add arguments parser

go.sum

@@ -0,0 +1,2 @@
+github.com/akamensky/argparse v1.3.1 h1:kP6+OyvR0fuBH6UhbE6yh/nskrDEIQgEA1SUXDPjx4g=
+github.com/akamensky/argparse v1.3.1/go.mod h1:S5kwC7IuDcEr5VeXtGPRVZ5o/FdhcMlQz4IZQuw64xA=

main.go

@@ -1,9 +1,41 @@
 package main
 
 import (
+	"github.com/akamensky/argparse"
 	"log"
+	"os"
+	"fmt"
 )
 
-func main() {
-	log.Printf("packer")
+// parseArguments - get needed arguments to launch the `packer`
+// returns 3 strings :
+// * regex
+// * outputPath
+// * directory
+func parseArguments() (string, string, string, error) {
+	parser := argparse.NewParser("packer", "packer - zip file where filenames match with a regex")
+	var err error
+
+	regex := parser.String("r", "regex", &argparse.Options{Required: true, Help: "filename Regex"})
+	outputPath := parser.String("o", "output-path", &argparse.Options{Required: true, Help: "zip output path (including zip name)"})
+	directory := parser.String("d", "directory", &argparse.Options{Required: false, Help: "root directory to check files", Default: "."})
+
+	parseError := parser.Parse(os.Args)
+	if parseError != nil {
+		err = fmt.Errorf("parsing error: %s", parseError)
+	}
+
+	return *regex, *outputPath, *directory, err
+}
+
+func main() {
+
+	regex, directory, outputPath, err := parseArguments()
+
+	if err != nil {
+		log.Fatal("error while parsing args : ", err)
+	}
+
+	log.Printf("looking for file '%s' in '%s' ...", regex, directory)
+	log.Printf("files zipped in %s", outputPath)
 }