OpenFile (Append) in Go
OpenFile is the generalized open call; most users will use Open or Create instead. It opens the named file with specified flag (O_RDONLY etc.). If the file does not exist, and the O_CREATE flag is passed, it is created with mode perm (before umask). If successful, methods on the returned File can be used for I/O. If there is an error, it will be of type *PathError.
package main
import (
"log"
"os"
)
func main() {
// If the file doesn't exist, create it, or append to the file
f, err := os.OpenFile("access.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
log.Fatal(err)
}
if _, err := f.Write([]byte("appended some data\n")); err != nil {
f.Close() // ignore error; Write error takes precedence
log.Fatal(err)
}
if err := f.Close(); err != nil {
log.Fatal(err)
}
}