O_TRUNC Truncate the file
O_NONBLOCK Non-blocking access
-Less common flags that are sometimes available on some operating systems
-include C<O_BINARY>, C<O_TEXT>, C<O_SHLOCK>, C<O_EXLOCK>, C<O_DEFER>,
-C<O_SYNC>, C<O_ASYNC>, C<O_DSYNC>, C<O_RSYNC>, C<O_NOCTTY>, C<O_NDELAY>
-and C<O_LARGEFILE>. Consult your open(2) manpage or its local equivalent
-for details.
+Less common flags that are sometimes available on some operating
+systems include C<O_BINARY>, C<O_TEXT>, C<O_SHLOCK>, C<O_EXLOCK>,
+C<O_DEFER>, C<O_SYNC>, C<O_ASYNC>, C<O_DSYNC>, C<O_RSYNC>,
+C<O_NOCTTY>, C<O_NDELAY> and C<O_LARGEFILE>. Consult your open(2)
+manpage or its local equivalent for details. (Note: starting from
+Perl release 5.6 the O_LARGEFILE flag, if available, is automatically
+added to the sysopen() flags because large files are the the default.)
Here's how to use C<sysopen> to emulate the simple C<open> calls we had
before. We'll omit the C<|| die $!> checks for clarity, but make sure