bash - Add numbers to the beginning of every line in a file

Question

How can I add numbers to the beginning of every line in a file?

E.g.:

This is
the text
from the file.

Becomes:

000000001 This is
000000002 the text
000000003 from the file.

Answer 1

Don't use cat or any other tool which is not designed to do that. Use the program:

nl - number lines of files

Example:

nl --number-format=rz --number-width=9 foobar

Because nl is made for it ;-)