(@dir0) = readdir(ID) || print "Couldn't read directory contents.\n";

##</code><code>##

@dir0 = (readdir(ID) || 1); # assuming print doesn't fail

##</code><code>##

(@dir0 = readdir(ID)) || print "...";

##</code><code>##

@dir0 = readdir(ID) or print "...";

##</code><code>##

2;0 juerd@ouranos:~$ perl -MO=Deparse,-p -e'(@dir) = readdir(ID) || print "X"'
(@dir = (readdir(ID) || print('X')));
-e syntax OK