Before we have talked about processes and now you know how to use such utilities as top and top.
And you know that when you enter any command along with possible options and arguments, separate process
is created and there are short running processes like mkdir or long running processes like Bash or FF.
Now it's finally time to explain you what are data streams of every process.
And actually when process is running there are three different data streams called stdin stdout and
stderr.
Those are short names.
Long names are standard in standard out and standard error standard in is inbound data stream.
It comes into the process.
Standard out and standard error are outbound data streams and please note that stdout and stderr are
two different separated data streams.
What it tells us.
It tells us that you are able to redirect different streams to different other processes.
And let me show you how by default, it actually behaves.
Let me go to terminal and here type LS command.
And please note that LHS starts LHS process and here we don't use any arguments and don't use any options.
Simply LHS press enter.
And here I see result.
And this result was produced by stdout data stream.
This text was produced by process and streamed via stdout data stream.
Let me now enter mkdir command and press enter.
And now I see actually error.
This error was streamed via std error from mkdir process.
But how we actually understand that here is error and here is data stream from stdout.
Let me show you it in the next lecture.
Now you need to keep in mind that there are three different data streams in every process.
stdIn stdout and stderr error.
I'll see you in the next lecture.