Parse GPS String for Time and Coordinates

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

void parse_gprmc(char *nmea) {
    char tokens[20][20];
    int i = 0, j = 0, top = 0;

    // Remove newline
    nmea[strcspn(nmea, "\n")] = '\0';

    // Split by comma
    while (nmea[i]) {
        if (nmea[i] != ',') {
            tokens[top][j++] = nmea[i];
        } else {
            tokens[top][j] = '\0';
            top++;
            j = 0;
        }
        i++;
    }
    tokens[top][j] = '\0';
    top++;

    // Check GPRMC
    if (strcmp(tokens[0], "$GPRMC") != 0) {
        printf("Not a GPRMC sentence\n");
        return;
    }

    // Time hhmmss
    printf("Time: ");
    printf("%c%c:%c%c:%c%c\n",
           tokens[1][0], tokens[1][1],
           tokens[1][2], tokens[1][3],
           tokens[1][4], tokens[1][5]);

    // Latitude
    printf("Latitude: %s %s\n", tokens[3], tokens[4]);

    // Longitude
    printf("Longitude: %s %s\n", tokens[5], tokens[6]);
}

int main() {
    char nmea[100];
    fgets(nmea, sizeof(nmea), stdin);
    parse_gprmc(nmea);
    return 0;
}