C/C++ Demonstration

This is the first repository I created in C++. I have been writing programs in C language for years. Some of them are even written with cpp extension. But I have never used some C++ features. So in this repo, I would like to show you some examples of C++ STL.

You should prepare all the libraries needed in order to generate Makefiles

Miscellaneous Executables

• vectordemo: A demonstration of std::vector. It's something similar to an array. But it contains more methods. It simply prints out everything inside the array.
• regexdemo: A demonstration of POSIX BRE written in C language using libgnurx because I can't use the standard C++11's regex library in MinGW.
• posixeredemo: A demonstration of POSIX ERE which stands for Extended Regular Expression, written in C language too. I recently discovered that the only difference is to add REG_EXTENDED in cflags.
• globalctors: A demonstration of GCC Global Constructor: A function that is automatically called before main.
• cpudemo: A x86-specific demonstration of getting CPU information using cpuid

Mathematics

• factor: This helps you factor any expressions that is in ax²+bx+c format. Following is the possible output

main: enter coefficient for: ax^2+bx+c
a=12
b=-7
c=-12
main: Processing 12x^2-7x-12...
(3x-4)(4x+3)

• squareroot: Re-implementation of sqrt() It uses the following steps to get the possible accurate value:

1. Guess a value called G
2. Check if G is close enough to the input/G
3. Return G if true, otherwise goto 1

• binarysearch: An implementation of searching node in an array with least comparisons.

Structures

• bitfield: A program that shows the value of struct with bitfield in the memory

struct{
	char a:1;
	char b:1;
	char c:1;
	char d:2;
} bitfield;

• structdemo: A program that shows difference between packed struct and default (aligned) struct.

Libraries

• libvoid: A set of functions that demonstrates generic type void*.

Function Prototypes	Description
void swap(void* ap,void* bp,size_t sz)	Switch the values between two generic pointers.
void* lsearch(void* key,void* base,size_t n,size_t each)	Search stuff from an unknown type array and returns the address of the result.
void* lsearchx(void* key,void* base,size_t n,size_t each,cmpfunc cmp)	Same as lsearch, but with a custom function for comparing values

Demonstrations of libvoid

• swapdemo: Demonstration of swap().
• searchdemo: Demonstration of lsearch().
• customcmpsearch: Demonstration of lsearchx().

Networking

• ipaddr: A tool to get IP address from your machine
• ftpdemo: Demonstration of FTP Protocol

Compile with -DVERBOSE helps show the response from server

Documents

• man_regex.txt: regular expression manual from Linux. I got function prototypes here.