Go by Example: URL Parsing

URLs provide a uniform way to locate resources. Here’s how to parse URLs in Go.
	`package main`
	`import ( "fmt" "net" "net/url" )`
	`func main() {`
We’ll parse this example URL, which includes a scheme, authentication info, host, port, path, query params, and query fragment.	`s := "postgres://user:pass@host.com:5432/path?k=v#f"`
Parse the URL and ensure there are no errors.	`u, err := url.Parse(s) if err != nil { panic(err) }`
Accessing the scheme is straightforward.	`fmt.Println(u.Scheme)`
`User` contains all authentication info; call `Username` and `Password` on this for individual values.	`fmt.Println(u.User) fmt.Println(u.User.Username()) p, _ := u.User.Password() fmt.Println(p)`
The `Host` contains both the hostname and the port, if present. Use `SplitHostPort` to extract them.	`fmt.Println(u.Host) host, port, _ := net.SplitHostPort(u.Host) fmt.Println(host) fmt.Println(port)`
Here we extract the `path` and the fragment after the `#`.	`fmt.Println(u.Path) fmt.Println(u.Fragment)`
To get query params in a string of `k=v` format, use `RawQuery`. You can also parse query params into a map. The parsed query param maps are from strings to slices of strings, so index into `[0]` if you only want the first value.	`fmt.Println(u.RawQuery) m, _ := url.ParseQuery(u.RawQuery) fmt.Println(m) fmt.Println(m["k"][0]) }`

Running our URL parsing program shows all the different pieces that we extracted.

$ go run url-parsing.go 
postgres
user:pass
user
pass
host.com:5432
host.com
5432
/path
f
k=v
map[k:[v]]
v

Next example: SHA256 Hashes.