Something

{ echo "$as_me:$LINENO: checking for library containing iconv_open" >&5
echo $ECHO_N "checking for library containing iconv_open... $ECHO_C" >&6; }
if test "${ac_cv_search_iconv_open+set}" = set; then
  echo $ECHO_N "(cached) $ECHO_C" >&6
else
  ac_func_search_save_LIBS=$LIBS
cat >conftest.$ac_ext <<_ACEOF
/* confdefs.h.  */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
cat >>conftest.$ac_ext <<_ACEOF
/* end confdefs.h.  */

/* Override any GCC internal prototype to avoid an error.
   Use char because int might match the return type of a GCC
   builtin and then its argument prototype would still apply.  */
#ifdef __cplusplus
extern "C"
#endif
char iconv_open ();
int
main ()
{
return iconv_open ();
  ;
  return 0;
}
_ACEOF
for ac_lib in '' iconv; do
  if test -z "$ac_lib"; then
    ac_res="none required"
  else
    ac_res=-l$ac_lib
    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
  fi
  rm -f conftest.$ac_objext conftest$ac_exeext
if { (ac_try="$ac_link"
case "(($ac_try" in
  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
  *) ac_try_echo=$ac_try;;
esac
eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
  (eval "$ac_link") 2>conftest.er1
  ac_status=$?
  grep -v '^ *+' conftest.er1 >conftest.err
  rm -f conftest.er1
  cat conftest.err >&5
  echo "$as_me:$LINENO: \$? = $ac_status" >&5
  (exit $ac_status); } && {
         test -z "$ac_c_werror_flag" ||
         test ! -s conftest.err
       } && test -s conftest$ac_exeext &&
       $as_test_x conftest$ac_exeext; then
  ac_cv_search_iconv_open=$ac_res
else
  echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5


fi

rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
      conftest$ac_exeext
  if test "${ac_cv_search_iconv_open+set}" = set; then
  break
fi
done
if test "${ac_cv_search_iconv_open+set}" = set; then
  :
else
  ac_cv_search_iconv_open=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ echo "$as_me:$LINENO: result: $ac_cv_search_iconv_open" >&5
echo "${ECHO_T}$ac_cv_search_iconv_open" >&6; }
ac_res=$ac_cv_search_iconv_open
if test "$ac_res" != no; then
  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"

cat >>confdefs.h <<\_ACEOF
#define USE_ICONV 1
_ACEOF

fi