adjtimex.2: Add featute test macro requirements

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man2/adjtimex.2 b/man2/adjtimex.2
index c642510b055abe796f4ea8cdfae6368544ca10e8..b5fd2570454fad60a21bb4dbbba19a6635ed3927 100644 (file)
--- a/man2/adjtimex.2
+++ b/man2/adjtimex.2
@@ -38,9 +38,12 @@
 .SH NAME
 adjtimex \- tune kernel clock
 .SH SYNOPSIS
+.nf
+.BR "#define _BSD_SOURCE" "      /* See feature_test_macros(7) */"
 .B #include <sys/timex.h>
-.sp
+
 .BI "int adjtimex(struct timex *" "buf" );
+.fi
 .SH DESCRIPTION
 Linux uses David L. Mills' clock adjustment algorithm (see RFC\ 1305).
 The system call