; sped - the stupidly pointless editor
; written by pinosaur
+%include "fileutils.S"
+
global main
extern printf
+extern fflush
+extern stdout
; macros
%macro write_str 2
section .data
banner_str db `SPED - the stupidly pointless editor\n`, 0x00
- readfile_str db `reading file %s\n`, 0x00
nofile_str db `no file provided\n`, 0x00
- argcount_str db `there are %d args\n`, 0x00
- wrongfile_str db `unable to open file, error code: %i\n`, 0x00
- char_str db `read this char: %i\n`, 0x00
- printfint_str db `int: %i\n`, 0x00
+ prompt_str db `sped > `, 0x00
+ invalidcommand_str db `invalid command\n`, 0x00
+ charcount_str db `read %i chars\n`, 0x00
section .bss
- read_buf resb 64
+ buffer resb 4
+ buffer_lines resb 4
+ cur_line resb 4
section .text
main:
_main_existing:
mov ebx, DWORD [ebp+_ARGV]
- add ebx, 4
+ add ebx, 4 ; first user arg is filename
push DWORD [ebx]
- ; push readfile_str
- ; call printf
-
call readFile
+ mov [buffer], eax
+ mov [buffer_lines], ebx
+ mov DWORD [cur_line], 0x00
+
+ call repl
+
mov eax, 0
jmp _main_exit
pop ebp
ret
+; prompt for user
+; no args - reads from globals
+repl:
-; reads file line by line
-; args: filename
-; return:
-; eax - pointer to mem
-; ecx - lines read
-readFile:
- %define _FILE_NAME 8
- %define FILE_HANDLE 4
+ %define CMDSTR 4 ; the previous line read from user
push ebp
mov ebp, esp
-
- ; allocate vars
- sub esp, 4
- mov DWORD [ebp-FILE_HANDLE], 0x00
- ; open existing file
- mov eax, 5
- mov ebx, [ebp+_FILE_NAME]
- mov ecx, 0
- mov edx, 0777
- int 0x80
- mov [ebp-FILE_HANDLE], eax
+ sub esp, 4
- ; check if file was open successfully
- cmp eax, 0
- jge _readFile_noerror
- push eax
- push wrongfile_str
+ _repl_loop:
+
+ ; print the prompt
+ push prompt_str
call printf
- jmp _readFile_exit
+ push DWORD [stdout]
+ call fflush
- _readFile_noerror:
- push DWORD [ebp-FILE_HANDLE]
- call readLine
+ ; read line from stdin
+ push 0
+ call readLine
- jmp _readFile_exit
+ mov DWORD [ebp-CMDSTR], eax
- _readFile_exit:
- ; close file
- mov eax, 6
- mov ebx, [ebp-FILE_HANDLE]
- int 0x80
+ ; commands are single char for now
+ cmp ecx, 1
+ jne _repl_invalid
- %undef _FILE_NAME
- %undef FILE_HANDLE
-
- mov esp, ebp
- pop ebp
- ret
+ ; parse commands
+ mov eax, DWORD [ebp-CMDSTR]
+ mov eax, [eax]
+ ; q exists program
+ mov eax, DWORD [ebp-CMDSTR]
+ cmp BYTE [eax], 'q'
+ jne _repl_cmd_quit_end
+ jmp _repl_exit
+ _repl_cmd_quit_end:
-; reads a line until newline character is reached
-; args: file_handle
-; return:
-; location to buffer
-; contains eof
-readLine:
- %define _FILE_HANDLE 8
- %define CHAR_PTR 4
- push ebp
- mov ebp, esp
-
- sub esp, 4
- mov DWORD [ebp-CHAR_PTR], 0x00
-
- _readLine_loop:
- ; if buffer is full
- cmp BYTE [ebp-CHAR_PTR], 64
- jne _readLine_notfull
- jmp _readLine_exit
-
- _readLine_notfull:
- ; read a single character
- mov eax, 3
- mov ebx, [ebp+_FILE_HANDLE]
- mov ecx, read_buf
- add ecx, [ebp-CHAR_PTR]
- mov edx, 1
- int 0x80
-
- mov eax, 4
- mov ebx, 1
- mov ecx, read_buf
- add ecx, [ebp-CHAR_PTR]
- mov edx, 1
- int 0x80
+ _repl_invalid:
+ push invalidcommand_str
+ call printf
- ; check for newline
- mov eax, read_buf
- add eax, [ebp-CHAR_PTR]
- cmp DWORD [eax], 0x0a
- je _readLine_exit
+ _repl_continue:
+ jmp _repl_loop
- ; 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
-
- jmp _readLine_loop
+ _repl_exit:
- _readLine_exit:
-
- %undef _FILE_HANDLE
- %undef CHAR_PTR
+ %undef CMDSTR
mov esp, ebp
pop ebp
ret
-
+
