# Misc notes
## SSH X11 forward
### To codespace from Windows
* Launch VcXsrv
* set DISPLAY=127.0.0.1:0.0

### To codespace from Linux
* sudo apt-get install xorg openbox
* export DISPLAY localhost:0.0
* not sure
### Command
* gh codespace list
* To get the name
* gh codespace -c name ssh -- -Y
### In codespace
* sudo apt-get install xauth

// devcontainer.json
{
  "features": {
    "sshd": "latest"
  }
}

## git ask password
From ? version, OpenSSH make ssh-rsa deprecated, it is still supported but is disabled by default.

Use ```ssh -vT user@hostname``` to check the details.

Solution
* Generate key other type of key
* Enable rsa(not tested)

## Mod vs Remainder
* Most programming language implement remainder
* C99 spec: a == (a/b)*b+a%b
* IEEE754 also define remainder of floating point
* C# '%' operator is different from spec
> This method of computing the remainder is analogous to that used for integer operands, but different from the IEEE 754 specification. If you need the remainder operation that complies with the IEEE 754 specification, use the Math.IEEERemainder method.