C_REMINDER.txt

****C PROGRAMMING****

[Compiler/IDE]
* codeblocks
* dev c++
* turbo c++
* netbeans

[Program Sections]
* Documentation/Comment
* Link
* Global Declaration
* Main()
* Subprogram

[Program Stages]
* Preprocessing (Source Code)
* Compilation (Temporary Intermediate File)
* Assembling (Object File)
* Linking (Executable File)
* Loading

[Keywords]
auto, break, case, char, const, continue, default, do, double, else, enum, extern, float, for, goto, if, int, long, register, return, short, signed, sizeof, static, struct, switch, typedef, union, unsigned, void, volatile, while

[Declaring Variable]
* data_type variable_name
* starts with letter/underscore
* no special symbols/spaces/keywords
* int a = 2;

[Data Types]
* Primary (char, int, float, double)
* Specifiers (unsigned, long, short)
* Secondary (array, function, structure, union, enumeration, pointer)
* User-Defined

[Instruction Types]
* Type Declaration
* Arithmetic
* Control (Sequence, Decision, Loop, Case)

[Operators]
* Arithmetic
   - Addition/Unary Plus (+)
   - Subtraction/Unary Minus (-)
   - Multiplication (*)
   - Division (/)
   - Modulus (%)
   - Increment (++)
   - Decrement (--)
* Relational
   - Equal (==)
   - Greater Than (>)
   - Less Than (<)
   - Greater Than or Equal (>=)
   - Less Than or Equal (<=)
   - Not Equal (!=)
* Logical
   - And (&&)
   - Or (||)
   - Not (!)
* Assignment
   - Assignment (=)
   - Pluse Equal To (+=)
   - Minus Equal To (-=)
   - Multiply by Equal To (*=)
   - Divide by Equal To (/=)
   - Modulus by Equal To (%=)
* Conditional
   - Ternary (expression?if_true:if_false)
* Bitwise
   - And (&)
   - Or (|)
   - Exclusive Or (^)
   - One’s Complement (~)
   - Left Shift (<<)
   - Right Shift (>>)
* Special
   - Size (sizeof())
   - Address (&)
   - Pointer (*)
   - Function Call (())
   - Array Element ([])

[Escape Sequence Characters]
* New Line (\n)
* Back Slash (\b)
* Tab (\t)
* Carriage Return (\r)
* Alert (\a)
* Single Quote (\’)
* Double Quote (\”)
* Back Slash (\\)
* Null (\0)
* Alert (\a)
* Form Feed (\f)
* Vertical Tab (\v)
* Question Mark (\?)
* Hexadecimal (\x)
* Octal (\o, \n)

[Flow Chart Components]
* Start/Stop
* Input/Output
* Decision Making
* Process
* Predefined Process
* Looping
* Connector
* Flow Direction

[Decision Making]
* if-else
* switch-case-default-break
* ternary operator (?:)

[Loop]
* while
* do-while
* for

[Jump]
* break
* continue
* goto

[Array Declaration]
data_type variable_name[size];

[Console Functions]
printf, scanf, clrscr, getch, gotoxy, ...

[String Formatters]
* %d: decimal
* %u: unsigned
* %c: character
* %s: string

[Pointer Declaration]
data_type *variable_name;
p: address
*p: value
**pp: pointer-to-pointer, address of pointer
p++: increment address by size of dataype

[Function]
* Library/User-Defined Function
* Function Declaration: return_type function_name(parameters)
* Function Definition
* Function Call

[Structure]
* struct structure_name
* structure padding (#pragma pack(1))
* structure nesting
* structure array

[Union]
* union union_name
* size = member with largest size
* no direct initialization
* store only value of one member at a time

[String Functions]
strlen, strcpy, strcat, strrev, strcmp, strupr, strlwr, puts, gets

[File Handling]
* Functions
   - Create
   - Open
   - Read
   - Write
   - Close
* Modes
   - Read(r): open existing
   - Write(w): delete existing and create new
   - Append(a): open existing or create new
   - Read-Write(r+): open existing
   - Read-Write(w+): create new
   - Read-Append(a+): open existing
   - Binary Write (wb+)
   - Binary Read (rb)
* fopen, fclose, fgetc, fputc, fprintf, fscanf, fread, fwrite, ...
* fflush(stdin): Clear Standard Input Buffer
* End of File (EOF)

[Library File]
* Compile Source Code (test.c)
* Generate OBJ File (test.obj)
* tlib stdio.lib + c:\ test.obj (Add to Existing Library)
* tlib stdio.lib - c:\ test.obj (Delete from Existing Library)
* Header File Prototype (test.h)
* Options: Applications: Library (test.lib)

[Function Call]
* By Value (Value)
* By Reference (Address)

[Pointer to Function]
* data_type (*pointer_name)();

[Pointer to Structure]
* struct struct_name *p; (Struct Pointer Declaration)
* p=&s (Address Assignment)
* p->name (Member Access)
* (*p).name (Member Access)

[Preprocessor Directives]
* #include <file_name> (Header File)
* #define (Macro Expansion)
* #if, #elif, #else, #endif, #ifdef, #ifndef, #undif (Conditional Compilation)
* #pragma
   - startup function() (Execution Before Main)
   - exit function() (Execution After Main)
   - warn -rvl (Function Return Value)
   - warn -par (Function Parameters)
   - warn -rch (Reachable Code)

[Command Line Arguments]
* int argc (Number of Arguments)
* char *argv[] (Argument Array)

[Dynamic Memory Allocation]
* Memory Segmentation 
   - Stack Segment (Local/Auto Variables/Functions)
   - Heap Segment (Dynamic Memory Allocation)
   - Data Segment (Global/Static Variables)
   - Code Segment (All Instructions)
* stdlib.h (Header File)
* Functions: malloc, calloc, realloc, free
* data_type *ptr = (*data_type) malloc(byte_size)
* realloc(ptr, new_size)

[Storage Classes]
* Automatic (auto): Stack Memory, Garbage Initialization, Local Scope, In-Block Lifetime
* Register: CPU Register, Garbage Initialization, Local Scope, In-Block Lifetime, Fastest
* Static: Code Memory, Zero Initialization, Local Scope, Value Persistence
* Extern: Code Memory, Zero Initialization, Global Scope, Program Lifetime
* extern (Initialization Required for Global Variable)

[Memory Models]
* Memory Segment: 16 x 64kB (1024kB = 1MB)
   - 15: ROM
   - 14: BIOS
   - 11: TEXT VIDEO
   - 10: GRAPHICS VIDEO
   - 8: DATA SEGMENT (0x0000 - 0xFFFF)
       * CODE (16kB)
       * DATA (16kB)
       * HEAP (16kB)
       * STACK (16kB)
* Near Pointer: Data Segment (16kB)
* Far Pointer: Memory Segment (1MB), Segment:Offset
* Tiny: CS Near:DS Near
* Small: CS Near:DS Near
* Medium: CS Far:DS Near
* Compact: CS Near:DS Far
* Large: CS Far:DS Far
* Huge: CS Far:DS Far

[Toggle Keys]
* 0x417 (On/Off Status)
   - 0: RIGHT-SHIFT
   - 1: LEFT-SHIFT
   - 2: CTRL
   - 3: ALT
   - 4: SCROLL-LOCK
   - 5: NUM-LOCK
   - 6: CAPS-LOCK
   - 7: INSERT
* 0x418 (Pressed/Released Status)
   - 0: RIGHT-ALT
   - 1: LEFT-ALT
   - 2: SYSTEM-REQ
   - 3: HOLD-STATE
   - 4: SCROLL-LOCK
   - 5: NUM-LOCK
   - 6: CAPS-LOCK
   - 7: INSERT

[Registers]
* General Purpose Registers (16-Bit)
   - AX (AL + AH)
   - BX (BL + BH)
   - CX (CL + CH)
   - DX (DL + DH)
* Segment Registers (16-Bit)
   - CS (Code Segment)
   - DS (Data Segment)
   - ES (Extra Segment)
   - SS (Stack Segment)
* Offset Registers (16-Bit)
   - IP (Instruction Pointer)
   - SP (Stack Pointer)
   - BP (Base Pointer)
   - SI (Source Index)
   - DI (Destination Index)
* Flag Register (16-Bit)
* int86() (dos.h)
   - interrupt number
   - input register
   - output register
* union REGS
   - struct WORDREGS x
       * unsigned int ax, bx, cx, dx
       * unsigned int si, di, cflag, flags
   - stuct BYTEREGS h
       * unsigned char al, ah, bl, bh
       * unsigned char cl, ch, dl, dh

[BIOS Functions]
* Interrupt Vector Table (IVT)
   - 0-255
   - getvect (Get Address of ISR)
   - setvect (Set Address of User Defined Interrupt Handler)
   - keep (Reserve Memory after Program Termination)
* Mouse
   - Interrupt: 0x33
   - Initialize Mouse: AX = 0 (Success: fff, Fail: 0)
   - Show Pointer: AX = 1
   - Hide Pointer: AX = 2
   - Button Status: AX = 3 (BX = 0: No Key, BX = 1: Left Button, BX = 2: Right Button, CX: X, DX: Y)
   - Position: AX = 4
   - Horizontal Limits: AX = 7 (CX: X1, DX: X2)
   - Vertical Limits: AX = 8 (CX: Y1, DX: Y2)

[Graphics]
* Text Video: 25 x 80 = 2000 Cells
   - 8-Bit: Character
   - 8-Bit: Color
   - Starting Address: 0xB8000000
* line, getmaxx, getmaxy, setcolor, setlinestyle, settextstyle, outtextxy, rectangle, circle, arc, bar, setfillstyle, setbkcolor, setfillstyle, setbkcolor, floodfill, cleardevice, getimage, putimage, imagesize

[File/Directory Mods]
* _chmod
   - Path
   - Read/Apply Attributes (0/1)
   - Dos File Attributes
* FA_RDONLY (Read-Only)
* FA_HIDDEN (Hidden)
* FA_SYSTEM (System)
* FA_LABEL (Volume Label)
* FA_DIRECT (Directory)
* FA_ARCH (Archive)
   - Fail Return: -1