autoconf support. Moved here from subdirectoy.
diff --git a/extras/iconv.m4 b/extras/iconv.m4
new file mode 100644
index 0000000..7320bef
--- /dev/null
+++ b/extras/iconv.m4
@@ -0,0 +1,39 @@
+#serial 1
+
+dnl From Bruno Haible.
+
+AC_DEFUN(jm_ICONV,
+[
+ dnl Some systems have iconv in libc, some have it in libiconv (OSF/1 and
+ dnl those with the standalone portable libiconv installed).
+ AC_CACHE_CHECK(for iconv, jm_cv_func_iconv, [
+ jm_cv_func_iconv="no, consider installing libiconv"
+ jm_cv_lib_iconv=no
+ AC_TRY_LINK([#include <stdlib.h>
+#include <iconv.h>],
+ [iconv_t cd = iconv_open("","");
+ iconv(cd,NULL,NULL,NULL,NULL);
+ iconv_close(cd);],
+ jm_cv_func_iconv=yes)
+ if test "$jm_cv_func_iconv" != yes; then
+ jm_save_LIBS="$LIBS"
+ LIBS="$LIBS -liconv"
+ AC_TRY_LINK([#include <stdlib.h>
+#include <iconv.h>],
+ [iconv_t cd = iconv_open("","");
+ iconv(cd,NULL,NULL,NULL,NULL);
+ iconv_close(cd);],
+ jm_cv_lib_iconv=yes
+ jm_cv_func_iconv=yes)
+ LIBS="$jm_save_LIBS"
+ fi
+ ])
+ if test "$jm_cv_func_iconv" = yes; then
+ AC_DEFINE(HAVE_ICONV, 1, [Define if you have the iconv() function.])
+ fi
+ LIBICONV=
+ if test "$jm_cv_lib_iconv" = yes; then
+ LIBICONV="-liconv"
+ fi
+ AC_SUBST(LIBICONV)
+])
