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Port package which finds available ports or checks if a port is available
package port
import (
"net"
"strconv"
)
// New gets an available port
func New() (port int, err error) {
// Create a new server without specifying a port
// which will result in an open port being chosen
server, err := net.Listen("tcp", ":0")
// If there's an error it likely means no ports
// are available or something else prevented finding
// an open port
if err != nil {
return 0, err
}
// Defer the closing of the server so it closes
defer server.Close()
// Get the host string in the format "127.0.0.1:4444"
hostString := server.Addr().String()
// Split the host from the port
_, portString, err := net.SplitHostPort(hostString)
if err != nil {
return 0, err
}
// Return the port as an int
return strconv.Atoi(portString)
}
// Check if a port is available
func Check(port int) (status bool, err error) {
// Concatenate a colon and the port
host := ":" + strconv.Itoa(port)
// Try to create a server with the port
server, err := net.Listen("tcp", host)
// if it fails then the port is likely taken
if err != nil {
return false, err
}
// close the server
server.Close()
// we successfully used and closed the port
// so it's now available to be used again
return true, nil
}
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