Re: bin/59453 (sed 's/^/\x23def/' output '=ef' instead of '#def')

["Martin Husemann via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR bin/59453; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/59453 (sed 's/^/\x23def/' output '=ef' instead of '#def')
Date: Mon, 2 Jun 2025 12:12:16 +0200

 This seems to be not documented anywhere. The gnu sed documentation does
 not specify it clearly, but gnu sed takes one or two hex characters after
 \x.
 
  > echo | gsed 's/^/\x1023def/' | hexdump -C
 00000000  10 32 33 64 65 66 0a                              |.23def.|
  > echo | gsed 's/^/\x1t023def/' | hexdump -C
 00000000  01 74 30 32 33 64 65 66  0a                       |.t023def.|
 
 We should document it as GNU sed compatible extension (maybe borrowing
 the portability warning from sh(1)).
 
 Martin