A simple brainfuck interpreter in C

bf.c

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

// initialize the tape with 30,000 zeroes
unsigned char tape[30000] = {0};
 
// set the pointer to point at the left-most cell of the tape
unsigned char* ptr = tape;


void interpret(char* input) {
    char current_char;
    size_t i;
    size_t loop;

    for (i = 0; input[i] != 0; i++) {
        current_char = input[i];
        if (current_char == '>') {
            ++ptr;
        } else if (current_char == '<') {
            --ptr;
        } else if (current_char == '+') {
            ++*ptr;
        } else if (current_char == '-') {
            --*ptr;
        } else if (current_char == '.' ) {
            putchar(*ptr);
        } else if (current_char == ',') {
            *ptr = getchar();
        } else if (current_char == '[') {
            continue;
        } else if (current_char == ']' && *ptr) {
            loop = 1;
            while (loop > 0) {
                current_char = input[--i];
                if (current_char == '[') {
                    loop--;
                } else if (current_char == ']') {
                    loop++;
                }
            }
        }
    }
}


int main() {
    interpret(",[.[-],]");  // outputs input
    return 0;
}

Did you use the tests on http://www.brainfuck.org/tests.b ?