Thread: copying a file

anyone know how to copy a file?
don't get it.
beginner.

Code:

#include <stdio.h>
#include <stdlib.h>
int main()
{
	system("copy filename.txt newfile.txt");

	return 0;
}

Works in MSVC++6 or VS.NET beta 2.

Fordy, when you say system, do you mean compiler?

The system command uses the command shell. It should work on all versions of Windows. But ofcourse it does not work on *nix, but who cares!

I like it because it is so simple to use. But in reality if it were my program I would use C# and the BCL. Not sure how to use File/IO yet with C#. But when I do, I'll be system independant because I'll target the .NET framework.

I think that most of the questions here on the C board are from students learning the C/C++ ANSI definitions. Although that might not always be the case. 'system' requires the Microsoft compiler, it is far easier to use than Win32. Look at the differences in the code!

BTW did you order the new Petzold yet?

thanks!

what about if you need the user to input the file they want copying?
beginner (slow beginner!)

Code:

#include <stdio.h>
#include <stdlib.h>
int main()
{
	system("cmd");
	printf("You typed exit, goodbye!\n");

	return 0;
}

Sure you could do it the way the previous poster suggested or else you can just open the shell and do whatever editing you want. It depends on the context of the program. The code the other poster suggested above asks for the name of the file and checks if that file exists by trying to open it. If it doesn't open than it doesn't exist. If it opens than you copy the contents of the file into the destination file with a buffer.

Just another example. It might be easier to read.

Code:

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

void CopyFile();
void GetFileName(char []);

int main()
{
	CopyFile();

	return 0;
}

void GetFileName(char filename[])
{
	fgets(filename,256,stdin);
	filename[ strlen(filename) -1 ] = '\0';

}

void CopyFile()
{
	char source[256];
	char dest[256];
	int character;

	printf("Enter source filepath: ");
	GetFileName(source);
	FILE *fsource = fopen(source,"r");
	if(fsource == NULL) 
	{
		printf("Source File Does Not Exist!");
		exit(1);
	}

	printf("Enter destination filepath: ");
	GetFileName(dest);
	FILE *fdest = fopen(dest,"w");

	while( fscanf(fsource,"%c", &character) != EOF)
		{
			fprintf(fdest, "%c", character);
		}
	printf("File copied sucessfully");
}