Golang : Set and Get HTTP request headers example
Couple of examples on how to set and get HTTP request headers in Golang.
Example of setting HTTP request header.
To set User-Agent for your Golang application, first create a client and set client's request header with [your user-agent name] before executing the request.
For instance :
client := &http.Client{}
request, err := http.NewRequest("GET", "http://example.com", nil)
if err != nil {
log.Fatalln(err)
}
request.Header.Set("User-Agent", "[your user-agent name]")
resp, err := client.Do(req)
Example of getting file download size
response, err := http.Head(url)
if err != nil {
log.Println("Error while downloading", url, ":", err)
}
length, _ := strconv.Atoi(response.Header.Get("Content-Length"))
sourceSize := int64(length)
Example of getting HTTP request header User-Agent information with Header.Get()
method
package main
import (
"fmt"
"net/http"
)
func getUserAgent(w http.ResponseWriter, r *http.Request) {
ua := r.Header.Get("User-Agent")
fmt.Printf("user agent is: %s \n", ua)
w.Write([]byte("user agent is " + ua))
}
func main() {
http.HandleFunc("/", getUserAgent)
http.ListenAndServe(":8080", nil)
}
Apart from User-Agent, here is a list of common HTTP headers :
"accept"
"accept-charset"
"accept-encoding"
"accept-language"
"accept-ranges"
"age"
"access-control-allow-origin"
"allow"
"authorization"
"cache-control"
"content-disposition"
"content-encoding"
"content-language"
"content-length"
"content-location"
"content-range"
"content-type"
"cookie"
"date"
"etag"
"expect"
"expires"
"from"
"host"
"if-match"
"if-modified-since"
"if-none-match"
"if-unmodified-since"
"last-modified"
"link"
"location"
"max-forwards"
"proxy-authenticate"
"proxy-authorization"
"range"
"referrer"
"refresh"
"retry-after"
"server"
"set-cookie"
"strict-transport-security"
"transfer-encoding"
"user-agent"
"vary"
"via"
"www-authenticate"
References :
https://www.socketloop.com/references/golang-net-http-canonicaheaderkey-function-example
https://www.socketloop.com/tutorials/golang-how-to-get-http-request-header-information
https://www.socketloop.com/tutorials/golang-how-to-set-or-add-header-http-responsewriter
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+7.2k Golang : HTTP Server Example
+20k Golang : GORM create record or insert new record into database example
+9.7k Golang : Command line file upload program to server example
+38.3k Golang : UDP client server read write example
+6.8k Javascript : Put image into Chrome browser's console
+14k Golang : Get timezone offset from date or timestamp
+10.8k Golang : Determine if time variables have same calendar day
+81.7k Golang : How to convert character to ASCII and back
+21.7k Golang : Calculate time different
+7.5k Golang : Count leading or ending zeros(any item of interest) example
+7.3k Swift : Convert (cast) Character to Integer?
+7.3k Useful methods to access blocked websites