44 lines
624 B
Go
44 lines
624 B
Go
package main
|
|
|
|
import (
|
|
"context"
|
|
"flag"
|
|
"fmt"
|
|
"log"
|
|
"net"
|
|
)
|
|
|
|
func lookupHost(host string) error {
|
|
r := &net.Resolver{}
|
|
cname, err := r.LookupCNAME(context.Background(), host)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if cname != host {
|
|
fmt.Printf("%s is a CNAME for %s\n", host, cname)
|
|
host = cname
|
|
}
|
|
|
|
addrs, err := r.LookupHost(context.Background(), host)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for _, addr := range addrs {
|
|
fmt.Printf("\t%s\n", addr)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func main() {
|
|
flag.Parse()
|
|
|
|
for _, arg := range flag.Args() {
|
|
if err := lookupHost(arg); err != nil {
|
|
log.Printf("%s: %s", arg, err)
|
|
}
|
|
}
|
|
}
|