1                                  section .data
     2 00000000 48656C6C6F2C20776F-     	hello     db	'Hello, world!',10	; Our dear string
     3 00000009 726C64210A         
     4                                  	helloLen  equ	$ - hello		; Length of our dear string
     5                                  
     6                                  section	.text
     7                                      global _start
     8                                  
     9                                  _start:
    10 00000000 5B                      	pop	ebx		; argc (argument count)
    11 00000001 5B                      	pop	ebx		; argv[0] (argument 0, the program name)
    12 00000002 5B                      	pop	ebx		; The first real arg, a filename
    13                                  
    14 00000003 B808000000              	mov	eax,8		; The syscall number for creat() (we already have the filename in ebx)
    15 00000008 B9A4010000              	mov	ecx,00644Q	; Read/write permissions in octal (rw_rw_rw_)
    16 0000000D CD80                    	int	80h		; Call the kernel
    17                                  				; Now we have a file descriptor in eax
    18                                  
    19 0000000F 85C0                    	test	eax,eax		; Lets make sure the file descriptor is valid
    20 00000011 7805                    	js	skipWrite	; If the file descriptor has the sign flag
    21                                  				;  (which means it's less than 0) there was an oops,
    22                                  				;  so skip the writing. Otherwise call the filewrite "procedure"
    23 00000013 E809000000              	call	fileWrite
    24                                  
    25                                  skipWrite:
    26 00000018 89C3                    	mov	ebx,eax		; If there was an error, save the errno in ebx
    27 0000001A B801000000              	mov	eax,1		; Put the exit syscall number in eax
    28 0000001F CD80                    	int	80h		; Bail out
    29                                  
    30                                  ; proc fileWrite - write a string to a file
    31                                  fileWrite:
    32 00000021 89C3                    	mov	ebx,eax		; sys_creat returned file descriptor into eax, now move into ebx
    33 00000023 B804000000              	mov	eax,4		; sys_write
    34                                  				; ebx is already set up
    35 00000028 B9[00000000]            	mov	ecx,hello	; We are putting the ADDRESS of hello in ecx
    36 0000002D BA0E000000              	mov	edx,helloLen	; This is the VALUE of helloLen because it's a constant (defined with equ)
    37 00000032 CD80                    	int	80h
    38                                  
    39 00000034 B806000000              	mov	eax,6		; sys_close (ebx already contains file descriptor)
    40 00000039 CD80                    	int	80h
    41 0000003B C3                      	ret
    42                                  ; endp fileWrite
    43