How to use C + + + line reading TXT file string (can be conveniently implemented text file replication) __c++

This code has been tested under windows/vc++6.0, and there is no problem under linux/g++.

but be sure to be aware of the differences between Linux and Windows file formats, For example:

1. When code on Linux reads the Windows file format, there will be one more per row for reading the result. \ r, think about why.

2. When code on Windows reads a Linux format file, the read results show only one line and think about why.

First in C language to write an ugly program:

#include <stdio.h>
#include <stdlib.h>
int main ()
{
	FILE *fp;
	if (NULL = = (fp = fopen ("1.txt", "R")))
	{
		printf ("error\n");
	    Exit (1);
	}

	char ch;
	while (EOF!= (CH=FGETC (FP))
	{
		printf ("%c", ch);
	}

	Fclose (FP);

	return 0;
}

You can only see the result, but you can't use every line. We will instead:

vc++6.0

#include <stdio.h>
#include <string.h>

int main ()
{
	char sztest[1000] = {0 };
	int len = 0;

	FILE *FP = fopen ("1.txt", "R");
	if (NULL = fp)
	{
		printf ("Failed to open dos.txt\n");
		return 1;
	}

	while (!feof (FP))
	{
		memset (sztest, 0, sizeof (sztest));
		Fgets (sztest, sizeof (sztest)-1, FP); Contains a newline character
		printf ("%s", sztest);
	}

	Fclose (FP);

	printf ("\ n");

	return 0;
}

So we just read the whole row.

feel C reading method a bit ugly, or see C + + bar (as long as the file format Windows/linux and compile platform windows/linux correspondence, you can rest assured that use it):

#include <fstream>
#include <string>
#include <iostream>
using namespace std;

int main ()
{
	ifstream in ("1.txt");
	string filename;
	string line;

	if (in)//There is a
		newline character
		{ 
			cout << line << endl;
  
   
	/else//does not have the file
	{
		cout << "No such file" << Endl;
	}

	return 0;
}
  

Of course, you can modify the above program so that each line in 1.txt is entered into 2.txt, as follows:

#include <fstream>
#include <string>
#include <iostream>
using namespace std;

int main ()
{
	ifstream in ("1.txt");
	Ofstream out ("2.txt");
	string filename;
	string line;

	if (in)//There is a
		newline character
		{ 
			cout << line << endl;
  out << line << Endl; Input to 2.txt
		}
	else//does not have the file
	{
		cout << "No such file" << Endl;
	}

	return 0;
}

As a result, the content of 2.txt and 1.txt is exactly the same, you can compare it with beyond compare, I compare it.

It seems that the above procedures can also achieve the duplication of documents, as follows:

#include <fstream>
#include <string>
#include <iostream>
using namespace std;

void FileCopy (char *file1, char *file2)
{
	//is best judged on file1 and File2
	
	ifstream in (file1);
	Ofstream out (file2);
	string filename;
	string line;

	while (Getline (on)) {out 
		<< line << Endl;
	}
}

int main ()
{
	filecopy ("1.txt", "2.txt");
	return 0;
}

Of course, the above program is only for text files (not just. txt), not for other types of files.