Golang

Why I chose golang

• Golang is open-source and backed up by a large corporation
• Golang syntax is simple
• Good cross platform support
• It is a compiled language
• Compiles into a single binary, therefore can install anywhere without installing any dependencies.
• Static type system. Tells you about type mistakes on compiling
• Performs better than python [source]
• Go has garbage collection (whatever that means)
• Go has a concurrency model (whatever that means)
• Go is more elegant than C++
• Compile errors are more readable than other languages

Tips & tricks

• go build -ldflags "-w -s" makes the executable smaller
• go get -u golang.org/x/lint/golint for linting go code
• For encoding, encoding/json and encoding/xml
• go build -pie introduces ASLR.

Goroutines

go func(a int){
	...
} (x)

Port scanner

conn, err := net.Dial("tcp", "scanme.nmap.org:80")
if err != nil {
	fmt.Printf("Connection failed on port 80")
}

conn.Close()

Wait

// creates the struct
var wg sync.WaitGroup 

for {
	// +1 to the counter
	wg.Add(1)

	go func(j int){
		// at the end of the func, -1
		defer wg.Done()
		...
	} (a)
}

// waits for the counter to be 0
wg.Wait()

Worker functions

func worker(ports chan int, wg *sync.WaitGroup){
	for p := range ports {
		fmt.Println(p)
		wg.Done()
	}
}

Buffered channel

ch := make(chan int, 100)

Pointers

value := 21

address = &value

fmt.Println(*address) // = 21

• (*p).field is the same as p.field
• v.Scale(5) is the same as (&v).Scale(5)

Find issues

golint and go vet