How to write buffer content to stdout?

Question

Is there any chance to write the content of the current vim buffer to stdout?

I\'d like to use vim to edit content that was passed via stdin - without the need of a

Answer 1

vim can be used in pipes as full-featured filter with explicit names for stdin and stdout as in following example:

echo xxx                                             |
vim                                                  \
  -esnN -i NONE                                      \
   +'1 s /x/y/g | 1 s /^/Hallo / | x! /dev/stdout'   \
   /dev/stdin                                        |
cat -n

Abbreviating /dev/stdin with - won't work, even not with -v flag.