c - Trouble with converting string to integer using ATOI In Assembly -

i'm trying read in 2 strings, convert them numbers using atoi function, , print out result.

here's uninitialized variables. (%define buflen 20)

section .bss                    ; uninitialized data section  m:           resb buflen             ;string 1 mlen:        resb 4 r:           resb buflen             ;string 2 rlen:        resb 4 

here's user input/ attempt allocate memory

   ; prompt user first number      mov     eax, syscall_write      ; write function     mov     ebx, stdout             ; arg1: file descriptor     mov     ecx, msg1               ; arg2: addr of message     mov     edx, len1               ; arg3: length of message     int     080h                    ; ask kernel write       ; read in user input     ;     mov     eax, syscall_read       ; read function     mov     ebx, stdin              ; arg 1: file descriptor     mov     ecx, m                  ; arg 2: address of buffer     mov     edx, buflen                  ; arg 3: buffer length     int     080h     mov     [rlen], eax             ; save length of string read      ; prompt user second number      mov     eax, syscall_write      ; write function     mov     ebx, stdout             ; arg1: file descriptor     mov     ecx, msg2               ; arg2: addr of message     mov     edx, len2               ; arg3: length of message     int     080h                    ; ask kernel write      ; read in user input     mov     eax, syscall_read       ; read function     mov     ebx, stdin              ; source     mov     ecx, r                  ; destination     mov     edx, buflen                  ; length of destination     int     080h                   mov     [mlen], eax             ; save length of string read 

now i'm trying convert strings using atoi , print them out

    ;convert #     mov     eax, 0                  ;zero out register     mov     eax, m     call    atoi     add     esp, 4      ;print     push    ax     push    print_r     call    printf     add     esp, 8      ;convert #     mov     eax, 0                  ;zero out register     mov     eax, r     call    atoi     add     esp, 4      ;print     push    ax     push    print_r     call    printf     add     esp, 8 

this output...

enter first #: 1234

enter second#: 1234

number: 1234

hanging on second atoi call

for start, you're not allocating enough space input and you're not reading properly.

if input string 12345678, need 8 bytes characters, 1 newline, , 1 terminating \0. so, resd 1 not going cut mustard, gives 8 bytes rather ten.

for reading information:

mov     eax, syscall_read       ; read function mov     ebx, stdin              ; arg 1: file descriptor mov     ecx, m                  ; arg 2: address of buffer mov     edx, 1                  ; arg 3: buffer length int     080h 

edx meant number of bytes read , have set 1 reason. that's not going entire number, rather first character of first number.

on top of input problems, there's couple of problems there well.

first, statement: mov eax, [m] gets contents of memory @ m. if you're calling atoi, want address itself.

secondly, need examine calling convention. adding of values esp seems ... unusual me. may correct doesn't seem match calling convention i've ever seen.