Re: ssh (fwd)

[Mark Kettenis <kettenis@wins.uva.nl>]

   From: e-guy@skylab.net
   Date: Wed, 27 Oct 1999 20:42:04 +0200 (CEST)

   a question: the _GNU_SOURCE define only for hurd and only for compile the
   other gnu sources?

_GNU_SOURCE is used to indicate that GNU extensions should be made
available to your program.  Most things beyond what Unix98 specifies
for <utmpx.h>, such as WTMP_FILE, are considered GNU extensions.
That's why you have to specify _GNU_SOURCE to compile ssh.

The GNU C Library has several macros that do similar things as
_GNU_SOURCE.  They are called "feature test macros".  There is for
instance _POSIX_SOURCE (makes everthing defined by POSIX.1 available),
_BSD_SOURCE (makes things found on BSD systems available).  A complete
list can be found in the glibc documentation.

Mark