【C++】C++常用小函数

提取文件名、后缀

#include <string> 
using namespace std;

string getFilenameNoSufffix(string path){
    
    
	string::size_type iPos = (path.find_last_of('\\') + 1) == 0 ?  path.find_last_of('/') + 1: path.find_last_of('\\') + 1 ;
	//std::string FileName = path.substr(iPos, path.length() - iPos);//获取带后缀的文件名
	//string suffix= path.substr(path.rfind(".") + 1, path.length());//获取后缀名,不带.
	string FilenameNoSufffix = path.substr(iPos, path.rfind(".")-iPos);//获取不带后缀的文件名
	return FilenameNoSufffix;
}

int转string并高位补0

#include <string> 
#include <sstream>
using namespace std;
string int2stringAdd0(int num, int max_num){
    
    
	int length = std::to_string(max_num).size();
	stringstream ss;
	ss << setw(length) << setfill('0') << num ;
	string str;
	ss >> str;
	return str;	
}

创建目录

#include <string> 
using namespace std;

bool createDirectorys(string path){
    
    
	string cmd("mkdir -p " + path);
	int ret = system(cmd.c_str());
	if (ret)
	{
    
    
		cout << "error when create directories : " << ret << ", :" << strerror(errno) << endl;
		return 0;
	}
	cout << "successfully create directories: " << path << endl;

	return 1;
} 

生成随机数

#include <time.h>
#include <stdlib.h>


int randMin2Max(int min, int max){
    
    
	srand(time(0));
	int num = rand() % int(max - min + 1) + min;  //[min,max]
	int num = rand() % int(max - min) + min;  //[min,max)
	int num = rand() % int(max - min) + min + 1;  //(min,max]
	return num;
	
int rand_aroundX(int x, float y){
    
    
	# y是随机数在x附近的振荡范围，如取0.05，则随机数的范围是[0.95x, 1.05x]
	srand(time(0));
	int num= rand() % int(x*y*2 + 1) + int(x*(1-y)); 
	return num;
}