Re: sed(1) and LC_CTYPE

[Taylor R Campbell <campbell+netbsd-tech-userlevel%mumble.net@localhost>]

> Date: Wed, 26 Jul 2023 17:32:03 +0200
> From: tlaronde%polynum.com@localhost
> 
> If setting LC_CTYPE to this:
> 
> $ export LC_CTYPE=fr_FR.ISO8859-15
> 
> and then:
> 
> $ echo "éé" | sed 's/é/\é/g'
> sed: 1: "s/é/\é/g": RE error: trailing backslash (\)
> 
> Where does the program manage to find a backslash i.e. 0134? While
> 'é' is 0351.

Exactly what bytes are passed as an argument to sed?  Can you write a
program that will hexdump argv[1] and pass the same argument to it?

Next step, if that reveals the expected 0xe9, is to find exactly what
string is passed to regcomp inside sed.