-dnl AC_LBL_LIBRARY_NET
-dnl
-dnl This test is for network applications that need socket() and
-dnl gethostbyaddr() -ish functions. Under Solaris, those applications
-dnl need to link with "-lsocket -lnsl". Under IRIX, they need to link
-dnl with "-lnsl" but should *not* link with "-lsocket" because
-dnl libsocket.a breaks a number of things (for instance:
-dnl gethostbyaddr() under IRIX 5.2, and snoop sockets under most
-dnl versions of IRIX).
-dnl
-dnl Unfortunately, many application developers are not aware of this,
-dnl and mistakenly write tests that cause -lsocket to be used under
-dnl IRIX. It is also easy to write tests that cause -lnsl to be used
-dnl under operating systems where neither are necessary (or useful),
-dnl such as SunOS 4.1.4, which uses -lnsl for TLI.
-dnl
-dnl This test exists so that every application developer does not test
-dnl this in a different, and subtly broken fashion.
-
-dnl It has been argued that this test should be broken up into two
-dnl separate tests, one for the resolver libraries, and one for the
-dnl libraries necessary for using Sockets API. Unfortunately, the two
-dnl are carefully intertwined and allowing the autoconf user to use
-dnl them independently potentially results in unfortunate ordering
-dnl dependencies -- as such, such component macros would have to
-dnl carefully use indirection and be aware if the other components were
-dnl executed. Since other autoconf macros do not go to this trouble,
-dnl and almost no applications use sockets without the resolver, this
-dnl complexity has not been implemented.
-dnl
-dnl The check for libresolv is in case you are attempting to link
-dnl statically and happen to have a libresolv.a lying around (and no
-dnl libnsl.a).