Форум

 
  
 #include <iostream> 
 #include <fstream> 
 #include <string> 
 #include <limits> 
 using namespace std; 
  
  
 std::fstream& GotoLine(std::fstream&File, unsigned int num){ 
  
 	File.seekg(std::ios::beg); 
 	for (int i = 0; i < num - 1 ; i++){ 
 	 
 		File.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); 
 	} 
  
 	return File; 
 } 
  
  
 int main(){ 
  
 	char *buf; 
 	string str1 = "abababab"; 
 	string str2 = "wjwjwjwjwjwj"; 
 	string str3 = "vivivivivivivivi"; 
 	int size1 = (str1.size()); 
 	int size2 = (str2.size()); 
 	int size3 = (str3.size()); 
  
 	string inp; 
 	int TS = 0; 
 	ofstream output("output.bin", ios::out | ios::binary);	if (!output)	{ 
 		cout << "can't open file" << endl;		exit(1); 
 	} 
  
 	for (int a = 1; a <= 3; a++){ 
  
 		if (a == 1){ inp = str1; TS = (str1.size()); } 
 		if (a == 2){ inp = str2; TS = (str2.size()); } 
 		if (a == 3){ inp = str3; TS = (str3.size()); } 
 		output.write(reinterpret_cast<char *>(&TS), sizeof(int)); 
 		output.write(inp.c_str(), TS); 
  
 	} 
  
 	str1 = str2 = str3 = ""; 
 	size1 = size2 = size3 = 0; 
 	TS = 0; 
 	output.flush();	output.close(); 
 	//======================================================================= 
 	ifstream input("output.bin", ios::in | ios::binary); 
  
 			if (!output)	{ 
 			cout << "can't open file" << endl;		exit(1); 
 		} 
  
  
 	//for (int i = 0; i <= 3; i++){ 
  
 	//	if (i == 1){  TS = (str1.size()); } 
 	//	if (i == 2){  TS = (str2.size()); } 
 	//	if (i == 3){  TS = (str3.size()); } 
  
 	//	input.read(reinterpret_cast<char *>(&TS), sizeof(int)); 
 	//	buf = new char[TS]; 
 	//	input.read(buf, TS); 
 	//	str1 = ""; 
 	//	str1.append(buf, TS); 
  
 	//	cout << str1 << endl; 
 	// 
 	//} 
 			fstream File("output.bin"); 
 			GotoLine(File, 1); 
  
 			string a; 
 			File >> a; 
  
 			cout << a << endl; 
  
 	 
 	return 0; 
  
 }
I created a function to access line in but only one line is returning
If i put 1in GotoLine(File, 1); its return but anything grater than 1 is not working