The first line writes "hello world" to the file "output", the second reads it back and writes it to standard output (normally the terminal). A "here" document is essentially a temporary, nameless file ...

In addition to the fairly common forms of input/output redirection the shell recognizes something called process substitution. Although not documented as a form of input/output redirection, its syntax ...

If you have any experience with the Linux command line, you’ve probably used a pipe to solve tasks by combining simple ...