[Go] Gets the size (in bytes) of a file

Bytes.go

package main

// We need only this modules
import (
  "os" // For open the file
  "fmt" // For print data
  "io/ioutil" // For read data
)

// A little function for error checking
func check(e error, msg string, args ...interface{}) {
  if e != nil {
    fmt.Printf(msg, args...)
    panic(e)
  }
}

func main() {
  // Holds the error
  var err error
  
  // Open the file, change the name for something in your system
  file, err := os.Open("filename")
  check(err, "Can't open file!")

  // Read the file data and returns it as an array of type byte
  bytes, err := ioutil.ReadAll(file)
  check(err, "Can't read the file!")

  // Prints the size!
  fmt.Printf("File has %d bytes!\n", len(bytes))

  // And close the file
  err = file.Close()
  check(err, "Can't close the file!")
}