perl -e '
open X, "</etc/passwd";
print "$$: $_";
print "$$: all done\n"
I was expecting to see every line printed twice (once by each process, as they don't share a file pointer), or at a push, every line printed once-ish, (if they do).
I definitely wasn't expecting one process not to print anything:
8489: all done
8488: <rest of the file>
8488: all done
Can someone explain what is going on please? At the start of the while loop I would expect the two processes to be identical, bar the return value of fork...
$ perl -v
This is perl 5, version 14, subversion 2 (v5.14.2) built for x86_64-li
(with 89 registered patches, see perl -V for more detail)