From: Daniel Liu <mr.picklepinosaur@gmail.com>
Date: Sun, 20 Jun 2021 02:00:27 +0000 (-0400)
Subject: appending lines after
X-Git-Url: https://git.danieliu.xyz/?p=sped.git;a=commitdiff_plain;h=0e7c787c5d6e31bd64fb9348c1cc4704d5b5928e

appending lines after
---

diff --git a/fileutils.asm b/fileutils.asm
index 6c30ca6..54c9895 100644
--- a/fileutils.asm
+++ b/fileutils.asm
@@ -14,6 +14,7 @@ global writeFile
 
 section .data
     wrongfile_str db `unable to open file, error code: %i\n`, 0x00
+    returnvalue_str db `system call return was %i\n`, 0x00
 
 section .text
 
@@ -62,13 +63,13 @@ readFile:
 
     push DWORD [ebp-FILE_HANDLE]
     call readLine 
-
     mov esi, eax
     mov [ebp-IS_EOF], ebx
 
     ; check if eof was reached
     cmp DWORD [ebp-IS_EOF], 1
     je _readFile_exit
+
     
     ; push esi
     ; call printf
@@ -233,11 +234,13 @@ writeFile:
 
     ; check if file was open successfully
     cmp eax, 0
-    jge _writeFile_loop
-    push eax
-    push wrongfile_str
-    call printf
-    jmp _writeFile_exit
+    jl _writeFile_error
+
+    ; truncate file
+    mov eax, 93
+    mov ebx, [ebp-FILE_HANDLE]
+    mov ecx, 1
+    int 0x80
     
     _writeFile_loop:
 
@@ -262,6 +265,12 @@ writeFile:
 
     jmp _writeFile_loop
 
+    _writeFile_error:
+    push eax
+    push wrongfile_str
+    call printf
+    jmp _writeFile_exit
+
     _writeFile_exit:
 
     ; close file
diff --git a/repl.asm b/repl.asm
index 738da94..6a1472f 100644
--- a/repl.asm
+++ b/repl.asm
@@ -201,12 +201,42 @@ repl:
     push DWORD [buffer_lines]
     push DWORD [cur_line]
     call shiftLeft
+    mov [buffer], eax
 
     sub DWORD [buffer_lines], 1
 
     jmp _repl_continue
     _repl_cmd_delete_end:
 
+    ; o appends text after line =-=-=-=-=-=-=-=-=
+    mov eax, DWORD [ebp-CMDSTR]
+    cmp BYTE [eax], 'o'
+    jne _repl_cmd_appendup_end
+
+    ; make room first
+    push DWORD [buffer]
+    push DWORD [buffer_lines]
+    push DWORD [cur_line]
+    call shiftRight
+    mov [buffer], eax
+
+    ; input text
+    push 0
+    call readLine
+    mov esi, eax
+
+    ; insert new string
+    mov eax, [cur_line]
+    mov ecx, 4
+    mul ecx
+    add eax, DWORD [buffer]
+    mov [eax], esi
+
+    add DWORD [buffer_lines], 1
+
+    jmp _repl_continue
+    _repl_cmd_appendup_end:
+
     ; w writes file =-=-=-=-=-=-=-=-=-=-=-=-=
     mov eax, DWORD [ebp-CMDSTR]
     cmp BYTE [eax], 'w'
diff --git a/utils.asm b/utils.asm
index 9feb498..441efc1 100644
--- a/utils.asm
+++ b/utils.asm
@@ -55,10 +55,20 @@ shiftLeft:
     call memmove
     
     ; realloc to shrink the array
+    mov eax, DWORD [ebp+_BUFFER_LEN]
+    sub eax, 1 
+    mov ecx, 4
+    mul ecx
+    push eax
+    push DWORD [ebp+_BUFFER]
+    call realloc
+    mov [ebp-NEW_BUFFER], eax
 
     %undef _BUFFER
     %undef _BUFFER_LEN
     %undef _SHIFT_POS
+
+    mov eax, [ebp-NEW_BUFFER]
     
     mov esp, ebp
     pop ebp
@@ -66,12 +76,55 @@ shiftLeft:
 
 ; grows array by shifting blocks right
 ; args: buffer, buffer_len, shift_pos (new uninitalized index)
-; return: location of new buffer
+; return:
+;   eax: location of new buffer
 shiftRight:
+    %define _BUFFER      16
+    %define _BUFFER_LEN  12
+    %define _SHIFT_POS   8
+    %define SHIFT_LEN    4
+    %define BLOCK_OFFSET 8 ; mem location of block to be destroyed
+    %define NEW_BUFFER   12
+
     push ebp
     mov ebp, esp
 
-    
+    sub esp, 12
+
+    ; realloc to make memory bigger first
+    mov eax, DWORD [ebp+_BUFFER_LEN]
+    add eax, 1
+    mov ecx, 4
+    mul ecx
+    push eax
+    push DWORD [ebp+_BUFFER]
+    call realloc
+    mov [ebp-NEW_BUFFER], eax
+
+    ; set vars
+    mov eax, DWORD [ebp+_BUFFER_LEN]
+    sub eax, [ebp+_SHIFT_POS]
+    mov [ebp-SHIFT_LEN], eax
+
+    str_offset [ebp-NEW_BUFFER], [ebp+_SHIFT_POS]
+    mov [ebp-BLOCK_OFFSET], eax
+
+    ; move the memory
+    mov eax, DWORD [ebp-SHIFT_LEN]
+    mov ecx, 4
+    mul ecx
+    push eax
+    push DWORD [ebp-BLOCK_OFFSET]
+    mov eax, DWORD [ebp-BLOCK_OFFSET]
+    add eax, 4
+    push eax
+    call memmove
+
+    %undef _BUFFER
+    %undef _BUFFER_LEN
+    %undef _SHIFT_POS
+
+    mov eax, [ebp-NEW_BUFFER]
     
     mov esp, ebp
     pop ebp