c++ ofstream ifstream 读写文件

c++ ofstream ifstream 读写文件
头文件

##include <fstream> #include <sstream>

ofstream 写文件

#define DATE_ONE "./log.txt"
int set_reporttime = curTime;
string set_businessid = "espn";
string set_stbid = "fffggh";

ofstream out(DATE_ONE,ios::out);
//  ios::out为输出（写）而打开文件，文件不存在则创建，若文件已存在则清空原内//容 ofstream默认的打开方式
//ios::app表示每次操作前均定位到文件末尾

if(out.fail())
{
 	cout<<"error\n";
}
out<<"set_reporttime:"<<set_reporttime<<"|"<<"set_businessid:"<<set_businessid<<"|"<<"set_stbid"<<set_stbid<<endl;

out.close();

ifstream 写文件

while(1)
{
	ifstream datefile("/log.txt");
	ostringstream buf;	
	char ch;
	string str;

	if (!access("/log.txt",0) ) 
	{
		cm_printf(LOG_LEVEL_DEBUG, "/log.txt EXISITS!"); 

		while(buf&&datefile.get(ch))
		{	
			buf.put(ch);
		}	
		 
		str = buf.str();
		
		cm_printf(LOG_LEVEL_DEBUG, "str: %s", str.c_str());
		datefile.close();

		//system("rm -rf ./log.txt");
		sleep(100);

	}
	else
	{
		cm_printf(LOG_LEVEL_DEBUG, "./log.txt not not not EXISITS!");
		sleep(100);
	}

}