problem creating files

hi,

i have a problem with the "createFiles" function ...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
 /* reverse:  reverse string s in place */
 void reverse(char s[])
 {
     int i, j;
     char c;
 
     for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
         c = s[i];
         s[i] = s[j];
         s[j] = c;
     }
 }

 /* itoa:  convert n to characters in s */
// change from integer to a character
 void itoa(int n, char s[])
 {
     int i, sign;
 
     if ((sign = n) < 0)  /* record sign */
         n = -n;          /* make n positive */
     i = 0;
     do {       /* generate digits in reverse order */
         s[i++] = n % 10 + '0';   /* get next digit */
     } while ((n /= 10) > 0);     /* delete it */
     if (sign < 0)
         s[i++] = '-';
     s[i] = '\0';
     reverse(s);
 }


// returns the number of digits in the number
int num_of_digits(int x)
{
	int count = 0;
	while (x>0)
	{
		x = x/10;
		count++;
	}
	return count;
}
 
 
// creates the names for the files
void createNames(char name[][12], int size)
{
	char n[4];
	int digit = 0;
	
	for (int i=0; i<(size/2)+1; i++)
	{
		// inserting "file"
			name[i][0] = 'f';
			name[i][1] = 'i';
			name[i][2] = 'l';
			name[i][3] = 'e';
			
			itoa(i, n);
			digit = num_of_digits(i);
		// inserting a "number"
			if (digit <= 1)
			{
				name[i][4] = '0';
				name[i][5] = '0';
				name[i][6] = '0';
				name[i][7] = n[0];
			}
			else if (digit == 2)
			{
				name[i][4] = '0';
				name[i][5] = '0';
				name[i][6] = n[1];
				name[i][7] = n[0];
			}
			else if (digit == 3)
			{
				name[i][4] = '0';
				name[i][5] = n[2];
				name[i][6] = n[1];
				name[i][7] = n[0];
			}
			else if (digit == 4)
			{
				name[i][4] = n[3];
				name[i][5] = n[2];
				name[i][6] = n[1];
				name[i][7] = n[0];
			}
		
		// inserting the ".txt"
			name[i][8] = '.';
			name[i][9] = 't';
			name[i][10] = 'x';
			name[i][11] = 't';
	}
}

// creates new files
void createFiles(int size)
{
	FILE * pFile[6];
	char names[6][12];

	createNames(names, size);

	for (int i=0; i<6; i++)
	{
		pFile[i] = fopen(names[i], "w");
	}
}

int main ()
{
	int size = 10;		
	char name[6][12];	// an array of file names
	
	createNames(name, size);
	createFiles(size);
	
	// printing the files names
	for (int i=0; i<6; i++)
		{
			for (int j=0; j<12; j++)
				printf("%c",name[i][j]);
				
			printf("\n");
			}
	
	return 0;
}

the variable "names" is an array to hold the file names, and the "createNames" function creates file names so that later i can open files with the names generated.

my problem is that when i pass "names[i]" to the function fopen it does not only take the file name, instead it takes all the characters after it.

is there another way to pass the names of the files ? (like putting the name in a string then passing it)

hamsterman (4538)

The problem is that cstrings are terminated with '\0', and you never add it to the end.
Another problem is that you do things in an overly complicated way. Use http://www.cplusplus.com/reference/clibrary/cstdio/sprintf/ or something..

pirlo89 (17)

thank you very much. and thanks for the suggestion for using sprintf. i think it will simplify my code a lot.

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