v1.14.3

ADDED:
* Convenience function to return a namespace FD and its type from a
  namespace ID (Linux only)

errs/errs_linux.go

@@ -0,0 +1,9 @@
+package errs
+
+import (
+	"errors"
+)
+
+var (
+	ErrInvalidNs error = errors.New("invalid namespace identifier")
+)

funcs_linux.go

@@ -1,11 +1,14 @@
 package sysutils
 
 import (
-	`fmt`
-	`os`
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
 
-	`golang.org/x/sys/unix`
-	`r00t2.io/sysutils/envs`
+	"golang.org/x/sys/unix"
+	"r00t2.io/sysutils/envs"
+	"r00t2.io/sysutils/errs"
 )
 
 // GetIDState returns current ID/elevation information. An IDState should *not* be explicitly created/defined.
@@ -48,3 +51,27 @@ func GetIDState() (ids IDState) {
 
 	return
 }
+
+// NsToFD splits a namespace identifier (e.g. `net:[12345]`) to its type (e.g. `net`) and FD (e.g. `12345`).
+func NsToFD(ns string) (typ string, fd uint64, err error) {
+
+	var fields []string
+
+	fields = strings.SplitN(ns, ":", 2)
+
+	if len(fields) != 2 {
+		err = errs.ErrInvalidNs
+		return
+	}
+
+	fields[1] = strings.TrimPrefix(fields[1], "[")
+	fields[1] = strings.TrimSuffix(fields[1], "]")
+
+	if fd, err = strconv.ParseUint(fields[1], 10, 64); err != nil {
+		return
+	}
+
+	typ = fields[0]
+
+	return
+}