1 files changed, 60 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/pkg/matcher/regexp.go b/src/go/collectors/go.d.plugin/pkg/matcher/regexp.go
new file mode 100644
index 000000000..3a297f3b3
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/pkg/matcher/regexp.go
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package matcher
+
+import "regexp"
+
+// NewRegExpMatcher create new matcher with RegExp format
+func NewRegExpMatcher(expr string) (Matcher, error) {
+	switch expr {
+	case "", "^", "$":
+		return TRUE(), nil
+	case "^$", "$^":
+		return NewStringMatcher("", true, true)
+	}
+	size := len(expr)
+	chars := []rune(expr)
+	var startWith, endWith bool
+	startIdx := 0
+	endIdx := size - 1
+	if chars[startIdx] == '^' {
+		startWith = true
+		startIdx = 1
+	}
+	if chars[endIdx] == '$' {
+		endWith = true
+		endIdx--
+	}
+
+	unescapedExpr := make([]rune, 0, endIdx-startIdx+1)
+	for i := startIdx; i <= endIdx; i++ {
+		ch := chars[i]
+		if ch == '\\' {
+			if i == endIdx { // end with '\' => invalid format
+				return regexp.Compile(expr)
+			}
+			nextCh := chars[i+1]
+			if !isRegExpMeta(nextCh) { // '\' + mon-meta char => special meaning
+				return regexp.Compile(expr)
+			}
+			unescapedExpr = append(unescapedExpr, nextCh)
+			i++
+		} else if isRegExpMeta(ch) {
+			return regexp.Compile(expr)
+		} else {
+			unescapedExpr = append(unescapedExpr, ch)
+		}
+	}
+
+	return NewStringMatcher(string(unescapedExpr), startWith, endWith)
+}
+
+// isRegExpMeta reports whether byte b needs to be escaped by QuoteMeta.
+func isRegExpMeta(b rune) bool {
+	switch b {
+	case '\\', '.', '+', '*', '?', '(', ')', '|', '[', ']', '{', '}', '^', '$':
+		return true
+	default:
+		return false
+	}
+}