From 2505d1841221648a72e768f23a5a475c8e1c01d1 Mon Sep 17 00:00:00 2001
From: Daniel Liu <mr.picklepinosaur@gmail.com>
Date: Sat, 19 Jun 2021 16:16:14 -0400
Subject: [PATCH] lots more commands

---
 fileutils.asm |  8 +++--
 sped.asm      | 86 ++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 87 insertions(+), 7 deletions(-)

diff --git a/fileutils.asm b/fileutils.asm
index 0f829f5..ad284b5 100644
--- a/fileutils.asm
+++ b/fileutils.asm
@@ -80,10 +80,14 @@ readFile:
     mov DWORD [ebp-BUF_PTR], eax
 
     ; write string to buffer
-    mov eax, DWORD [ebp-BUF_PTR]
+    mov eax, [ebp-LINES_READ]
     mov ecx, 4
     mul ecx
-    mov eax, esi
+    add eax, DWORD [ebp-BUF_PTR]
+    mov [eax], esi
+
+    ; push DWORD [eax]
+    ; call printf
 
     add DWORD [ebp-LINES_READ], 1
 
diff --git a/sped.asm b/sped.asm
index 1e20038..585697b 100644
--- a/sped.asm
+++ b/sped.asm
@@ -20,9 +20,13 @@ 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
@@ -55,9 +59,13 @@ 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
@@ -98,7 +106,7 @@ repl:
 
     ; commands are single char for now
     cmp ecx, 1 
-    jne _repl_invalid
+    jne _repl_invalid_cmd
 
     ; parse commands
     mov eax, DWORD [ebp-CMDSTR]
@@ -111,10 +119,78 @@ repl:
     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:
+
+
+    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
-- 
2.20.1