refactor: use pflags

.golangci.yml

@@ -0,0 +1,18 @@
+linters:
+  enable-all: true
+
+  disable:
+  - maligned
+  - scopelint
+  - interfacer
+  - ifshort
+  - exhaustivestruct
+  - golint
+  - forbidigo
+  - testpackage
+  - goerr113
+  - paralleltest
+  - gomnd
+  - varnamelen
+  - wrapcheck
+  - wsl

cmd/main.go

@@ -1,53 +1,83 @@
 package main
 
 import (
-	"flag"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/blaskovicz/go-cryptkeeper"
+	"github.com/spf13/pflag"
 )
 
-var (
-	operation string
-	key       string
-	value     string
-)
-
-func init() {
-	flag.StringVar(&operation, "o", "", "operation: encrypt or decrypt")
-	flag.StringVar(&key, "k", "", "encryption key")
-	flag.StringVar(&value, "v", "", "target value of the operation")
-
-	flag.Parse()
-}
-
 func main() {
-	if operation == "" || key == "" || value == "" {
-		flag.PrintDefaults()
+	if err := run(); err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
+}
 
-	if err := cryptkeeper.SetCryptKey([]byte(key)); err != nil {
-		fmt.Println(err)
-		os.Exit(1)
+func run() error {
+	op, k, v, err := getFlags()
+	if err != nil {
+		return err
+	}
+
+	if err := cryptkeeper.SetCryptKey([]byte(k)); err != nil {
+		return err
 	}
 
 	var result string
-	var err error
-	switch operation {
+
+	switch op {
 	case "encrypt":
-		result, err = cryptkeeper.Encrypt(value)
+		result, err = cryptkeeper.Encrypt(v)
 	case "decrypt":
-		result, err = cryptkeeper.Decrypt(value)
+		result, err = cryptkeeper.Decrypt(v)
 	default:
-		fmt.Println("Invalid operation: ", operation)
-		os.Exit(1)
+		return usageError(fmt.Sprintf("Invalid operation: %s", op))
 	}
+
 	if err != nil {
-		fmt.Println(err)
-		os.Exit(1)
+		return err
 	}
 
 	fmt.Println(result)
+
+	return nil
+}
+
+func getFlags() (string, string, string, error) {
+	o := pflag.String("o", "", "operation: encrypt or decrypt")
+	k := pflag.String("k", "", "encryption key")
+	v := pflag.String("v", "", "target value of the operation")
+
+	var errs []string
+	if empty(o) {
+		errs = append(errs, "operation flag missing")
+	}
+	if empty(k) {
+		errs = append(errs, "key flag missing")
+	}
+	if empty(v) {
+		errs = append(errs, "value flag missing")
+	}
+	if len(errs) > 0 {
+		return "", "", "", usageError(strings.Join(errs, "\n"))
+	}
+
+	return *o, *k, *v, nil
+}
+
+func empty(s *string) bool {
+	if s == nil || *s == "" {
+		return true
+	}
+
+	return false
+}
+
+type usageError string
+
+func (ue usageError) Error() string {
+	return fmt.Sprintf("%s\n\nUsage of %s:\n%s", string(ue), os.Args[0], pflag.CommandLine.FlagUsages())
 }

go.mod

@@ -3,3 +3,5 @@ module github.com/agukrapo/go-cryptkeeper-cli
 go 1.19
 
 require github.com/blaskovicz/go-cryptkeeper v0.0.0-20190930202326-736b85609f91
+
+require github.com/spf13/pflag v1.0.5

go.sum

@@ -1,2 +1,4 @@
 github.com/blaskovicz/go-cryptkeeper v0.0.0-20190930202326-736b85609f91 h1:htfkBBjhD5gi6WkDbU1Eq0qE67h0vAmeb3HWtn/Qdlc=
 github.com/blaskovicz/go-cryptkeeper v0.0.0-20190930202326-736b85609f91/go.mod h1:aLh4O6/WQZYvQ/LKF4hPidOh/oofXPjIShojoLvbrjg=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=