C / C++ / MFC

ofstream out("/Users/Dixon/test1.txt");
if (not out)
    perror("/Users/Dixon/test1.txt");
else {
    out << "1" << "2" << "3" << "4" << "5" << "6";
    out.close();

    ifstream in("/Users/Dixon/test1.txt");
    if (not in)
        perror("/Users/Dixon/test1.txt");
    else {
        int x(0);
        while (in >> x)
        {
            cout << x << '\n';
        }
        in.close();
    }

}

#include <iostream>
#include <fstream>
#include <string>

int main () {
	using namespace std;
	
	string line;
	ifstream myfile("/Users/Dixon/test1.txt");
	if (myfile.is_open())
	{
		while (! myfile.eof())
		{
			getline(myfile,line);
			cout << line << endl;
		}
		myfile.close();
	}
	else {
		cout << "Unable to open file";
	}
	
	return 0;

}

Jacob Dixon wrote:

#include <cstdio>
#include <fstream>
#include <istream>
#include <ostream>
#include <iostream>

Jacob Dixon wrote:

if (not in)

if (in.fail())

Rajesh R Subramanian wrote:

You could use strcat()[^] to concatenate strings.

sampath-padamatinti wrote:

Actually my requirement is "not use the strcat() function".

char* concat(const char* c1, const char* c2)

sampath-padamatinti wrote:

I am unable to solve this one. Please give me the approach

char * concat(const char * c1, const  char * c2)
{
  size_t size[2] = {strlen(c1), strlen(c2)};
  char * c = new char[size[0]+size[1]+1];
  strcpy(c, c1);
  strcpy(c+size[0],c2);
  return c;
}

char * concat(const char * c1, const char * c2)
{
  size_t len=0;
  char * c;
  const char *p;
  p = c1;
  while (*p++) len++;
  p = c2;
  while (*p++) len++;
  c = new char[len+1];
  p=c1;
  while (*c=*p++) c++;
  p=c2;
  while (*c++=*p++) ;  
  return (c-len-1);
}

void main()
{
  const char * str1 = "hello, ";
  const char * str2 = "folks!";
  char * result = concat(str1, str2);
  printf("%s\n", result);
  delete [] result;
}