On Mon, May 22, 2023, at 5:35 AM, Po Lu wrote: > When did AS_ECHO start to emit calls to `printf' Git commit 2b59b6f8a79b8bf77e178ff4e5aa0ede433d39cf, dated 2013 Jan 28. There was some discussion of the trade-offs involved on the bug-autoconf mailing list four years before that, see https://lists.gnu.org/archive/html/bug-autoconf/2009-07/msg00025.html et seq. > and `AS_UNSET' to `unset'? Commit 26ba5ebd23bcee95d446181b57dac61d7163c041, dated 2008 Oct 14. Note that in this case, what Autoconf does is *find a shell implementation that supports unset* and re-exec itself using that. If it can't find any such shell, it errors out. > printf is not portable; it is missing, both as a built-in to ksh and a > command, on Ultrix 4.5, as well as (AFAIK) Solaris 2.6, the first of > which is important for historical purposes, and the second of which is > still found in the wild in some fields. I would be willing to consider a patch that adds to _AS_DETECT_BETTER_SHELL a check for support for `printf '%s' "$message"` and `printf '%s\n' "$message"` (those two constructs specifically), and/or a patch that partially restores _AS_ECHO_PREPARE such that it attempts to fall back to `echo [-n]` on systems where the above two constructs don't work. If you do not have time to develop such a patch, I regret to say that no one else reading this message is likely to have the time in the near future either. Also, I myself do not have access to either an Ultrix 4.5 or a Solaris 2.6 installation, so I could not test the patch properly and would have to demand a lot of specific testing from you. zw
