number.c

#include <string.h>


int main(int argc,char*argv[]) {
    char CommandBuf[20];
    int a,b,sum;
    fprintf(stderr,"Please enter a number:");
    fgets(CommandBuf,20,stdin);
    a = atoi(CommandBuf);

    bzero(CommandBuf,20);
    fprintf(stderr,"Please enter another number:");
    fgets(CommandBuf,20,stdin);
    b = atoi(CommandBuf);

    if( a <= 0 || b <= 0 ){
        fprintf(stderr,"Can not smaller then 0!\n");
        exit(0);
    }

    /********************************************/
    /*  then we have to execute this command    */
    /********************************************/
    //
    //blah, blah, blah....
    //
    sum = a + b;
    if(sum == -10100){
        system("/checkin");
    }
    fprintf(stderr,"The sum is %d\n",sum);

    return 0;
}