source: MondoRescue/trunk/mindi-busybox/e2fsprogs/e2p/uuid.c@ 904

/*
 * uuid.c -- utility routines for manipulating UUID's.
 */

#include <stdio.h>
#include <string.h>
#include "../ext2fs/ext2_types.h"

#include "e2p.h"

struct uuid {
    __u32   time_low;
    __u16   time_mid;
    __u16   time_hi_and_version;
    __u16   clock_seq;
    __u8    node[6];
};

/* Returns 1 if the uuid is the NULL uuid */
int e2p_is_null_uuid(void *uu)
{
    __u8    *cp;
    int i;

    for (i=0, cp = uu; i < 16; i++)
        if (*cp)
            return 0;
    return 1;
}

static void e2p_unpack_uuid(void *in, struct uuid *uu)
{
    __u8    *ptr = in;
    __u32   tmp;

    tmp = *ptr++;
    tmp = (tmp << 8) | *ptr++;
    tmp = (tmp << 8) | *ptr++;
    tmp = (tmp << 8) | *ptr++;
    uu->time_low = tmp;

    tmp = *ptr++;
    tmp = (tmp << 8) | *ptr++;
    uu->time_mid = tmp;

    tmp = *ptr++;
    tmp = (tmp << 8) | *ptr++;
    uu->time_hi_and_version = tmp;

    tmp = *ptr++;
    tmp = (tmp << 8) | *ptr++;
    uu->clock_seq = tmp;

    memcpy(uu->node, ptr, 6);
}

void e2p_uuid_to_str(void *uu, char *out)
{
    struct uuid uuid;

    e2p_unpack_uuid(uu, &uuid);
    sprintf(out,
        "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
        uuid.time_low, uuid.time_mid, uuid.time_hi_and_version,
        uuid.clock_seq >> 8, uuid.clock_seq & 0xFF,
        uuid.node[0], uuid.node[1], uuid.node[2],
        uuid.node[3], uuid.node[4], uuid.node[5]);
}

const char *e2p_uuid2str(void *uu)
{
    static char buf[80];
    if (e2p_is_null_uuid(uu))
        return "<none>";
    e2p_uuid_to_str(uu, buf);
    return buf;
}