Opening file in a for loop with a changing integer in title

[Chunder]

I am trying to convert a series of files into arrays. Each file is named molx.m where x is a number between 1-180. I am successfully able to convert one file to a matrix using the following code to open a file:

	FILE* fp = fopen("mol0.m", "r");
	fscanf(fp, "%i\n", &x);
	printf("X=%i\n", x);

        ...

However I now wish to create a for loop that will work through the array conversion routine for each file that I have. This means that on each run through the for loop I wish to open the file mol"y".m where y is a variable between 0-180. My problem is that I do not know how to insert the y into the filename. My initial thought was to try something akin to how you would use printf:

	FILE* fp = fopen(("mol%i.m", y) , "r");
	fscanf(fp, "%i\n", &x);
	printf("X=%i\n", x);
        ...

However on compilation this produces
"error: invalid conversion from ‘int’ to ‘const char*’
error: initializing argument 1 of ‘FILE* fopen(const char*, const char*)’"

I have tried changing the type of y to a char and get the same problem and char* which compiles but I get a segmentation fault when I try to run the program. I feel like I am missing something obvious here as it does not seem like a very difficult problem, any help would be appreciated. Thanks.

[shacktar]

sprintf will do what you want. itoa will also do it but it is not standard.

[Chunder]

Thanks for the help, if anyone is interested the code I used was:

	for(y=0; y<188; y++){

		sprintf(molname, "mol%i.m", y);
		printf("%s\n", molname);

		FILE* fp = fopen(molname, "r");
		fscanf(fp, "%i\n", &x);
		printf("X=%i\n", x);

                ...

Thanks again.