How to modify numbers in file "C"

[Mif]

Hello.. I want to modify a file that contain numbers which are divided by ",".
The numbers in file are represented like this:

Example

000.0,001.4,003.2,012.1
002.1,021.5,000.2,003.5
023.5,005.4,000.0,032.9

File after have been modified

0 1.4 3.2 12.1
2.1 21.5 0.2 3.5
23.5 5.4 0 32.9


So.. the modified new file have the numbers without the 0 (zeros) and instead of "," (comma) I need to put a horizontal tab between them, except last one because is the last number and comma is no needed.
Can someone help me understand how to do that?
Thanks in advance..

[lastchance]

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

istringstream test( "000.0,001.4,003.2,012.1\n"
                    "002.1,021.5,000.2,003.5\n"
                    "023.5,005.4,000.0,032.9\n" );

int main()
{
   double a, b, c, d;
   char comma;

   istream &in = test;
// ifstream in( "test.dat" );
   while ( in >> a >> comma >> b >> comma >> c >> comma >> d ) cout << a << '\t' << b << '\t' << c << '\t' << d << '\n';
}

0	1.4	3.2	12.1
2.1	21.5	0.2	3.5
23.5	5.4	0	32.9

[Mif]

:) nice... I have test that and works perfectly.. ty for your help. Now I'll try to reproduce that in C language.

Thank you so much

lastchance

!!!

[Mif]

And I'll try to do that opening a file.txt, and read it first, but that's enough I understand how it works.

[lastchance]

If you don't know how many items there are in a line then you could use the more general

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

istringstream test( "000.0,001.4,003.2,012.1\n"
                    "002.1,021.5,000.2,003.5\n"
                    "023.5,005.4,000.0,032.9\n" );

int main()
{
   istream &in = test;
// ifstream in( "test.dat" );
   for ( string s; getline( in, s ); )
   {
      stringstream ss( s );
      string number;
      while ( getline( ss, number, ',' ) ) cout << stod( number ) << '\t';
      cout << '\n';
   }
}

or

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

istringstream test( "000.0,001.4,003.2,012.1\n"
                    "002.1,021.5,000.2,003.5\n"
                    "023.5,005.4,000.0,032.9\n" );

int main()
{
   istream &in = test;
// ifstream in( "test.dat" );
   for ( string s; getline( in, s ); )
   {
      for ( char &c : s ) if ( c == ',' ) c = ' ';
      stringstream ss( s );
      for ( double d; ss >> d; ) cout << d << '\t';
      cout << '\n';
   }
}

[Mif]

That was an example , in a raw are 19 items and the file contains 4 raws.
So first I'll open the file with the FILE *pointer and I'll add your example.

[Mif]

Sorry I'm more with 'C' not C++ but I do understand what did you wrote :D
Thank you again..

[Mif]

Okay.. done in C language. A bit rudimentary but it works. :)

#include <Windows.h>
#include <stdio.h>

#pragma warning(disable: 4996) // disable fopen unsafe warning function (instead use fopen_s)

#define OLDFILE "before.txt"
#define NEWFILE "after.txt"

int main()
{
	remove(NEWFILE);
	FILE* oldFile = fopen(OLDFILE, "r");
	FILE* newFile = fopen(NEWFILE, "a+");
	float a;
		
	if(oldFile != NULL)
	{
		while (fgetc(oldFile) != EOF)
		{
			while (fscanf(oldFile, "%f", &a) == 1)
			{
				if (a == 0.0) fprintf(newFile, "%.0f\t", a);
				else fprintf(newFile, "%.1f\t", a);
			}
		}

		fclose(oldFile);
		fclose(newFile);
	}
	else
	{
		MessageBoxA(NULL, "before.txt does not exist, check the file", "Error !", MB_ICONERROR | MB_OK);
		fclose(newFile);
		remove(NEWFILE);
	}

	return (0);
}

[Mif]

I think I may have a mistake.. at the end of every line I forgot I don't have to print the horizontal TAB, well.. I believe that's pretty easy to correct.