X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=sped.asm;h=d7dcb8de8a7a55ed4bddc4917be6192cc886f130;hb=aab6303fb9c43a2d727774c25b3c50a4b1fcae8d;hp=1e200387d1f3d269662b89ce5a589cb7246a8e57;hpb=0af29f26ae69ba0ba9c5088612f0c537a20c0344;p=sped.git diff --git a/sped.asm b/sped.asm index 1e20038..d7dcb8d 100644 --- a/sped.asm +++ b/sped.asm @@ -3,10 +3,12 @@ %include "fileutils.S" -global main extern printf extern fflush extern stdout +extern free + +global main ; macros %macro write_str 2 @@ -20,9 +22,13 @@ extern stdout section .data banner_str db `SPED - the stupidly pointless editor\n`, 0x00 nofile_str db `no file provided\n`, 0x00 + readlines_str db `opened file with %i lines\n`, 0x00 prompt_str db `sped > `, 0x00 - invalidcommand_str db `invalid command\n`, 0x00 + invalidcmd_str db `invalid command\n`, 0x00 + invalidaddr_str db `invalid address\n`, 0x00 charcount_str db `read %i chars\n`, 0x00 + currentline_str db `current line: %i\n`, 0x00 + echo_str db `%s`, 0x00 ; print strings without format exploit section .bss buffer resb 4 @@ -55,15 +61,23 @@ main: call readFile mov [buffer], eax - mov [buffer_lines], ebx + mov [buffer_lines], ecx mov DWORD [cur_line], 0x00 + push DWORD [buffer_lines] + push readlines_str + call printf + call repl mov eax, 0 jmp _main_exit _main_exit: + + ; free string array + + %undef _ARGC %undef _ARGV @@ -98,23 +112,142 @@ repl: ; commands are single char for now cmp ecx, 1 - jne _repl_invalid + jne _repl_invalid_cmd ; parse commands mov eax, DWORD [ebp-CMDSTR] mov eax, [eax] - ; q exists program + ; q exists program =-=-=-=-=-=-=-=-=-=-=-=-= mov eax, DWORD [ebp-CMDSTR] cmp BYTE [eax], 'q' jne _repl_cmd_quit_end jmp _repl_exit _repl_cmd_quit_end: + ; p prints current line =-=-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], 'p' + jne _repl_cmd_print_end + + mov eax, DWORD [cur_line] + mov ecx, 4 + mul ecx + add eax, [buffer] + push DWORD [eax] + push echo_str + call printf + jmp _repl_continue + _repl_cmd_print_end: + + ; n prints the current line number =-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], 'n' + jne _repl_cmd_number_end + + push DWORD [cur_line] + push currentline_str + call printf + + jmp _repl_continue + _repl_cmd_number_end: + + ; - goes to prev line =-=-=-=-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], '-' + jne _repl_cmd_decline_end + + ; make sure we are within bounds + mov eax, DWORD [cur_line] + sub eax, 1 + cmp eax, 0 + jl _repl_invalid_addr + + sub DWORD [cur_line], 1 + + jmp _repl_continue + _repl_cmd_decline_end: + + ; + goes to next line =-=-=-=-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], '+' + jne _repl_cmd_incline_end + + ; make sure we are within bounds + mov eax, DWORD [cur_line] + add eax, 1 + cmp eax, [buffer_lines] + jge _repl_invalid_addr + + add DWORD [cur_line], 1 + + jmp _repl_continue + _repl_cmd_incline_end: + + ; g goes to first line =-=-=-=-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], 'g' + jne _repl_cmd_jumptop_end + + mov DWORD [cur_line], 0x00 + + jmp _repl_continue + _repl_cmd_jumptop_end: + + ; G goes to last line =-=-=-=-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], 'G' + jne _repl_cmd_jumpbot_end + + mov eax, DWORD [buffer_lines] + sub eax, 1 + mov DWORD [cur_line], eax + + jmp _repl_continue + _repl_cmd_jumpbot_end: + + ; c changes the current line =-=-=-=-=-=-=-=-=-= + mov eax, DWORD [ebp-CMDSTR] + cmp BYTE [eax], 'c' + jne _repl_cmd_change_end + + ; read a new line to use + push 0 + call readLine + + mov esi, eax + + ; free old string + mov eax, [cur_line] + mov ecx, 4 + mul ecx + add eax, [buffer] + push DWORD [eax] + call free + + ; insert new string + mov eax, [cur_line] + mov ecx, 4 + mul ecx + add eax, DWORD [buffer] + mov [eax], esi + + jmp _repl_continue + _repl_cmd_change_end: + + + jmp _repl_invalid_cmd + + ; some error messages + _repl_invalid_cmd: + push invalidcmd_str + call printf + jmp _repl_continue - _repl_invalid: - push invalidcommand_str + _repl_invalid_addr: + push invalidaddr_str call printf + jmp _repl_continue _repl_continue: jmp _repl_loop