英文:
How to use URL from user input in Go?
问题
我几乎完全不了解Go语言，我目前的问题是从用户输入中读取URL并将其存储到一个变量中，以便作为参数传递给http.Get()函数。
以下是代码：
package main
import (
"bufio"
"fmt"
"net/http"
"os"
"reflect"
)
func main() {
reader := bufio.NewReader(os.Stdin)
fmt.Print("Enter URL: ")
txt, _ := reader.ReadString('\n')
fmt.Println(reflect.TypeOf(txt)) // 获取对象类型
//url := fmt.Sprintf("http://%s",txt)
url := "http://google.com"
fmt.Println(reflect.TypeOf(url)) // 获取对象类型
resp, err := http.Get(url)
if err != nil {
fmt.Printf("%s", err)
os.Exit(1)
} else {
fmt.Printf("%s\n", resp.Status)
}
}
这段代码运行得很好：
d:\Go\bin>get_status
Enter URL: google.com
string
string
200 OK
但是，当我取消注释代码的第16行（同时注释掉第17行）：
url := fmt.Sprintf("%s",txt)
//url := "http://google.com"
以便使用用户输入的URL时，我遇到了一个问题：
d:\Go\bin>get_status
Enter URL: google.com
string
string
Get http://google.com: dial tcp: GetAddrInfoW: No such host is known.
我的代码有什么问题？请帮我解决疑惑！ 
更新：
添加import "strings"，并使用url := strings.TrimSpace(fmt.Sprintf("http://%s",txt))修复了问题。
ReadString函数会读取输入直到第一个分隔符出现为止，返回包含分隔符在内的数据的字符串。
英文:
I am almost absolutely new to Go language and my current problem is to read URL from user input into a variable to be passed as an argument to http.Get().
The following code
package main
import (
"bufio"
"fmt"
"net/http"
"os"
"reflect"
)
func main() {
reader := bufio.NewReader(os.Stdin)
fmt.Print("Enter URL: ")
txt, _ := reader.ReadString('\n')
fmt.Println(reflect.TypeOf(txt)) // Get object type
//url := fmt.Sprintf("http://%s",txt)
url := "http://google.com"
fmt.Println(reflect.TypeOf(url)) // Get object type
resp, err := http.Get(url)
if err != nil {
fmt.Printf("%s", err)
os.Exit(1)
} else {
fmt.Printf("%s\n", resp.Status)
}
}
works perfectly:
d:\Go\bin>get_status
Enter URL: google.com
string
string
200 OK
but when I uncomment line 16 of the code (while commenting out line 17)
url := fmt.Sprintf("%s",txt)
//url := "http://google.com"
to use URL from user input, I get a problem:
d:\Go\bin>get_status
Enter URL: google.com
string
string
Get http://google.com
: dial tcp: GetAddrInfoW: No such host is known.
What could be wrong with my code? Please soothe my pain!
Upd:
import "strings" plus url := strings.TrimSpace(fmt.Sprintf("http://%s",txt)) fixed the problem.
> ReadString reads until the first occurrence of delim in the input,
> returning a string containing the data up to and including the
> delimiter.
答案1
得分: 1
好的，看起来ReadString包括分隔符，所以你可以使用strings包中的TrimSpace函数。这对我来说似乎起作用了。
url = strings.TrimSpace(url)
英文:
Alright, so it appears that ReadString includes the delimiter, so you can use TrimSpace from the strings package. This seemed to do the trick for me.
url = strings.TrimSpace(url)
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