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// Package net contains functions to help with network-oriented lookups
package net
import (
"net"
"slices"
)
// LookupIP -
func LookupIP(name string) (string, error) {
i, err := LookupIPs(name)
if err != nil {
return "", err
}
if len(i) == 0 {
return "", nil
}
return i[0], nil
}
// LookupIPs -
func LookupIPs(name string) ([]string, error) {
srcIPs, err := net.LookupIP(name)
if err != nil {
return nil, err
}
// perf note: this slice is not really worth pre-allocating - srcIPs tends
// to be very small, and net.LookupIP is relatively expensive
var ips []string
for _, v := range srcIPs {
if v.To4() != nil {
s := v.String()
if !slices.Contains(ips, s) {
ips = append(ips, s)
}
}
}
return ips, nil
}
// LookupCNAME -
func LookupCNAME(name string) (string, error) {
return net.LookupCNAME(name)
}
// LookupTXT -
func LookupTXT(name string) ([]string, error) {
return net.LookupTXT(name)
}
// LookupSRV -
func LookupSRV(name string) (*net.SRV, error) {
srvs, err := LookupSRVs(name)
if err != nil {
return nil, err
}
return srvs[0], nil
}
// LookupSRVs -
func LookupSRVs(name string) ([]*net.SRV, error) {
_, addrs, err := net.LookupSRV("", "", name)
if err != nil {
return nil, err
}
return addrs, nil
}
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