在Go中无法读取大于1024个字符的输入

Question

I am using fmt.Scanf to read a string input in Golang. But the command stalls when we pass in a large input (>1024 characters). I am using Go version go1.8.3 darwin/amd64.

Here is the code

package main

import "fmt"

func main() {
    var s string
    fmt.Scanf("%s", &s)
    fmt.Println(s)
}

Here is the payload that fails https://pastebin.com/raw/fJ4QAZUZ

Go seems to take input till Jy in that payload which marks 1024 number of characters. So is 1024 a limit or what?

PS - I had already tampered the encoded cookie at that link, so no worries.

Answer 1

It's not the limit of the fmt package or fmt.Scanf(), this example properly scans more than 3KB:

// src is a looooong text (>3KB)

var s string
fmt.Println(len(src))
fmt.Sscanf(src, "%s", &s)
fmt.Println(len(s))

Try it on the Go Playground

It's most likely the limit of your terminal. I also tried your unmodified version, pasted more than 10KB of text, and the result was 4096 bytes (Ubuntu linux 16.04, Bash).