Another way to manipulate stdin and stdout is to have one command take its input directly from the output of another command. To do this, Unix uses the , or pipe , character to connect commands together to form pipelines , with the stdout of each command being piped into the stdin of the next one. The stderr is not affected by the pipeline. The use of pipes enables you to create an almost infinite variety of command lines processing input and output to what are nothing more than miniature custom applications.
To pipe the output of one command into another:
Assuming your computer is connected to the Internet, you can pipe the output of any command into an e-mail message for another user on the Internet.
To pipe the output of a command into e-mail: