Re: When was stdbuf introduced?

[Pádraig Brady]

On 04/25/2013 07:08 PM, Peng Yu wrote:
> Hi,
> 
> I see stdbuf available in coreutils.
> 
> http://www.gnu.org/software/coreutils/manual/html_node/stdbuf-invocation.html
> 
> But I don't find it in my system. Was stdbuf just introduced recently?
> Or there is something wrong with my installation?
> 
> ~$ wc --version
> wc (GNU coreutils) 8.21
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
> 
> Written by Paul Rubin and David MacKenzie.
> ~$ which stdbuf 2> /dev/null || echo $?
> 1
> ~$ uname -o
> Darwin

So there are various ways to support shared libs on systems,
and I wanted to keep the build as simple as possible.
stdbuf uses LD_PRELOAD to load a shared lib to adjust
the buffering for the specified program, so we'd need
to have access to a darwin system for example to test
that this or an equivalent mechanism works.

Specific support that's checked for at build time is;
In configure.ac we check that it's an ELF system with GCC.
Also in src/local.mk we add the -fPIC -shared flags to GCC.
Note I think newer GCC on Mac OS X support the -shared option,
while older versions required some other flag.

thanks,
Pádraig.