Can vim execute buffer without addons?

If editing some script in vim, a file with .py or .sh extension, is it any build-in vim command that allows to run such file? I know it's a lot of IDE-like addons for VIM that allows to execute files vim edit, but is it possible without addons?

Solution 1:

I hope I'm not offending you by answering, that to run the current file (not buffer) you just

:!%

UPD: To run buffer to interpreter's standard input (without saving to a file first):

:w !/bin/sh

The latter can be also used with python, with perl -w, etc.

By the way, a super useful technique is to filter a buffer through external command:

1G!Ggrep -v unwanted_regex

All these are vi compatible.