test print_caps

void print_caps(const char *filename)
{
    struct vfs_cap_data cap_data;
    memset(&cap_data, 0, sizeof(cap_data));

    if (getxattr(filename, XATTR_NAME_CAPS, &cap_data, sizeof(cap_data)) < 0) {
        printf("print_caps on %s failed: %s\n", filename, strerror(errno));
    }
    else {
        printf("print_caps on %s result:\n", filename);
        printf("     magic_etc=%u \n", cap_data.magic_etc);
        printf("     data[0].permitted=%u \n", (uint32_t) cap_data.data[0].permitted);
        printf("     data[0].inheritable=%u \n", cap_data.data[0].inheritable);
        printf("     data[1].permitted=%u \n", (uint32_t) cap_data.data[1].permitted);
        printf("     data[1].inheritable=%u \n", cap_data.data[1].inheritable);
    }
}