fix: add LookupPath and LookupEnv for cmd module

pkg/cmd/lookup.go

@@ -0,0 +1,38 @@
+package cmd
+
+import (
+	"log"
+	"os"
+	"os/exec"
+)
+
+func LookPathDefault(executableName string, defaultPath string) (binaryPath string) {
+	path, err := exec.LookPath(executableName)
+	if err != nil {
+		return defaultPath
+	}
+	return path
+}
+
+func LookPath(executableName string) (binaryPath string) {
+	path, err := exec.LookPath(executableName)
+	if err != nil {
+		log.Panicln(err.Error())
+	}
+	return path
+}
+
+func LookupEnvDefault(key string, fallback string) string {
+	if value, ok := os.LookupEnv(key); ok {
+		return value
+	}
+	return fallback
+}
+
+func LookupEnv(key string) string {
+	value, ok := os.LookupEnv(key)
+	if !ok {
+		log.Panicf("env key %s not found\n", key)
+	}
+	return value
+}