Transfering money from a pda to a user wallet with native rust

Question

Sorry for a noob question but im writing a solana program without anchor. And I'm having a problem with transfering sol from pda to a wallet in a program.

pub fn process_instruction(
    program_id: &Pubkey,
    accounts: &[AccountInfo],
    instruction_data: &[u8]
) -> ProgramResult {
    let accounts_iter = &mut accounts.iter();
    let account_user = next_account_info(accounts_iter)?;
    let account_pda = next_account_info(accounts_iter)?;

    let (pda, bump_seed) = Pubkey::find_program_address(&[b"stack"], program_id);

    let cost = Rent::get()?.minimum_balance(300 as usize);

    let create_pda_ix = system_instruction::create_account(
        &account_user.key,
        &account_pda,
        cost,
        300,
        program_id,
    );

    invoke_signed(
        &create_pda_ix,
        &[account_user.clone(), account_pda.clone()],
        &[&[b"stack", &[bump_seed]]], 
    )?;

    // How do i transfer money from the pda to a user wallet

    Ok(())
}

invoking a normal transaction didnt work. What do i do i cant find a native example of this problem.

Answer 1

Since the PDA is owned by your program, subtract the lamports from the PDA account and add an equal amount to another account.

For example:

    **account_pda.try_borrow_mut_lamports()? -= cost;
    **account_user.try_borrow_mut_lamports()? += cost;

https://github.com/solana-developers/program-examples/blob/main/basics/transfer-sol/native/program/src/instruction.rs#L23-L36