+=item $errnum = $h->last_errno ();
+
+This returns the last error number (errno) that happened on the
+handle C<$h>.
+
+If successful, an errno integer not equal to zero is returned.
+
+If no error number is available, this returns 0.
+See L<guestfs(3)/guestfs_last_errno> for more details of why
+this can happen.
+
+You can use the standard Perl module L<Errno(3)> to compare
+the numeric error returned from this call with symbolic
+errnos:
+
+ $h->mkdir (\"/foo\");
+ if ($h->last_errno() == Errno::EEXIST()) {
+ # mkdir failed because the directory exists already.
+ }
+