Start making pwd

pwd/pwd.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func logicalPWD() {
+	dir, err := os.Getwd()
+	if err != nil {
+		fmt.Printf("%v error: %v", os.Args[0], err)
+		os.Exit(1)
+	}
+	fmt.Println(dir)
+}
+
+func physicalPWD() {
+	fmt.Println("Using physical WD")
+}
+
+func usage() {
+	fmt.Printf("usage: %v [-LP]\n", os.Args[0])
+}
+
+// if there's bs in os.Args[2], it ignores everything else
+func parseArgs() []string {
+	flags := []string{}
+	return flags
+}
+
+// usePhysical parses command-line arguments and determines which mode should be used.
+// If both -L and -P are specified, the last one shall apply.
+// If neither -L nor -P is specified, the pwd utility shall behave as if -L had been specified.
+func usePhysical() bool {
+	if len(os.Args) > 1 {
+		flags := parseArgs()
+		flagsLen := len(flags)
+		lastFlag := flags[flagsLen]
+		if lastFlag == "L" {
+			return false
+		}
+		if lastFlag == "P" {
+			return true
+		}
+	}
+	return false
+}
+
+func main() {
+	if usePhysical() {
+		physicalPWD()
+	} else {
+		logicalPWD()
+	}
+}