Adding upstream version 1.12.0.upstream/1.12.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/libnetdata/simple_pattern/README.md b/libnetdata/simple_pattern/README.md
new file mode 100644
index 0000000..79a7131
--- /dev/null
+++ b/libnetdata/simple_pattern/README.md
@@ -0,0 +1,38 @@
+## 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.
+
+
+[![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Flibnetdata%2Fsimple_pattern%2FREADME&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)]()