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diff --git a/libnetdata/simple_pattern/README.md b/libnetdata/simple_pattern/README.md new file mode 100644 index 0000000..a90759c --- /dev/null +++ b/libnetdata/simple_pattern/README.md @@ -0,0 +1,43 @@ +<!-- +title: "Netdata simple patterns" +description: "Netdata supports simple patterns, which are less cryptic versions of regular expressions. Use familiar notation for powerful results." +custom_edit_url: https://github.com/netdata/netdata/edit/master/libnetdata/simple_pattern/README.md +--> + +# 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. + +[](<>) |