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uniqid

uniqid

Generate a time-based identifier

string **uniqid** string $prefix bool $more_entropy

Gets an identifier based on the current time with microsecond precision, prefixed with the given and optionally appending a randomly generated value. prefix

Waarschuwing: > This function does not guarantee the uniqueness of the return value because the value is based on the current time in microseconds or the current time with a small amount of random data appended if is true. more_entropy

prefixCan be useful, for instance, if you generate identifiers simultaneously on several hosts that could generate the same identifier at the same microsecond. (This can happen even on a single host if the system clock is moved backwards, such as by an NTP adjustment.)

   With an empty , the returned string will
   be 13 characters long.  If  is
   true, it will be 23 characters.
  `prefix``more_entropy`

more_entropy If set to true, will add additional entropy (using the combined linear congruential generator) at the end of the return value, which increases the likelihood that the result will be unique. uniqid

Returns timestamp based identifier as a string.

Waarschuwing: > This function does not guarantee the uniqueness of the return value.

Voorbeeld: Example

<?php
/* A uniqid, like: 4b3403665fea6 */
printf("uniqid(): %s\r\n", uniqid());

/* We can also prefix the uniqid, this the same as 
 * doing:
 *
 * $uniqid = $prefix . uniqid();
 * $uniqid = uniqid($prefix);
 */
printf("uniqid('php_'): %s\r\n", uniqid('php_'));

/* We can also activate the more_entropy parameter, which is 
 * required on some systems, like Cygwin. This makes uniqid()
 * produce a value like: 4b340550242239.64159797
 */
printf("uniqid('', true): %s\r\n", uniqid('', true));
?>

Opmerking: > Under Cygwin, the must be set to true for this function to work. more_entropy

random_bytes

Vorige ← time_sleep_until Volgende unpack →

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