Manual Pages for UNIX Operating System command usage for man uuid_is_null

Universally Unique Identifier Library Functions
                                                uuid_clear(3UUID)



NAME
     uuid_clear,    uuid_compare,    uuid_copy,    uuid_generate,
     uuid_generate_random,    uuid_generate_time,   uuid_is_null,
     uuid_parse, uuid_time,  uuid_unparse  -  universally  unique
     identifier (UUID) operations

SYNOPSIS
     cc [ flag ... ] file... -luuid [ library ... ]
     #include 

     void uuid_clear(uuid_t uu);


     int uuid_compare(uuid_t uu1, uuid_t uu2);


     void uuid_copy(uuid_t dst, uuid_t src);


     void uuid_generate(uuid_t out);


     void uuid_generate_random(uuid_t out);


     void uuid_generate_time(uuid_t out);


     int uuid_is_null(uuid_t uu);


     int uuid_parse(char *in, uuid_t uu);


     time_t uuid_time(uuid_t uu, struct timeval *ret_tv);


     void uuid_unparse(uuid_t uu, char *out);


DESCRIPTION
     The uuid_clear() function sets the value  of  the  specified
     universally unique identifier (UUID) variable uu to the NULL
     value.


     The uuid_compare() function compares the two specified  UUID
     variables  uu1  and uu2 to each other. It returns an integer
     less than, equal to, or greater than zero if uu1 is found to
     be,  respectively,  lexicographically  less  than, equal, or
     greater than uu2.



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Universally Unique Identifier Library Functions
                                                uuid_clear(3UUID)



     The uuid_copy() function copies the  UUID  variable  src  to
     dst.


     The uuid_generate() function creates a new UUID that is gen-
     erated  based  on high-quality randomness from /dev/urandom,
     if   available.   If   /dev/urandom   is   not    available,
     uuid_generate()  calls uuid_generate_time(). Because the use
     of this algorithm provides information about when and  where
     the  UUID was generated, it could cause privacy problems for
     some applications.


     The uuid_generate_random() function produces a UUID  with  a
     random  or  pseudo-randomly  generated time and Ethernet MAC
     address that corresponds to a DCE version 4 UUID.


     The uuid_generate_time() function uses the current time  and
     the  local  Ethernet  MAC address (if available, otherwise a
     MAC address is fabricated) that corresponds to a DCE version
     1 UUID. If the UUID is not guaranteed to be unique, the mul-
     ticast bit is set (the high-order bit of octet number 10).


     The uuid_is_null() function compares the value of the speci-
     fied  UUID  variable  uu  to the NULL value. If the value is
     equal to the NULL  UUID,  1  is  returned.  Otherwise  0  is
     returned.


     The uuid_parse() function converts the UUID string specified
     by  in  to  the  internal uuid_t format. The input UUID is a
     string of the form cefa7a9c-1dd2-11b2-8350-880020adbeef.  In
     printf(3C)   format,  the  string  is  "%08x-%04x-%04x-%04x-
     %012x", 36 bytes plus the trailing null  character.  If  the
     input  string  is parsed successfully, 0 is returned and the
     UUID is stored in the location pointed to by  uu.  Otherwise
     -1 is returned.


     The uuid_time() function extracts  the  time  at  which  the
     specified  UUID uu was created. Since the UUID creation time
     is encoded within the UUID, this function can reasonably  be
     expected to extract the creation time only for UUIDs created
     with the uuid_generate_time() function. The  time  at  which
     the  UUID  was created, in seconds since January 1, 1970 GMT
     (the epoch), is returned (see time(2)). The  time  at  which
     the  UUID was created, in seconds and microseconds since the
     epoch is also stored in the location pointed  to  by  ret_tv
     (see gettimeofday(3C)).



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Universally Unique Identifier Library Functions
                                                uuid_clear(3UUID)



     The uuid_unparse() function converts the specified  UUID  uu
     from  the  internal  binary format to a string of the length
     defined in the uuid.h  macro,  UUID_PRINTABLE_STRING_LENGTH,
     which  includes  the  trailing null character. The resulting
     value is stored in the character string pointed to by out.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | Safe                        |
    |_____________________________|_____________________________|


SEE ALSO
     inetd(1M),   time(2),    gettimeofday(3C),    libuuid(3LIB),
     printf(3C), attributes(5)






























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Universally Unique Identifier Library Functions
                                                uuid_clear(3UUID)






















































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