section .data
    message db "Hello world!", 10
    message_len equ $ - message
    
    error_msg db "Error writing to stdout!", 10
    error_len equ $ - error_msg

section .text
    global _start

_start:
    mov rax, 1
    mov rdi, 1
    mov rsi, message
    mov rdx, message_len
    syscall

    cmp rax, 0
    jl error_handler
    je exit
    jmp exit

error_handler:
    mov rax, 1
    mov rdi, 2
    mov rsi, error_msg
    mov rdx, error_len
    syscall
    mov rax, 60
    mov rdi, 1
    syscall

exit:
    mov rax, 60
    xor rdi, rdi
    syscall

section .data
    filename db "output.txt", 0
    message db "Hello, world!", 10
    message_len equ $ - message
    
    error_open db "Error opening file!", 10
    error_open_len equ $ - error_open
    
    error_write db "Error writing to file!", 10
    error_write_len equ $ - error_write

section .text
    global _start

_start:
    mov rax, 2
    mov rdi, filename
    mov rsi, 0x241
    mov rdx, 0644o
    syscall

    cmp rax, 0
    jl open_error
    mov r8, rax

    mov rax, 1
    mov rdi, r8
    mov rsi, message
    mov rdx, message_len
    syscall

    cmp rax, 0
    jl write_error

    mov rax, 3
    mov rdi, r8
    syscall
    jmp exit

open_error:
    mov rax, 1
    mov rdi, 2
    mov rsi, error_open
    mov rdx, error_open_len
    syscall
    mov rdi, 1
    jmp exit_with_code

write_error:
    mov rax, 1
    mov rdi, 2
    mov rsi, error_write
    mov rdx, error_write_len
    syscall
    mov rdi, 2
    mov rax, 3
    mov rdi, r8
    syscall

exit_with_code:
    mov rax, 60
    syscall

exit:
    mov rax, 60
    xor rdi, rdi
    syscall