7.1.1. Here Documents

The << label redirector essentially forces the input to a command to be the shell's standard input, which is read until there is a line that contains only label. The input in between is called a here-document. Here-documents aren't very interesting when used from the command prompt. In fact, it's the same as the normal use of standard input except for the label. We could use a here-document to simulate the mail facility. When you send a message to someone with the mail utility, you end the message with a dot (.). The body of the message is saved in a file, msgfile:

$ cat >> msgfile << .
  > this is the text of
  > our message.
  > .

Here-documents are meant to be used from within shell scripts; they let you specify "batch" input to programs. A common use of here-documents is with simple text editors like ed.

Wow, this is HTML or something