Should be done by an extension or maintenance script, IMO.

ayg wrote:

Regex would mean you would need a table scan to find the correct pages. Not acceptable for Wikimedia projects for arbitrary users (Special:Export/.* on enwiki anyone?). The number of pages that could potentially be returned might also be worrying, and remember that if it takes too long, PHP will time out and nothing will happen. So I don't think this should be enabled by default, either, for the same reasons. Whether it's allowed as a shell script, an extension, or an optional feature I dunno. I predict it will be allowed as whatever the first person to write it decides to write it as.

robchur wrote:

To back up an entire wiki, use the maintenance/dumpBackup.php maintenance script, it's more convenient. I don't think this is an unreasonable option for inclusion in core code, although I would suggest it's switched off when miser mode is on, for obvious reasons. Overall, a more flexible specification of items to be exported might be nice.

Mass compoment change: <some> -> Export/Import

See also Bug 22881 - Greatly improved Export and Import for 1.14.1 (with support for advanced page selection, exporting and importing file uploads, and detection of "conflicts" during import). There's a patch written by me which is related to or fixes your issue.