Golang : Test file read write permission example




Problem : You need to test if a file has the correct write or read permission before performing write or read operation. How to do that? Solution : Use os.OpenFile() function and check the error with os.IsPermission() to see if a file has permission denied error. For example : To test if a file has write permission : (do not run this program as root or super user) package main import ( "fmt" "os" ) func main() { fileName := "file.txt" file, err := os.OpenFile(fileName, os.O_WRONLY, 0666) if err != nil { if os.IsPermission(err) { fmt.Println("Unable to write to ", fileName) fmt.Println(err) os.Exit(1) } } file.Close() } To test if a file has read permission : (do not run this program as root or super user) package main import ( "fmt" "os" ) func main() { fileName := "file.txt" file, err = os.OpenFile(fileName, os.O_RDONLY, 0666) if err != nil { if os.IsPermission(err) { fmt.Println("Unable to read from ", fileName) fmt.Println(err) os.Exit(1) } } file.Close() } References : https://golang.org/pkg/os/#IsPermission https://www.socketloop.com/tutorials/golang-check-if-a-file-exist-or-not

  See also : Golang : Get file permission



Tags : golang write-permission read-permission os-openfile os-ispermission

Adam Ng By Adam Ng

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