When using headObject in aws sdk 2 for go. Why it gives undefined?

Thanks in advance . I'm using the following code to get metadata from an s3 object after listing all the object in a bucket . But I don't know why it gives the error undefined: s3.HeadObject when running go run listObjects.go -bucket xxxx -prefix xxxx

I tried two solutions: giving the client as the one created from the config and from the context as in this link appears [1]. BUt both gave the same error. Can you give me any clue?

package main
import (
"context"
"flag"
"fmt"
"log"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/service/s3"
)
var (
bucketName      string
objectPrefix    string
objectDelimiter string
maxKeys         int
)
func init() {
flag.StringVar(&bucketName, "bucket", "", "The `name` of the S3 bucket to list objects from.")
flag.StringVar(&objectPrefix, "prefix", "", "The optional `object prefix` of the S3 Object keys to list.")
flag.StringVar(&objectDelimiter, "delimiter", "",
"The optional `object key delimiter` used by S3 List objects to group object keys.")
flag.IntVar(&maxKeys, "max-keys", 0,
"The maximum number of `keys per page` to retrieve at once.")
}
// Lists all objects in a bucket using pagination
func main() {
flag.Parse()
if len(bucketName) == 0 {
flag.PrintDefaults()
log.Fatalf("invalid parameters, bucket name required")
}
// Load the SDK's configuration from environment and shared config, and
// create the client with this.
cfg, err := config.LoadDefaultConfig(context.TODO())
if err != nil {
log.Fatalf("failed to load SDK configuration, %v", err)
}
client := s3.NewFromConfig(cfg)
// Set the parameters based on the CLI flag inputs.
params := &s3.ListObjectsV2Input{
Bucket: &bucketName,
}
if len(objectPrefix) != 0 {
params.Prefix = &objectPrefix
}
if len(objectDelimiter) != 0 {
params.Delimiter = &objectDelimiter
}
// Create the Paginator for the ListObjectsV2 operation.
p := s3.NewListObjectsV2Paginator(client, params, func(o *s3.ListObjectsV2PaginatorOptions) {
if v := int32(maxKeys); v != 0 {
o.Limit = v
}
})
// Iterate through the S3 object pages, printing each object returned.
var i int
log.Println("Objects:")
for p.HasMorePages() {
i++
// Next Page takes a new context for each page retrieval. This is where
// you could add timeouts or deadlines.
page, err := p.NextPage(context.TODO())
if err != nil {
log.Fatalf("failed to get page %v, %v", i, err)
}
// Log the objects found
// Headobject function is called
for _, obj := range page.Contents {
input := &s3.HeadObjectInput{
Bucket: &bucketName,
Key:    obj.Key,
}
result, err := &s3.HeadObject(client, input)
if err != nil {
panic(err)
}
fmt.Println("Object:", *obj.Key)
}
}
}

./listObjects.go:86:20: undefined: s3.HeadObject

1

Doing the headObject as an auxiliary method works

package main
import (
"context"
"flag"
"fmt"
"log"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/service/s3"
)
var (
bucketName      string
objectPrefix    string
objectDelimiter string
maxKeys         int
)
func init() {
flag.StringVar(&bucketName, "bucket", "", "The `name` of the S3 bucket to list objects from.")
flag.StringVar(&objectPrefix, "prefix", "", "The optional `object prefix` of the S3 Object keys to list.")
flag.StringVar(&objectDelimiter, "delimiter", "",
"The optional `object key delimiter` used by S3 List objects to group object keys.")
flag.IntVar(&maxKeys, "max-keys", 0,
"The maximum number of `keys per page` to retrieve at once.")
}
// Lists all objects in a bucket using pagination
func main() {
flag.Parse()
if len(bucketName) == 0 {
flag.PrintDefaults()
log.Fatalf("invalid parameters, bucket name required")
}
// Load the SDK's configuration from environment and shared config, and
// create the client with this.
cfg, err := config.LoadDefaultConfig(context.TODO())
if err != nil {
log.Fatalf("failed to load SDK configuration, %v", err)
}
client := s3.NewFromConfig(cfg)
// Set the parameters based on the CLI flag inputs.
params := &s3.ListObjectsV2Input{
Bucket: &bucketName,
}
if len(objectPrefix) != 0 {
params.Prefix = &objectPrefix
}
if len(objectDelimiter) != 0 {
params.Delimiter = &objectDelimiter
}
// Create the Paginator for the ListObjectsV2 operation.
p := s3.NewListObjectsV2Paginator(client, params, func(o *s3.ListObjectsV2PaginatorOptions) {
if v := int32(maxKeys); v != 0 {
o.Limit = v
}
})
// Iterate through the S3 object pages, printing each object returned.
var i int
log.Println("Objects:")
for p.HasMorePages() {
i++
// Next Page takes a new context for each page retrieval. This is where
// you could add timeouts or deadlines.
page, err := p.NextPage(context.TODO())
if err != nil {
log.Fatalf("failed to get page %v, %v", i, err)
}
// Log the objects found
// Headobject function is called
for _, obj := range page.Contents {
fmt.Println("Object:", *obj.Key)
OpHeadObject(client, bucketName, *obj.Key)
}
}
}
func OpHeadObject(sess *s3.Client, bucketName, objectName string) {
input := &s3.HeadObjectInput{
Bucket: &bucketName,
Key:    &objectName,
}
resp, err := sess.HeadObject(context.TODO(), input)
if err != nil {
panic(err)
}
fmt.Println(resp.StorageClass) // that you want.
}