School Commit Init

2024-08-31 12:07:21 +03:00
commit 0b130ee18c
2801 changed files with 4720552 additions and 0 deletions
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+bits 32 ; assembling for the 32 bits architecture
+
+; declare the EntryPoint (a label defining the very first instruction of the program)
+global start        
+
+; declare external functions needed by our program
+extern exit,fopen,fprintf,fscanf,fread,fwrite,remove,rename,fclose
+import exit msvcrt.dll  ; exit is a function that terminates the program. It is defined in msvcrt.dll
+import fopen msvcrt.dll   ; fopen is a function that opens a file. It is defined in msvcrt.dll
+import fprintf msvcrt.dll ; fprintf is a function that prints a formatted string to a file. It is defined in msvcrt.dll
+import fscanf msvcrt.dll  ; fscanf is a function that reads a formatted string from a file. It is defined in msvcrt.dll
+import fread msvcrt.dll   ; fread is a function that reads a block of data from a file. It is defined in msvcrt.dll
+import fwrite msvcrt.dll  ; fwrite is a function that writes a block of data to a file. It is defined in msvcrt.dll
+import remove msvcrt.dll  ; remove is a function that deletes a file. It is defined in msvcrt.dll
+import rename msvcrt.dll  ; rename is a function that renames a file. It is defined in msvcrt.dll
+import fclose msvcrt.dll  ; fclose is a function that closes a file. It is defined in msvcrt.dll
+
+
+; our data is declared here (the variables needed by our program)
+segment data use32 class=data
+    ; ...
+    file_path_read db "a.txt", 0 ; the path to the file we want to open
+    file_path_write db "b.txt", 0 ; the path to the file we want to open
+    access_mode_read db "r", 0       ; the access mode we want to use when opening the file
+    access_mode_write db "w", 0      ; the access mode we want to use when opening the file
+    file_read dd 0 ; the file pointer returned by fopen
+    file_write dd 0 ; the file pointer returned by fopen
+    read_value dd 0 ; the value read from the file
+
+; our code starts here
+segment code use32 class=code
+    start:
+        ; ...
+        ; open the file
+        push    dword access_mode_read ; push the parameter for fopen onto the stack
+        push    dword file_path_read ; push the parameter for fopen onto the stack
+        call   [fopen]         ; call fopen to open the file
+        add    esp, 4*2         ; remove the parameters from the stack
+        cmp     eax, 0         ; compare the return value of fopen with 0
+        jz     exit_label           ; if fopen returned 0, then the file could not be opened, so we exit_label the program
+        mov     [file_read], eax    ; save the file pointer returned by fopen in the variable file
+        
+        push   dword access_mode_write ; push the parameter for fopen onto the stack
+        push   dword file_path_write ; push the parameter for fopen onto the stack
+        call   [fopen]         ; call fopen to open the file
+        add    esp, 4*2         ; remove the parameters from the stack
+        cmp     eax, 0         ; compare the return value of fopen with 0
+        jz     exit_label           ; if fopen returned 0, then the file could not be opened, so we exit_label the program
+        mov     [file_write], eax    ; save the file pointer returned by fopen in the variable file
+
+        ; read the file
+        loop_label:
+
+        push    dword [file_read] ; push the parameter for fread onto the stack
+        push    dword 1      ; push the parameter for fread onto the stack
+        push    dword 1      ; push the parameter for fread onto the stack
+        push    dword read_value ; push the parameter for fread onto the stack
+        call   [fread]         ; call fread to read the file
+        add    esp, 4*4         ; remove the parameters from the stack
+        cmp    eax, 0         ; compare the return value of fread with 0
+        jz     end           ; if fread returned 0, then the file could not be read, so we exit_label the program
+
+        inc byte [read_value] ; increment the value read from the file
+
+        push    dword [file_write] ; push the parameter for fwrite onto the stack
+        push    dword 1      ; push the parameter for fwrite onto the stack
+        push    dword 1      ; push the parameter for fwrite onto the stack
+        push    dword read_value ; push the parameter for fwrite onto the stack
+        call   [fwrite]         ; call fwrite to write the file
+        add   esp, 4*4         ; remove the parameters from the stack
+        cmp    eax, 0         ; compare the return value of fwrite with 0
+        jz     exit_label           ; if fwrite returned 0, then the file could not be written, so we exit_label the program
+        jmp loop_label
+
+        end:
+
+        ; close the file
+        push    dword [file_read] ; push the parameter for fclose onto the stack
+        call   [fclose]         ; call fclose to close the file
+        add    esp, 4         ; remove the parameter from the stack
+        push    dword [file_write] ; push the parameter for fclose onto the stack
+        call   [fclose]         ; call fclose to close the file
+        add    esp, 4         ; remove the parameter from the stack
+
+        ;remove a.txt file
+        push    dword file_path_read ; push the parameter for remove onto the stack
+        call   [remove]         ; call remove to remove the file
+        add    esp, 4         ; remove the parameter from the stack
+
+
+        ;rename b.txt to a.txt
+        push    dword file_path_read ; push the parameter for rename onto the stack
+        push    dword file_path_write ; push the parameter for rename onto the stack
+        call   [rename]         ; call rename to rename the file
+        add    esp, 4*2         ; remove the parameters from the stack
+
+
+        exit_label:
+        push    dword 0      ; push the parameter for exit_label onto the stack
+        call    [exit]       ; call exit_label to terminate the program