AC_MSG_RESULT("netlib will use \'$withval\'")
fi
,dnl
-[if test "`(uname) 2>/dev/null`" != IRIX ; then
- AC_CHECK_LIB(socket,main)
-fi
-AC_CHECK_LIB(nsl,main)]
+[AC_LIBRARY_NET]
)])dnl
dnl
dnl HAS_ANSI_VOLATILE
RUN_ENV='LIBPATH=`echo $(PROG_LIBPATH) | sed -e "s/-L//g" -e "s/ /:/g"`:$(PROG_RPATH):/usr/lib:/usr/local/lib; export LIBPATH; '
esac])
+dnl
+dnl The following was written by jhawk@mit.edu
+dnl
+dnl AC_LIBRARY_NET: Id: net.m4,v 1.4 1997/10/25 20:49:53 jhawk Exp
+dnl
+dnl This test is for network applications that need socket() and
+dnl gethostbyname() -ish functions. Under Solaris, those applications need to
+dnl link with "-lsocket -lnsl". Under IRIX, they should *not* link with
+dnl "-lsocket" because libsocket.a breaks a number of things (for instance:
+dnl gethostbyname() under IRIX 5.2, and snoop sockets under most versions of
+dnl IRIX).
+dnl
+dnl Unfortunately, many application developers are not aware of this, and
+dnl mistakenly write tests that cause -lsocket to be used under IRIX. It is
+dnl also easy to write tests that cause -lnsl to be used under operating
+dnl systems where neither are necessary (or useful), such as SunOS 4.1.4, which
+dnl uses -lnsl for TLI.
+dnl
+dnl This test exists so that every application developer does not test this in
+dnl a different, and subtly broken fashion.
+dnl
+dnl It has been argued that this test should be broken up into two seperate
+dnl tests, one for the resolver libraries, and one for the libraries necessary
+dnl for using Sockets API. Unfortunately, the two are carefully intertwined and
+dnl allowing the autoconf user to use them independantly potentially results in
+dnl unfortunate ordering dependancies -- as such, such component macros would
+dnl have to carefully use indirection and be aware if the other components were
+dnl executed. Since other autoconf macros do not go to this trouble, and almost
+dnl no applications use sockets without the resolver, this complexity has not
+dnl been implemented.
+dnl
+dnl The check for libresolv is in case you are attempting to link statically
+dnl and happen to have a libresolv.a lying around (and no libnsl.a).
+dnl
+AC_DEFUN(AC_LIBRARY_NET, [
+ # Most operating systems have gethostbyname() in the default searched
+ # libraries (i.e. libc):
+ AC_CHECK_FUNC(gethostbyname, ,
+ # Some OSes (eg. Solaris) place it in libnsl:
+ AC_CHECK_LIB(nsl, gethostbyname, ,
+ # Some strange OSes (SINIX) have it in libsocket:
+ AC_CHECK_LIB(socket, gethostbyname, ,
+ # Unfortunately libsocket sometimes depends on libnsl.
+ # AC_CHECK_LIB's API is essentially broken so the following
+ # ugliness is necessary:
+ AC_CHECK_LIB(socket, gethostbyname,
+ LIBS="-lsocket -lnsl $LIBS",
+ AC_CHECK_LIB(resolv, gethostbyname),
+ -lnsl)
+ )
+ )
+ )
+ AC_CHECK_FUNC(socket, , AC_CHECK_LIB(socket, socket, ,
+ AC_CHECK_LIB(socket, socket, LIBS="-lsocket -lnsl $LIBS", , -lnsl)))
+ ])