#include<stdio.h> 

int main() 
{ 
    unsigned char a = 5, b = 9; // a = 5(00000101), b = 9(00001001) 
    printf("a = %d, b = %d\n", a, b); 
    printf("a&b = %d\n", a&b); // The result is 00000001 
    printf("a|b = %d\n", a|b);  // The result is 00001101 
    printf("a^b = %d\n", a^b); // The result is 00001100 
    printf("~a = %d\n", a = ~a);   // The result is 11111010 
    printf("b<<1 = %d\n", b<<1);  // The result is 00010010  
    printf("b>>1 = %d\n", b>>1);  // The result is 00000100  
    return 0; 
}




//%args:"Chi Troppo Vuole"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *xor(char *string, const char *key)
{
    char *s = string;
    size_t length = strlen(key), i = 0;
    while (*s) {
            *s++ ^= key[i++ % length];
    }
    return string;
}

void hexPrint(char *s)
{
    for (int i=0; i<strlen(s); i++) {
        printf("%02x ",s[i]);
    }
    puts("");
}

int main(int argc, char **argv)
{
    const char *key = "abcdefg";
    if (argc < 2) {
            fprintf(stderr, "%s: no input\n", argv[0]);
            return -1;
    }
    char *s=xor(argv[1],key);
    hexPrint(s);
    printf("%s\n", xor(s, key));
    
    return 0;
}




#include <stdio.h> 
#include <dirent.h> 

int main(void) 
{ 
    struct dirent *de; // Pointer for directory entry 

    // opendir() returns a pointer of DIR type. 
    DIR *dr = opendir("."); 
    if (!dr){ 
        perror("Opendir ."); 
        return -1; 
    } 

    while ((de = readdir(dr)) != NULL) {
        printf("%30s %ld\n", de->d_name,de->d_ino); 
    }
    closedir(dr);
    return 0; 
} 









//%args:work
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <time.h>


void printFileProperties(struct stat stats);


int main(int argc, char *argv[])
{
    char path[100];
    struct stat stats;

    if (argc!=2) {
        exit(-1);
    }
    
    // stat() returns 0 on successful operation,
    // otherwise returns -1 if unable to get file properties.
    if (stat(argv[1], &stats)) {
        perror("stat");
    }
    printFileProperties(stats);
    return 0;
}



/**
 * Function to print file properties.
 */
void printFileProperties(struct stat stats)
{
    struct tm dt;

    // File permissions
    printf("\nFile access: ");
    if (stats.st_mode & R_OK)
        printf("read ");
    if (stats.st_mode & W_OK)
        printf("write ");
    if (stats.st_mode & X_OK)
        printf("execute");

    // File size
    printf("\nFile size: %ld", stats.st_size);

    // Get file creation time in seconds and 
    // convert seconds to date and time format
    dt = *(gmtime(&stats.st_ctime));
    printf("\nCreated on: %d-%d-%d %d:%d:%d", dt.tm_mday, dt.tm_mon, dt.tm_year + 1900, 
                                              dt.tm_hour, dt.tm_min, dt.tm_sec);

    // File modification time
    dt = *(gmtime(&stats.st_mtime));
    printf("\nModified on: %d-%d-%d %d:%d:%d", dt.tm_mday, dt.tm_mon, dt.tm_year + 1900, 
                                              dt.tm_hour, dt.tm_min, dt.tm_sec);

}