返回随机文件名

#include 
#include 

using namespace std;

#include 

#ifdef WIN32
#include //_mkdir
#include   //_access
#else
#include     
#include     
#include     
#include     
#include     
#include   
#endif

/*
Title:  返回随机文件名。
Description: 如果当前目录下没有“年月日路径”目录创建它，并返回“时分秒+随机数”文件名。
Author: kagula
Date: 2016-03-14
Environment: 
VS2013 Update5
GCC 4.8.5
*/
string generateFileName(string pathPrefix, string filenameSuffix)
{
	string filname = pathPrefix;
	if (filname.empty())
	{
		filname = ".";
	}

	time_t now_time;
	now_time = time(NULL);
	struct tm *localTime;
	localTime = localtime(&now_time);

	int year = 1900 + localTime->tm_year;
	int month = 1 + localTime->tm_mon;
	char bufDate[64];
	char bufTime[64];
	sprintf(bufDate, "%04d_%02d_%02d",
		year, month, localTime->tm_mday);

	//check directory if exist, if not exist create it
	string dirname = pathPrefix;
	if (dirname.empty())
	{
		dirname = ".";
	}
	dirname.append("/");
	dirname.append(bufDate);
#ifdef WIN32
	if ((_access(dirname.c_str(), 0)) != 0)
	{
		if (_mkdir(dirname.c_str()) != 0)
		{
			return "";
		}
	}
#else
	if ((access(dirname.c_str(), R_OK)) != 0)
	{
		if (mkdir(dirname.c_str(), S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH) < 0)
		{
			return "";
		}
	}
#endif

	//
	int nR = (rand() % 10000) * 10000 + rand() % 10000;

	sprintf(bufTime, "%02d%02d%02d_%08d.%s",
		localTime->tm_hour, localTime->tm_min, localTime->tm_sec,
		nR, filenameSuffix.c_str());

	filname.append("/");
	filname.append(bufDate);
	filname.append("/");
	filname.append(bufTime);

	return filname;
}

int main(int argc, char* argv[])
{
	cout << "test file name generate" << endl;
	
	//
	srand(unsigned(time(0)));

	//
	for (int i = 0; i < 100; i++)
	{
		cout << "[" << i << "]  " << generateFileName("", "jpg") << endl;
	}

	cin.get();
	return 0;
}