test: build test program in nixos config

Signed-off-by: Ophestra <cat@gensokyo.uk>

test/main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	"git.gensokyo.uk/security/fortify/test/sandbox"
+)
+
+func main() {
+	log.SetFlags(0)
+	log.SetPrefix("test: ")
+
+	if len(os.Args) < 2 {
+		log.Fatal("invalid argument")
+	}
+
+	switch os.Args[1] {
+	case "filter":
+		if len(os.Args) != 4 {
+			log.Fatal("invalid argument")
+		}
+
+		if pid, err := strconv.Atoi(strings.TrimSpace(os.Args[2])); err != nil {
+			log.Fatalf("%s", err)
+		} else if pid < 1 {
+			log.Fatalf("%d out of range", pid)
+		} else {
+			sandbox.MustCheckFilter(pid, os.Args[3])
+			return
+		}
+
+	default:
+		(&sandbox.T{FS: os.DirFS("/")}).MustCheckFile(os.Args[1], "/tmp/sandbox-ok")
+		return
+	}
+}