Go ReadString issues: The filename, directory name, or volume label syntax is incorrect

Question

can anyone figure this out? I think the problem might be in the readstring() argument when being passed to the create file function. I tried resolving it by stripping '\n' but the error remains. Is there a workaround other than readstring()? Because I think it's the one causing issues. Thank you

package main

import (
    "fmt"
    "bufio"
    "log"
    "strings"
    //"io/ioutil"
    "os"
)

func main() {
    fmt.Print("Enter filename to create: ")

    reader := bufio.NewReader(os.Stdin)

    text, _ := reader.ReadString('\n')
    text = strings.TrimSuffix(text, "\n")


    if len(text) > 3 {
        //newFile, err := os.Create(text)
        fmt.Println("Name:"+text)
        createFile(text)
    } else {
        fmt.Println("invalid filename")
    }

}

func createFile(fileName string){
    var newFile *os.File
    var err error


    fmt.Println(fileName)

    newFile, err = os.Create(fileName)
    if err != nil {
        log.Fatal(err)
    }
    newFile.Close()
}

---

Ok for those who are new to this problem, I've manage to find a workaround using scanf. So consider this problem solved.

Answer 1

Start with basic debugging techniques: check for errors and check input.

---

Replace

text, _ := reader.ReadString('\n')

with

text, err := reader.ReadString('\n')
if err != nil {
    log.Fatal(err)
}
fmt.Printf("%q\n", text)

For example,

so1.go:

package main

import (
    "bufio"
    "fmt"
    "log"
    "strings"
    //"io/ioutil"
    "os"
)

func main() {
    fmt.Print("Enter filename to create: ")

    reader := bufio.NewReader(os.Stdin)

    text, err := reader.ReadString('\n')
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("%q\n", text)

    text = strings.TrimSuffix(text, "\n")

    if len(text) > 3 {
        //newFile, err := os.Create(text)
        fmt.Println("Name:" + text)
        createFile(text)
    } else {
        fmt.Println("invalid filename")
    }

}

func createFile(fileName string) {
    var newFile *os.File
    var err error

    fmt.Println(fileName)

    newFile, err = os.Create(fileName)
    if err != nil {
        log.Fatal(err)
    }
    newFile.Close()
}

Output:

>go run so1.go
Enter filename to create: test.file
"test.file\r\n"
Name:test.file
test.file
: The filename, directory name, or volume label syntax is incorrect.
exit status 1

On Windows, the line is terminated with "\r\n".

---

Replace

text = strings.TrimSuffix(text, "\n")

with

text = strings.TrimSuffix(text, "\n")
text = strings.TrimSuffix(text, "\r")

For example,

so2.go:

package main

import (
    "bufio"
    "fmt"
    "log"
    "strings"
    //"io/ioutil"
    "os"
)

func main() {
    fmt.Print("Enter filename to create: ")

    reader := bufio.NewReader(os.Stdin)

    text, err := reader.ReadString('\n')
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("%q\n", text)

    text = strings.TrimSuffix(text, "\n")
    text = strings.TrimSuffix(text, "\r")

    if len(text) > 3 {
        //newFile, err := os.Create(text)
        fmt.Println("Name:" + text)
        createFile(text)
    } else {
        fmt.Println("invalid filename")
    }

}

func createFile(fileName string) {
    var newFile *os.File
    var err error

    fmt.Println(fileName)

    newFile, err = os.Create(fileName)
    if err != nil {
        log.Fatal(err)
    }
    newFile.Close()
}

Output:

>go run so2.go
Enter filename to create: test.file
"test.file\r\n"
Name:test.file
test.file

---

Now that the program works, remove this debugging statement:

fmt.Printf("%q\n", text)

Answer 2

Go to cmd, type command:

go env -w GO111MODULE=off

Finally, use command:

go run ./