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authorDaniel Baumann <daniel.baumann@progress-linux.org>2018-11-07 12:19:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2018-11-07 12:20:17 +0000
commita64a253794ac64cb40befee54db53bde17dd0d49 (patch)
treec1024acc5f6e508814b944d99f112259bb28b1be /libnetdata/simple_pattern/README.md
parentNew upstream version 1.10.0+dfsg (diff)
downloadnetdata-upstream/1.11.0+dfsg.tar.xz
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New upstream version 1.11.0+dfsgupstream/1.11.0+dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+## netdata simple patterns
+
+Unix prefers regular expressions. But they are just too hard, too cryptic
+to use, write and understand.
+
+So, netdata supports **simple patterns**.
+
+Simple patterns are a space separated list of words, that can have `*`
+as a wildcard. Each world may use any number of `*`. Simple patterns
+allow **negative** matches by prefixing a word with `!`.
+
+So, `pattern = !*bad* *` will match anything, except all those that
+contain the word `bad`.
+
+Simple patterns are quite powerful: `pattern = *foobar* !foo* !*bar *`
+matches everything containing `foobar`, except strings that start
+with `foo` or end with `bar`.
+
+You can use the netdata command line to check simple patterns,
+like this:
+
+```sh
+# netdata -W simple-pattern '*foobar* !foo* !*bar *' 'hello world'
+RESULT: MATCHED - pattern '*foobar* !foo* !*bar *' matches 'hello world'
+
+# netdata -W simple-pattern '*foobar* !foo* !*bar *' 'hello world bar'
+RESULT: NOT MATCHED - pattern '*foobar* !foo* !*bar *' does not match 'hello world bar'
+
+# netdata -W simple-pattern '*foobar* !foo* !*bar *' 'hello world foobar'
+RESULT: MATCHED - pattern '*foobar* !foo* !*bar *' matches 'hello world foobar'
+```
+
+netdata stops processing to the first positive or negative match
+(left to right). If it is not matched by either positive or negative
+patterns, it is denied at the end.
+