lseek.2: O_APPEND overrides the effect of lseek() when doing file writes

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

man2/lseek.2

@@ -237,6 +237,15 @@ See
 for a discussion of the relationship between file descriptors,
 open file descriptions, and files.
 
+If the
+.B O_APPEND
+file status flag is set on the open file description,
+then a
+.BR write (2)
+.I always
+moves the file offset to the end of the file, regardless of the use of
+.BR lseek ().
+
 The
 .I off_t
 data type is a signed integer data type specified by POSIX.1.