Code Examples

Golang Convert from Int to Hex

Golang Code Examples
Converting from an Integer to hex is easy in Golang. Since a hex is really just an Integer literal, you can ask the fmt package for a string representation of that integer, using fmt.Sprintf(), and the %x or %X format. package main import ( "fmt" ) func main() { for i := 1; i < 20; i++ { h := fmt.Sprintf("0x%x", i) fmt.Println(h) } } Golang Play Output: 0x1 0x2 0x3 0x4 0x5 0x6 0x7 0x8 0x9 0xa 0xb 0xc 0xd 0xe 0xf 0x10 0x11 0x12 0x13 Convert back to int package main import ( "fmt" "strconv" ) var hex = []string{"1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "10", "11", "12", "13"} func main() { for _, h := range hex { i, _ := strconv. Read more...

Golang Split Host Port to Separate Variables

Golang Code Examples
Getting just the host or port from the “host:port” form is easy using the SplitHostPort function from the net package. Below are some example uses of the function. As seen below, IPv6 addresses in hostport must be enclosed in square brackets. package main import ( "fmt" "net" ) func main() { // IPv4 host, port, err := net.SplitHostPort("172.217.7.14:443") if err != nil { fmt.Println(err) } fmt.Println(host, port) // IPv6 host, port, err = net. Read more...

Golang Convert File Size to a human friendly format

Golang Code Examples
Get file size in human-readable units like kilobytes (KB), Megabytes (MB) or GigaBytes (GB) 1 KilloByte == 1024 Bytes 1 Megabyte == 1024*1024 Bytes 1 GigaByte == 102410241024 Bytes package main import ( "fmt" "io/ioutil" "log" "math" "strconv" ) var ( suffixes [5]string ) func Round(val float64, roundOn float64, places int ) (newVal float64) { var round float64 pow := math.Pow(10, float64(places)) digit := pow * val _, div := math. Read more...

Golang Listing Directory Contents and Sorting by File Modified Time

Golang Code Examples
In this example we will be listing the contents of a directory in go and sorting by date. To get the list of files we will use the ioutil.ReadDir function from the io/ioutil package. This function returns a slice sorted by file name which contains elements of os.FileInfo type which will enable us to get the last modified time. To sort the files we will use the modification time with the sort package along with the After and Before functions from the time package. Read more...

Golang Listing Directory Contents and Sorting by File Name

Golang Code Examples
Listing the contents of a directory in go and sorting by filename. To get the list of file we will use the ReadDir function from the ioutil package. To sort the files we will use the sort package to arrange the filenames alphabetically ascending or descending. package main import ( "fmt" "io/ioutil" "log" "os" "sort" ) // this is the default sort order of golang ReadDir func SortFileNameAscend(files []os.FileInfo) { sort. Read more...