How do you make a library in C++

[thomasstambaugh]

I'm trying to make one that has some sorts in it for now.

I know you have to make a header file and a .cpp file.

I'm using VC++(yes, I'm in school so windows in needed. I use Ubuntu at home I swear D if it makes a difference.

What goes in the header file, how is the cpp file set up, and then where do I put the files once I'm done?

[thomasstambaugh]

Alright well this is my header


#ifndef SORT_H
#define SORT_H

void asort(int x[], int y);
void dsort(int x[], int y);

#endif


Here is the .cpp file my sorts are in


void asort(int x[],int n) {
int y,z,t;
for (y=1;y<=n;y++) {
for (z=0;z>=n-2;z++) {
if (x[z]<x[z+1]) {
t = x[z];
x[z] = x[z+1];
x[z+1] = t;
}
}
}
}

void dsort(int x[],int n) {
int y,z,t;
for (y=1;y<=n;y++) {
for (z=0;z<=n-2;z++) {
if (x[z]<x[z+1]) {
t = x[z];
x[z] = x[z+1];
x[z+1] = t;
}
}
}
}


And here is my main with the includes


#include "stdafx.h"
#include "sort.h"
#include <iostream>
using namespace std;

void main()
{
int x[10],y(10),z;
for (z=0;z<=9;z++) {
cout << "Enter: ";
cin >> x[z];
}

asort(x,y);

for (z=0;z<=9;z++)
cout << x[z];

}


All I get is build errors, and I'm gonna shoot and guess it has to do with me trying to call asort. What am I doing wrong

[Rubberman]

School project? You can't have a main() in a library.

[thomasstambaugh]

School project? You can't have a main() in a library.

The main isn't. The main is what is trying to run a function from the library. The library is the chunk of code above it.

I've tried googling the answers but everything on there is either about C or is just not making any sense.

In BASIC all I had to do was type LIBRARY "path here"

There has to be an easy or similar way to do this in C++, and I'm assuming that is what the #include "fdasgfdag.h" stuff is, however it seems to not be letting me use the functions in the library

[gerard4143]

Here's how to create a shared(shared object) library in Linux..I'm assuming that's what your after

testit.h

#ifndef SORT_H
#define SORT_H

void asort(int x[], int y);
void dsort(int x[], int y);

#endif

testit.cpp

void asort(int x[], int n) 
{
	int y, z, t;

	for (y=1; y <= n; y++) 
	{
		for (z=0;z>=n-2;z++) 
		{
			if (x[z]<x[z+1]) 
			{
				t = x[z];
				x[z] = x[z+1];
				x[z+1] = t;
			}
		}
	}
}

void dsort(int x[],int n) 
{
	int y, z, t;

	for (y = 1; y <= n; y++) 
	{
		for (z=0;z<=n-2;z++) 
		{
			if (x[z]<x[z+1]) 
			{
				t = x[z];
				x[z] = x[z+1];
				x[z+1] = t;
			}
		}
	}
}

test.cpp

#include <iostream>
#include "testit.h"

using namespace std;

int main()
{
	int x[10], y(10), z;

	for (z = 0; z <= 9; z++) 
	{
		cout << "Enter: ";
		cin >> x[z];
	}

	asort(x,y);

	for (z=0;z<=9;z++)
		cout << x[z];

	return 0;
}

And finally the compile lines

g++ -fPIC -c testit.cpp
ld -shared -o testit.so testit.o
g++ test.cpp ./testit.so -o test

[tpb261]

Are you sure it gives no compiler errors/warnings?
I am expecting an error/warning in the asort call:
asort(x,y) // x and y are arrays (pointers if you will)

asort defn. is asort(int[], int) // a pointer and a normal int

Try fixing that and check. But I am not sure if this question should be on the forum :P