utils.h

#include <dirent.h>
#include <sys/stat.h>

#define BUFFERSIZE 0x4000
#define COPYMORE 0644

bool is_empty(const char *path) {
    
    DIR *dir = opendir(path);
    struct dirent *ent;
    int count = 0;

    if ((dir = opendir(path)) == NULL) {
        printf("ERROR: Couldn't open directory: %s\n",path);
        exit(1);
    }
    
    while ((ent = readdir(dir)) != NULL) {
        count++;
    }

    closedir(dir);
    
    if (count == 2) {
        return YES;
    } else {
        return NO;
    }
}

int copy_dir(const char *from, const char *to);

int file_exists(const char* filename) {
    struct stat buffer;
    int exist = stat(filename,&buffer);
    if (exist == 0) {
        return 1;
    } else { // -1
        return 0;
    }
}

void oops(const char *msg, char *s2) {
    fprintf(stderr, "%s", msg);
    perror(s2);
}

int copyFiles(char *source, char *destination) {
    int in_fd, out_fd, n_chars;
    char buf[BUFFERSIZE];

    if ((in_fd = open(source, O_RDONLY)) == -1) {
        oops("Cannot open ", source);
        return 1;
    }

    if ((out_fd = creat(destination, COPYMORE)) == -1) {
        oops("Cannot creat ", destination);
        return 1;
    }

    while ((n_chars = read(in_fd, buf, BUFFERSIZE)) > 0) {
        if (write(out_fd, buf, n_chars) != n_chars) {
            oops("Write error to ", destination);
            return 1;
        }

        if (n_chars == -1) {
            oops("Read error from ", source);
            return 1;
        }
    }

    if (close(in_fd) == -1 || close(out_fd) == -1) {
        oops("Error closing files", "");
        return 1;
    }

    return 0;
}

int copy_dir(const char *name, const char *target) {
    DIR *dir;
    struct dirent *entry;

    if (!(dir = opendir(name))) return 1;
    
    mkdir(target, 0755);
    char path[1024];
    char targetpath[1024];
    int child = 0;
    while ((entry = readdir(dir)) != NULL) {
        snprintf(path, sizeof(path), "%s/%s", name, entry->d_name);
        snprintf(targetpath, sizeof(targetpath), "%s/%s", target, entry->d_name);
        if (entry->d_type == DT_DIR) {
            if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) continue;
        }
    	printf("Copying: %s...", path);
        child++;
        if (entry->d_type == DT_DIR) {
            if (mkdir(targetpath, 0755)) {
                perror("create folder");
            }
            if (!file_exists(targetpath)) {
                printf("Failed\n");
                continue;
            }
            printf("\n");
            copy_dir(path, targetpath);
        } else {
            if (copyFiles(path, targetpath) != 0) {
                printf("Failed\n");
            }
            printf("\n");
        }
    }
    closedir(dir);
    if (child == 0) {
        return 1;
    }
    return 0;
}