1.6 Exercises

Example 1.1: Modify the echo program to also print os.Args[0], the name of the command that invoked it.

// Exercise 1.1 prints the command name and the command-line arguments
package main

import("fmt";"os";"strings")

func main() {
        fmt.Println(strings.Join(os.Args[0:], " "))
}

Example 1.2: Modify the echo program to print the index and value of each of its arguments, one per line.

// Exercise 1.2 prints each of the command-line arguments with an index, one per line
package main

import("fmt";"os")

func main() {
        for index, value := range os.Args[0:] {
                fmt.Println(index, value)
        }
}

Example 1.3: Experiment to measure the difference in running time between our potentially inefficient versions and the one that uses strings.Join. (Section 1.6 illustrates part of the time package, and Section 11.4 shows how to write benchmark tests for systematic performance evaluation.)