Function getRandomHexChars

app/redis-6.2.6/src/util.c:715–721

Generate the Redis "Run ID", a SHA1-sized random number that identifies a * given execution of Redis, so that if you are talking with an instance * having run_id == A, and you reconnect and it has run_id == B, you can be * sure that it is either a different instance or it was restarted. */

 * having run_id == A, and you reconnect and it has run_id == B, you can be
 * sure that it is either a different instance or it was restarted. */
void getRandomHexChars(char *p, size_t len) {
    char *charset = "0123456789abcdef";
    size_t j;

    getRandomBytes((unsigned char*)p,len);
    for (j = 0; j < len; j++) p[j] = charset[p[j] & 0x0F];
}

/* Given the filename, return the absolute path as an SDS string, or NULL
 * if it fails for some reason. Note that "filename" may be an absolute path