{"id":2513,"date":"2010-10-19T06:16:53","date_gmt":"2010-10-18T20:16:53","guid":{"rendered":"http:\/\/nsrd.info\/blog\/?p=2513"},"modified":"2018-12-11T18:30:26","modified_gmt":"2018-12-11T08:30:26","slug":"mminfo-and-not-queries","status":"publish","type":"post","link":"https:\/\/nsrd.info\/blog\/2010\/10\/19\/mminfo-and-not-queries\/","title":{"rendered":"mminfo and NOT queries"},"content":{"rendered":"

A question that’s just come up on the NetWorker mailing list again (it’s a periodic one) is, “how do I query mminfo to return all savesets that don’t belong to a particular group?” or “how do I return all savesets except those belonging to a single client?”<\/p>\n

The part of mminfo here that causes the confusion is the bang operator \u2013 otherwise known as the exclamation mark (!).<\/p>\n

In a lot of programming languages, an exclamation mark is typically equated with “not”. For instance, if we look at Perl:<\/p>\n

if ($a != b)<\/em><\/strong><\/p>\n

Means “If the value of $a is not equal to the value of $b”. It’s a similar story in other languages that make use of the exclamation mark. Indeed, making it perhaps a little more confusion to the uninitiated is that in mminfo, ! does indeed mean “not”; the trick though is that it’s not available for all possible usages, just a subset.<\/p>\n

In particular, you can only use the exclamation mark within an mminfo query when against a flag<\/em> field. Not a string field, nor a numeric field, etc. Just a flag field. The “catch” is that if you use it against a non-flag field, mminfo won’t abort the query, but will instead ignore the not <\/em>component specified. This means that if you specify, say:<\/p>\n

# mminfo -q \"!client=archon,savetime>=24 hours ago\"<\/strong><\/pre>\n
The query actually executed will be:<\/p>\n
# mminfo -q \"client=archon,savetime>=24 hours ago\"<\/strong><\/pre>\n
There’s clearly a big difference between the two, and it’s brought a few people unstuck.<\/p>\n
As it currently stands in NetWorker, if you want to retrieve mminfo details for strings that don’t<\/em> match particular patterns, your only option is to use an external filter, such as:<\/p>\n
    \n
  • A command line utility, such as grep;<\/li>\n
  • Writing the output to a text file and manually extracting;<\/li>\n
  • Writing a custom filter programme;<\/li>\n
  • Writing the output to a CSV file and filtering in a spreadsheet.<\/li>\n<\/ul>\n
    It would certainly be highly desirable for NetWorker’s mminfo command to be updated to fully support the not\/’!’ syntax; until then however keep in mind that it will be ignored for non-flag fields, and you’ll avoid getting into trouble with it.<\/p>\n","protected":false},"excerpt":{"rendered":"
    A question that’s just come up on the NetWorker mailing list again (it’s a periodic one) is, “how do I…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[16,20],"tags":[28,594,643],"class_list":["post-2513","post","type-post","status-publish","format-standard","hentry","category-networker","category-scripting","tag-28","tag-mminfo","tag-not"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t