Generate a random string which will be used as a UUID.

Makefile

all: rand_uuid

rand_uuid: rand_uuid.c
	gcc -o rand_uuid -O2 -Wall -W -ansi -pedantic -std=gnu99 rand_uuid.c

clean:
	rm -rf rand_uuid

rand_uuid.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

// Generate a random string which will be used
// as a UUID.
static char *_get_uuid(char *uuid, size_t uuid_sz)
{
    const char charset[] = "0123456789abcdefghijklmnopqrstuvwxyz";
    size_t charset_len = strlen(charset);

    if (uuid && uuid_sz)
    {
        for (size_t i = 0;i < uuid_sz;i++)
        {
            size_t rand_key = rand() % charset_len;
            uuid[i] = charset[rand_key];
        }
        uuid[uuid_sz] = '\0';
    }

    return uuid;
}

int main(int argc, char *argv[])
{
    char uuid[33];

    srand(time(NULL));

    strncpy (uuid, _get_uuid(uuid, sizeof(uuid)), sizeof(uuid));

    fprintf(stdout, "Rand UUID: %s\n", uuid);

    return 0;
}