global main
extern printf
+extern malloc
+extern realloc
+extern free
+extern memset
; macros
%macro write_str 2
char_str db `read this char: %i\n`, 0x00
printfint_str db `int: %i\n`, 0x00
-section .bss
- read_buf resb 64
-
section .text
main:
%define _ARGC 8
; eax - pointer to mem
; ecx - lines read
readFile:
- %define _FILE_NAME 8
+ %define _FILE_NAME 8
%define FILE_HANDLE 4
+ %define IS_EOF 8
+ %define LINES_READ 12
+ %define BUF_PTR 16 ; malloced array of strings
push ebp
mov ebp, esp
; allocate vars
- sub esp, 4
+ sub esp, 16
mov DWORD [ebp-FILE_HANDLE], 0x00
+ mov DWORD [ebp-IS_EOF], 0x00
+ mov DWORD [ebp-LINES_READ], 0x00
+
+ push 0
+ call malloc
+ mov [ebp-BUF_PTR], eax
; open existing file
mov eax, 5
; check if file was open successfully
cmp eax, 0
- jge _readFile_noerror
+ jge _readFile_loop
push eax
push wrongfile_str
call printf
jmp _readFile_exit
- _readFile_noerror:
+ _readFile_loop:
+
+ ; check if eof was reached
+ cmp DWORD [ebp-IS_EOF], 1
+ je _readFile_exit
+
push DWORD [ebp-FILE_HANDLE]
call readLine
- jmp _readFile_exit
+ mov esi, eax
+ mov [ebp-IS_EOF], ebx
+
+ push esi
+ call printf
+
+ ; make string buffer bigger
+ mov eax, DWORD [ebp-LINES_READ]
+ add eax, 1
+ mov ecx, 4
+ mul ecx
+ push eax
+ push DWORD [ebp-BUF_PTR]
+ call realloc
+ mov DWORD [ebp-BUF_PTR], eax
+
+ ; write string to buffer
+ mov eax, DWORD [ebp-BUF_PTR]
+ mov ecx, 4
+ mul ecx
+ mov eax, esi
+
+ add DWORD [ebp-LINES_READ], 1
+
+ jmp _readFile_loop
_readFile_exit:
; close file
%undef _FILE_NAME
%undef FILE_HANDLE
+ %undef IS_EOF
+ %undef LINES_READ
+ %undef BUF_PTR
mov esp, ebp
pop ebp
; reads a line until newline character is reached
; args: file_handle
; return:
-; location to buffer
-; contains eof
+; eax: location to buffer
+; ebx: contains eof
readLine:
%define _FILE_HANDLE 8
- %define CHAR_PTR 4
+ %define CHAR_COUNT 4 ; count number of characters read
+ %define BLOCK_COUNT 8 ; number of 64 blocks we've read
+ %define STR_PTR 12 ; malloced buffer to store read string
push ebp
mov ebp, esp
+
+ ; allocate vars
+ sub esp, 12
+ mov DWORD [ebp-CHAR_COUNT], 0x00
+ mov DWORD [ebp-BLOCK_COUNT], 0x00
+
+ push 64
+ call malloc
+ mov [ebp-STR_PTR], eax
- sub esp, 4
- mov DWORD [ebp-CHAR_PTR], 0x00
+ push DWORD [ebp-STR_PTR]
+ push 0x00
+ push 64
_readLine_loop:
; if buffer is full
- cmp BYTE [ebp-CHAR_PTR], 64
+ cmp BYTE [ebp-CHAR_COUNT], 63 ; leave one byte for null byte
jne _readLine_notfull
jmp _readLine_exit
; read a single character
mov eax, 3
mov ebx, [ebp+_FILE_HANDLE]
- mov ecx, read_buf
- add ecx, [ebp-CHAR_PTR]
+ mov ecx, [ebp-STR_PTR]
+ add ecx, [ebp-CHAR_COUNT]
mov edx, 1
int 0x80
- mov eax, 4
+ ; mov eax, 4
+ ; mov ebx, 1
+ ; mov ecx, [ebp-STR_PTR]
+ ; add ecx, [ebp-CHAR_COUNT]
+ ; mov edx, 1
+ ; int 0x80
+
+ ; check for eof
+ cmp eax, 0 ; eax has zero on eof
+ jne _readLine_not_eof
mov ebx, 1
- mov ecx, read_buf
- add ecx, [ebp-CHAR_PTR]
- mov edx, 1
- int 0x80
+ jmp _readLine_exit
+ _readLine_not_eof:
; check for newline
- mov eax, read_buf
- add eax, [ebp-CHAR_PTR]
+ mov eax, [ebp-STR_PTR]
+ add eax, [ebp-CHAR_COUNT]
cmp DWORD [eax], 0x0a
- je _readLine_exit
-
- ; check for eof
- mov eax, read_buf
- add eax, [ebp-CHAR_PTR]
- cmp DWORD [eax], 0x05
- je _readLine_exit
-
- add DWORD [ebp-CHAR_PTR], 1
+ jne _readLine_not_newline
+ mov ebx, 0
+ jmp _readLine_exit
+ _readLine_not_newline:
+ add DWORD [ebp-CHAR_COUNT], 1
jmp _readLine_loop
_readLine_exit:
+ mov eax, DWORD [ebp-STR_PTR]
+
%undef _FILE_HANDLE
- %undef CHAR_PTR
+ %undef CHAR_COUNT
+ %undef BLOCK_COUNT
+ %undef STR_PTR
mov esp, ebp
pop ebp
