On Mon, May 28, 2012 at 4:38 PM, Magnus Hagander <mag...@hagander.net> wrote: > On Mon, May 28, 2012 at 10:11 PM, Peter Eisentraut <pete...@gmx.net> wrote: >> In 9.1, the pg_basebackup option --xlog takes no argument. In 9.2, it >> takes a required argument. I think such compatibility breaks should be >> avoided, especially in client-side programs. Now you can't write a >> script running pg_basebackup that works with 9.1 and 9.2, if you need to >> include the WAL. >> >> I think the behavior of -x/--xlog should be restored to the state of >> 9.1, and a new option should be added to select between the fetch and >> stream methods. (With a suitable default, this would also increase >> usability a bit.) > > Just to be clear - it's not possible to actually accept -x with an > *optional* parameter, is it? Meaning "-x" would mean the same as "-x > fetch" and therefor become backwards compatible? > > IIRC I did try that, and didn't get it to work - but if that's doable, > that seems like the cleanest way?
Aren't you still going to have situations where it's the behavior changes, if you go this route? Consider this command line: $ foo -b bar Is bar an argument to -b, or an argument to foo? If -b required or forbade an argument it would be clear, but if the argument is optional then it's fuzzy. Similarly, consider: $ foo -bar If -b takes no argument then this means the same thing as "foo -b -a -r", but and if -b requires an argument then ar is the argument to foo. If -b takes an optional argument, then it's ambiguous. I don't remember the exact behavior of getopt_long(), but I bet if we go this route we'll find that there are cases where the behavior changes vs. older releases; they'll just be subtler. Peter's suggestion of a separate switch seems better to me for that reason. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers