add string matching e.g 'like %str%'

engine/filter.go

@@ -2,6 +2,7 @@ package engine
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/tidwall/gjson"
 )
@@ -66,6 +67,24 @@ func match(filter gjson.Result, data string) (result bool, err error) {
 						result = false
 						return result
 
+					case "$st": // is start with
+						if !strings.HasPrefix(dv.String(), sqv.String()) {
+							result = false
+						}
+						return result
+
+					case "$en": // is end with
+						if !strings.HasSuffix(dv.String(), sqv.String()) {
+							result = false
+						}
+						return result
+
+					case "$c": // is contains
+						if !strings.Contains(dv.String(), sqv.String()) {
+							result = false
+						}
+						return result
+
 					default:
 						err = fmt.Errorf("unknown %s operation", sqk.Value())
 						//fmt.Println("..wher here", sqk.Value(), sqk.Type)