#include <stdio.h> #include <stdlib.h> /**  * Create random UUID  *  * @param buf - buffer to be filled with the uuid string  */ char *random_uuid( char buf[37] ) {     const char *c = "89ab";     char *p = buf;     int n;     for( n = 0; n < 16; ++n )     {         int b = rand()%255;         switch( n )         {             case 6:                 sprintf(                     p,                     "4%x",                     b );                 break;             case 8:                 sprintf(                     p,                     "%c%x",                     c[rand()%strlen( c )],                     b );                 break;             default:                 sprintf(                     p,                     "x",                     b );                 break;         }         p += 2;         switch( n )         {             case 3:             case 5:             case 7:             case 9:                 *p++ = '-';                 break;         }     }     *p = 0;     return buf; }