Shot yourself in the foot with carriage return.

Just today somebody had a problem with a file that he "could not cat",
but less worked. The reason was that the file had only a carriage
return at the end of the only line.

Here's an example how to reproduce:

> echo -en "bla\r" > bla2
> cat bla2
> od -c bla2
0000000 b l a \r
0000004