UNIX in a Nutshell

Here are the changes from the 5/97 reprint:

(xvi): deleted line with "uunet!" address
{11-9}: "if" entry: added parens around "$1 ~ /[Aa].*/"

{18-11}: "merge" entry, "-L text3" option: changed "file1" to
"file3" and 1st "text1" to "text3"