shell-command-on-region (M-|) does not do the {de,en}coding of I/O to the process as documented.<div><br></div><div>It says (if I read it correctly) that it will use buffer-file-coding-system (at least unless coding-system-for-{read,write} are set) for output to and input from (if doing substitution with a prefix argument) the process.</div>
<div><br></div><div>However, it &quot;just&quot; calls call-process-region which will use default-process-coding-system rather than buffer-file-coding-system.</div><div><br></div><div>To try, &#39;emacs -q&#39;, switch to an empty buffer, and:</div>
<div><br></div><div>  C-x RET f iso-8859-7 RET C-SPC C-u M-| echo -e &#39;\0245&#39; RET</div><div><br></div><div>This does not insert a drachma sign.</div><div><br></div><div>However, if you run (setq default-process-coding-system &#39;(iso-8859-7 iso-8859-7)) first, it does indeed produce a drachma.</div>
<div><br></div><div>Output encoding works the same way.</div><div><br></div><div>- Gustav</div><div><br></div>