sprintf buffer sizes
buffer, c, printf
Solution
You're forgetting the NUL terminator. In C, strings require an extra character for the terminator, so `char buf[2]` ought to be `char buf[3]` to accommodate numbers between 10 and 99.
Incidentally, your code demonstrates why `sprintf` is dangerous as it can write past the output buffer and enable stack smashing attacks. A better options is to use `snprintf`.
Problem
I'm a novice programmer, but usually I can unravel my own issues. This time I solved the issue, but it still stumps me. A friend suggested I ask this community for input. I'm trying to print numbers in C. I have a function to do this using sprintf. The numbers should never be more than 2 digits so I use a 2-character buffer. Somehow this is where my logic fails, because this causes an infinite loop by modifying one of the variables passed to sprintf, but increasing the buffer size solves the issue. Here's the failing code: ``` #include <stdio.h> void printarray(int array[][4]) { int y; int z; char buf[2]; for (y=0; y<4; y++) { for (z=0; z<4; z++) { sprintf(buf, "%d", array[y][z]); printf("buf is %s, y is %d and z is %d\n",buf,y,z); } } } int main() { int arr[4][4] = { {1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,0} }; printarray(arr); return 0; } ``` as soon as y gets to 2, it gets reset back to 0, thus infinite loop. changing buf[2] to buf[8] solves the issue.