compress with zlib

zcompress.cpp

#include <zlib.h>

bool zcompress(const string& input, string& output)
{
	z_stream z;

	z.zalloc = Z_NULL;
	z.zfree = Z_NULL;
	z.opaque = Z_NULL;

	output.resize(input.size() * 1.01 + 12);
	
	int status = Z_OK;
	
	status = deflateInit(&z, Z_DEFAULT_COMPRESSION);
	
	if(status != Z_OK)
	{
		return -1;
    }
	
	z.total_out = 0;
	z.next_in = (Bytef*)input.data();
	z.avail_in = input.size();
	
	do
	{
		z.next_out = (Bytef*)output.data() + z.total_out;
		z.avail_out = output.size() - z.total_out;
		status = deflate(&z, Z_FINISH);
	}
	while (status == Z_OK);
	
	output.resize(z.total_out);
	
	deflateEnd(&z);
}

Thank you for your code. That would be solved my issues.