I want to create a hardlink to a file using golang. os.Link() tells me, that windows is not supported. Therefore i tried to use os.exec, to call "mklink.exe".
cmd := exec.Command("mklink.exe", "/H", hardlink_path, file_path)
err := cmd.Run()
However, it tells me, that it can't find mklink.exe in %PATH%. This baffels me, since i can call it using cmd.
Next i tried to call it indirectly via cmd:
cmd := exec.Command("cmd.exe", "mklink.exe", "/H", hardlink_path, file_path)
err := cmd.Run()
Now it does not return any error, however, it also doesn't create a hardlink. Any suggestions?
For example,
package main
import (
"fmt"
"os"
"os/exec"
)
func main() {
hardlink_path := `link.hard`
file_path := `link.go`
_, err := os.Stat(file_path)
if err != nil {
fmt.Println(err)
return
}
os.Remove(hardlink_path)
cmd := exec.Command("cmd", "/c", "mklink", "/H", hardlink_path, file_path)
out, err := cmd.CombinedOutput()
if err != nil {
fmt.Println(err)
return
}
fmt.Print(string(out))
}
Output:
Hardlink created for link.hard <<===>> link.go
Golang support for native Windows hard links was added in Go 1.4. Specifically, this commit makes the following snippet work:
err := os.Link("original.txt", "link.txt")
Beware that not all Windows file systems support hard links. Currently NTFS and UDF support it, but FAT32, exFAT and the newer ReFS do not.
Full example code:
package main
import (
"log"
"os"
"io/ioutil"
)
func main() {
err := ioutil.WriteFile("original.txt", []byte("hello world"), 0600)
if err != nil {
log.Fatalln(err)
}
err = os.Link("original.txt", "link.txt")
if err != nil {
log.Fatalln(err)
}
}