For example: this simple test Go program compiles to an EXE of ~2 MB on Windows 7 with Go 1.9:

    // From: https://gobyexample.com/reading-files

    package main
    import (
        "bufio"
        "fmt"
        "io"
        "io/ioutil"
        "os"
    )

    func check(e error) {
        if e != nil {
            panic(e)
        }
    }

    func main() {

        dat, err := ioutil.ReadFile("dat")
        check(err)
        fmt.Print(string(dat))

        f, err := os.Open("dat")
        check(err)

        b1 := make([]byte, 5)
        n1, err := f.Read(b1)
        check(err)
        fmt.Printf("%d bytes: %s\n", n1, string(b1))

        o2, err := f.Seek(6, 0)
        check(err)
        b2 := make([]byte, 2)
        n2, err := f.Read(b2)
        check(err)
        fmt.Printf("%d bytes @ %d: %s\n", n2, o2, string(b2))

        o3, err := f.Seek(6, 0)
        check(err)
        b3 := make([]byte, 2)
        n3, err := io.ReadAtLeast(f, b3, 2)
        check(err)
        fmt.Printf("%d bytes @ %d: %s\n", n3, o3, string(b3))
        
         _, err = f.Seek(0, 0)
        check(err)

        r4 := bufio.NewReader(f)
        b4, err := r4.Peek(5)
        check(err)
        fmt.Printf("5 bytes: %s\n", string(b4))

       f.Close()
    }