uses a familiar metaphor: "pipes". The linux operating system expects some "standard input pipe" and gives output back through a "standard output pipe". These are called "stdin" and "stdout" in linux. There's also a special "stderr" for errors; we'll ignore that for now. Usually, your shell is filling the operating system's stdin with stuff you type - the commands with options. The shell passes responses back from those commands to stdout, which the shell usually dumps to your screen. The ability to switch stdin and stdout around is one of the key reasons linux has existed for decades and beat out many other operating systems. Let's start making use of this. Change to the scratch directory and make a new folder called "piping" and put list of the full contents of the $BI folder to a new file called whatsHere.
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