command-line-args

044-args.go

@@ -1,12 +0,0 @@
-package main
-
-import ("os"; "fmt")
-
-func main() {
-	argsWithProgram := os.Args
-	argsWithoutProgram := os.Args[1:]
-	arg := os.Args[3]
-	fmt.Println(argsWithProgram)
-	fmt.Println(argsWithoutProgram)
-	fmt.Println(arg)
-}

044-command-line-args.go

@@ -0,0 +1,25 @@
+package main                        // Use `os.Args` to access command-line arguments and
+                                    // the name of the program.
+import ("os"; "fmt")
+
+func main() {
+	argsWithProg := os.Args         // `os.Args` includes the program name as the first
+	argsWithoutProg := os.Args[1:]  // value.
+
+	arg := os.Args[3]               // `Args` are a slice, you can get individual args
+                                    // with normal indexing.
+
+	fmt.Println(argsWithProg)       
+	fmt.Println(argsWithoutProg)
+	fmt.Println(arg)
+}
+
+/*
+$ go build command-line-args        // Build a `command-line-args` binary so that we have
+                                    // the expected program name.
+
+$ ./command-line-args a b c d
+[command-line-args a b c d]       
+[a b c d]
+c
+*/

tool/index.txt

@@ -41,7 +41,7 @@ select
 timeout
 string-fns
 bytes
-args
+command-line-args
 burstable-rate-limiting
 dns
 elapsed