O_RDONLY = syscall.O_RDONLY // open the file read-only.
O_WRONLY = syscall.O_WRONLY // open the file write-only.
O_RDWR = syscall.O_RDWR // open the file read-write.
- O_APPEND = syscall.O_APPEND // open the file append-only.
+ O_APPEND = syscall.O_APPEND // append data to the file when writing.
O_ASYNC = syscall.O_ASYNC // generate a signal when I/O is available.
O_CREAT = syscall.O_CREAT // create a new file if none exists.
O_EXCL = syscall.O_EXCL // used with O_CREAT, file must not exist