Golang - Converting uint to os.FileMode

Question

I'm trying to get user permissions for a file from the user as a string and convert it into type os.FileMode.

So, after I get the permission "0644" and convert it, it becomes 644. I am using this as a parameter to ioutil.WriteFile.

This is what I'm doing.

data["perm"] = "0644"
tempval, err2 = strconv.ParseUint(data["Perm"], 10, 32)
// tempval is 644

I'm not getting the right permissions.

I get --w----r-- instead of -rw-r--r-- I've been trying to find a workaround.

So, how exactly do I achieve this?

Answer 1

tempval, err2 = strconv.ParseUint(data["Perm"], 10, 32)

You're explicitly asking for base 10 here. If you want base 8 (which is the traditional base for unix file modes), then you need to use 8 in the second parameter. Or better, use base 0, and it'll automatically choose base 8 due to the leading 0. See the docs on strconv.ParseInt for how "base 0" works.