what searches the given files for all occurrences of the identification pattern
@(#) or
$Id: and writes a line
to the standard output containing the text that follows until the first occurrence of one of the following:
" < > \ $
newline NUL. If no
file is given or if a
file is
- then the standard input is read. The name of each input
file, followed by a
:, is also written as a separate line to the standard output.