Prompt user after reading from piped input in Golang

I'm having some troubles reading from piped input, and then prompting a user for a further question afterwards. Is this possible to do?

I've created a simplified version of the program here.

I want the user to be able to pipe input in to the program instead of being prompted for it. However, I still want to prompt them with a second question if they don't provide a specific flag in a CLI program I'm writing.

To avoid any prompts, the user could pass in -y (not shown in the program below) along with piping in the text input to skip the "are you sure?" prompt.

package main

import (
    "fmt"
    "os"

    "github.com/AlecAivazis/survey/v2"
)

func main() {
    value := ""

    isPiped, err := isPipedInput()
    if err != nil {
        panic(err)
    }

    if isPiped {
        _, err = fmt.Scanf("%s", &value)
        if err != nil {
            panic(err)
        }
        if value == "" {
            panic(fmt.Errorf("must be greater than 0"))
        }

    } else {
        err = survey.AskOne(&survey.Input{Message: "Enter value followed by [Enter]:"}, &value)
        if err != nil {
            panic(err)
        }
        if value == "" {
            panic(fmt.Errorf("must be greater than 0"))
        }
    }

    shouldProceed := false
    err = survey.AskOne(&survey.Confirm{Message: "Are you sure?"}, &shouldProceed)
    if err != nil {
        panic(err)
    }
    if shouldProceed {
        fmt.Println("Proceeding!", value)
    } else {
        fmt.Println("Not proceeding...", value)
    }
}

func isPipedInput() (bool, error) {
    fi, err := os.Stdin.Stat()
    if err != nil {
        return false, err
    }

    return (fi.Mode() & os.ModeCharDevice) == 0, nil
}

To build:

go build -o main

First use-case that works as expected:

./main
? Enter value followed by [Enter]: foo
? Are you sure? Yes
Proceeding! foo

Second use case that does not work:

echo "foo" | ./main
? Are you sure? (y/N) ^[[23;256Rpanic: EOF

goroutine 1 [running]:
main.main()
        /main.go:40 +0x2b0
^[[8;23R%