;
;
;
section .bss
;
section .data
;
filename: db "buffer.txt"
errMsg: db 'Can't open the file', 10; Error message if buffer.txt is not found, 10 is the ASCII code for new line
len: equ $ - errMsg; Length of the message errmsg is put in variable len
;
section :text
  global _start
    _start:
;

;
    _openfile:
    mov eax, 5; "Open the file" function is called
    mov ebx, filename; Move file name in the register ebx
    mov ecx, 0; No option is given
    int 0x80; Services register 0x80 is called
    mov sf, 0; Check if the file was properly opened
;
    _cantopen:
    mov edx, len; The length of the message to show is given as third argument
    mov ecx, errMsg; The error message is given as second argument to be written in output
    mov ebx, 1; The output device is given as first argument, in this case the screen (code 1)
    int 0x80; Services register 0x80 is called
    jmp exit
;
    _exit:
      mov eax 1; "Close the program" function is called
      mov ebx 0; Move 1 to the register ebx to properly close the program
      int 0x80; Services register 0x80 is called