bits 32

section .data

stdout equ 1

sys_write equ 4
sys_exit equ 1

kernel equ 0x80

program db "Program: ", 0
programlen equ $-program

nl db "", 10, 0
nllen equ $-nl

section .bss

scriptname resd 1
scriptnamelen resd 1

section .text

global _start

strlen:							; eax: a string ending in 0
	push eax						; cache eax

	.strloop:
		mov bl, byte [eax]
		cmp bl, 0
		je .strret						; return len if bl == 0
		inc eax							; else eax++
		jmp .strloop

	.strret:
		pop ebx							; ebx = cached eax
		sub eax, ebx					; eax -= ebx
		ret								; eax = len

_start:
	mov eax, esp
	add eax, 4
	mov eax, [eax]
	mov dword [scriptname], eax

	mov eax, sys_write
	mov ebx, stdout
	mov ecx, program
	mov edx, programlen
	int kernel

	mov dword eax, [scriptname]
	call strlen
	mov dword [scriptnamelen], eax

	mov eax, sys_write
	mov ebx, stdout
	mov dword ecx, [scriptname]
	mov dword edx, [scriptnamelen]
	int kernel

	mov eax, sys_write
	mov ebx, stdout
	mov ecx, nl
	mov edx, nllen
	int kernel

	mov eax, sys_exit
	mov ebx, 0
	int kernel