Please look at this SIMPLE code

[abdul]

it is not simple for me but I am sure that it is all simple for you. I want create 4 or 5 files and name then like:

filenumber1 filenumber2 filenumber3 .....

I can create then individually but that is just a dirty way to do it

I have tried the following code but you can look at the result, and it is not what I am expecting

Code: 

char buffer;
	char filenom[] = "filenumber";
	const char *myfile = NULL;
	int i;
	FILE *files[5];
	for(i = 1; i < 5; i++)
	{
		buffer = (int)i;
		myfile = (filenom) + i;
		files[i] = fopen(myfile, "w+");
		cout<<myfile<<endl;
		fclose(files[i]);
	}

---------------------------------------------------------------------------------

Result:

It is just making 3 files with the names:

1) ilenumber
2)lenumber
3)lnumber

Why am I getting this result and how can I make the files with the correct name?

Please don't ignore

[HarryW]

This line is the problem:

myfile = (filenom) + i;

You can't add an int to a char*. You want to concatenate the fime number and the counter, and make a new string out of it. To do that you need to convert the int into a string using the itoa() function and then concatenate them using strcat(). Alternatively, and much more easily, you can use the sprintf() function, like this:

sprintf(myfile, "%s%d", filenom, i);

But you'll need to allocate a buffer for the string myfile when you declare it:

// used to be: const char *myfile = NULL
// now it should be:
char myfile[50];  // 50-byte buffer allocated

[abdul]

Thanks a lot!

Just one more thing:

What if I want to create the # of number use wants (eg 150 files)

Do I need to change to myfile buffer or I just change the value of i, and it will work file?

[Destined Soul]

Yes, increasing the limit of i should work. If you were to pass an integer "int someNumber" to the function, then you would use:

for (i = 1; i < someNumber; i++)
{
   sprintf(myfile,"%s%d",filenom,i);
   files[i] = fopen(myfile, "w+");
   cout<<myfile<<endl;
   fclose(files[i]);
}

Hope this helps

Destined.

[abdul]

Ok, that was working just one more:

I have created the files in a loop but how do open a certain file like "a.txt" and read 10 characters at a time, and write these characters to the files that I create in a loop like this:

file1 ----> 0 - 10 chars from a.txt
file2 ----> 11 - 20 chars from a.txt
file3 ----> 21-30 chars from a.txt

....and so on

Please?

[parksie]

This is code for a file splitter program I made once. It won't compile because a few of the classes are missing, but the theory's sound

#include <iostream>
#include <cmath>
#include <mjp/DirectFile.h>
#include <mjp/Defines.h>
#include <mjp/Tools.h>

#define BUF_SIZE 65536

using namespace std;

long round(float value) {
	// Round to nearest integer
	if((long)value == (long)(value + 0.5f))
		return (long)value;
	else
		return (long)(value+1);
}

void main(int argc, char **argv) {
	// splitter.exe file.ext partsize_kilobytes
	ulong ulPartSize;
	ubyte pubBuf[BUF_SIZE];
	ulong ulCount = 0;
	ulong ulTotal = 0;
	ulong ulNumParts = 0;
	DirectFile dfIn;
	DirectFile dfOut;

	if(argc < 3) {
		cout << "Usage: " << argv[0] << " filename partsize" << endl;
		return;
	}

	ulPartSize = atoi(argv[2]) * 1024; // size in bytes

	dfIn.OpenRead(argv[1], true);

	// Find number of parts
	// This statement adds one extra for the incomplete part
	ulNumParts = round((((float)(dfIn.Length())) / ((float)ulPartSize))) + 1;

	cout << "Number of parts = " << ulNumParts << endl;
	for(ulong j = 1; j <= ulNumParts; j++) {
		dfOut.OpenWrite((string(argv[1]) + "." + mjpTools::Long2String(j)).c_str(), true, true, false);

		for(ulong i = 0; i < ulPartSize; i) {
			ulTotal = ulPartSize - i;
			if(ulTotal >= BUF_SIZE) ulTotal = BUF_SIZE;
			ulCount = dfIn.Read(pubBuf, sizeof(ubyte), ulTotal);
			if(ulCount == 0 || ulCount == -1) break;
			dfOut.Write(pubBuf, sizeof(ubyte), ulCount);
			i += ulCount;
		}

		dfOut.Close();
	}

	dfIn.Close();
}