How can I copy the output of a command directly into my clipboard?

How can I pipe the output of a command into my clipboard and paste it back when using a terminal? For instance:

cat file | clipboard

One way of doing it follows:

1. Install xclip, such as:

   sudo apt-get install xclip

2. Pipe the output into xclip to be copied into the clipboard:

   cat file | xclip

3. Paste the text you just copied into a X application:

   xclip -o

To paste somewhere else other than an X application, such as a text area of a web page in a browser window, use:

cat file | xclip -selection clipboard

Consider creating an alias:

alias "c=xclip"
alias "v=xclip -o"

To see how useful this is, imagine I want to open my current path in a new terminal window (there may be other ways of doing it like Ctrl+T on some systems, but this is just for illustration purposes):

Terminal 1:
pwd | c

Terminal 2:
cd `v`

Notice the ` ` around v. This executes v as a command first and then substitutes it in-place for cd to use.

Only copy the content to the X clipboard

cat file | xclip