I have a very large UNIX file (>4G) that I need to edit. Every occurance of a tilde (~) not followed by a pipe (|) should be changed to a tilde followed by a space. I am told that SED is a UNIX stream editing program that would be ideal for this kind of edit, and I am told SED is freely available on the web.
First, where can I get an SED download?
Second, what would the replace command line parameter look like to accomplish the task?