As we saw in the previous pages, redirection is one of the last operations undertaken by Bash to parse and prepare the command line that will lead to the execution of a command. But what is a redirection? You can easily guess from your everyday experience. It means taking a stream that goes from one point to another and making it go somewhere else, like changing the flow of a river and making it go somewhere else. In Linux and Unix, it is quite the same, just keep in mind the following two principles:
- In Unix, each process, except for daemons, is supposed to be connected to a standard input, standard output, and standard error device
- Every device in Unix is represented by a file
You can also think of these devices as streams: ...