php 检查字符串是否为unix时间戳
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Check whether the string is a unix timestamp
提问by RHPT
I have a string and I need to find out whether it is a unix timestamp or not, how can I do that effectively?
我有一个字符串，我需要确定它是否是 unix 时间戳，我怎样才能有效地做到这一点？
I found this threadvia Google, but it doesn't come up with a very solid answer, I'm afraid. (And yes, I cribbed the question from the original poster on the aforementioned thread).
我通过谷歌找到了这个线程，但恐怕没有给出一个非常可靠的答案。（是的，我从上述线程的原始海报中抄袭了这个问题）。
回答by Gordon
Ok, after fiddling with this for some time, I withdraw the solution with date('U')and suggest to use this one instead:
好的，在摆弄了一段时间后，我撤回了解决方案date('U')并建议改用这个：
function isValidTimeStamp($timestamp)
{
return ((string) (int) $timestamp === $timestamp)
&& ($timestamp <= PHP_INT_MAX)
&& ($timestamp >= ~PHP_INT_MAX);
}
This check will only return true if the given $timestampis a stringand consists solely of digits and an optional minus character. The number also has to be within the bit range of an integer (EDIT: actually unneeded as shown here).
如果给定的$timestamp是字符串并且仅由数字和可选的减号组成，则此检查将仅返回 true 。该数字还必须在整数的位范围内（编辑：实际上不需要，如此处所示）。
var_dump( isValidTimeStamp(1) ); // false
var_dump( isValidTimeStamp('1') ); // TRUE
var_dump( isValidTimeStamp('1.0') ); // false
var_dump( isValidTimeStamp('1.1') ); // false
var_dump( isValidTimeStamp('0xFF') ); // false
var_dump( isValidTimeStamp('0123') ); // false
var_dump( isValidTimeStamp('01090') ); // false
var_dump( isValidTimeStamp('-1000000') ); // TRUE
var_dump( isValidTimeStamp('+1000000') ); // false
var_dump( isValidTimeStamp('2147483648') ); // false
var_dump( isValidTimeStamp('-2147483649') ); // false
The check for PHP_INT_MAX is to ensure that your string can be used correctly by dateand the likes, e.g. it ensures this doesn't happen*:
检查 PHP_INT_MAX 是为了确保您的字符串可以被诸如此类的人正确使用date，例如它确保不会发生这种情况*：
echo date('Y-m-d', '2147483648'); // 1901-12-13
echo date('Y-m-d', '-2147483649'); // 2038-01-19
On 64bit systems the integer is of course larger than that and the function will no longer return false for "2147483648" and "-2147483649" but for the corresponding larger numbers.
在 64 位系统上，整数当然比那个大，函数将不再为“2147483648”和“-2147483649”返回假，而是为相应的更大的数字返回假。
(*) Note: I'm not 100% sure, the bit range corresponds with what date can use though
(*)注意：我不是 100% 确定，位范围与可以使用的日期相对应
回答by Yacoby
As a unix timestamp is a integer, use is_int(). However as is_int() doesn't work on strings, we check if it is numeric and its intergal form is the same as its orignal form. Example:
由于 unix 时间戳是整数，因此请使用is_int()。然而，由于is_int() 不适用于字符串，我们检查它是否是数字并且它的整数形式与其原始形式相同。例子：
( is_numeric($stamp) && (int)$stamp == $stamp )
回答by simplychrislike
I came across the same question and created the following solution for my self, where I don't have to mess with regular expressions or messy if-clauses:
我遇到了同样的问题，并为我自己创建了以下解决方案，在那里我不必弄乱正则表达式或凌乱的 if 子句：
/**
* @param string $string
* @return bool
*/
public function isTimestamp($string)
{
try {
new DateTime('@' . $string);
} catch(Exception $e) {
return false;
}
return true;
}
回答by TD_Nijboer
this looks like the way to go:
这看起来像要走的路：
function is_timestamp($timestamp) {
if(strtotime(date('d-m-Y H:i:s',$timestamp)) === (int)$timestamp) {
return $timestamp;
} else return false;
}
you could also add a is_numeric() check and all sort of other checks.
but this should/could be the basics.
您还可以添加 is_numeric() 检查和所有其他检查。
但这应该/可能是基础知识。
回答by Dimitar Darazhanski
Improved answer to @TD_Nijboer.
改进了对@TD_Nijboer 的回答。
This will avoid an exception be thrown if the supplied string is not a time stamp:
如果提供的字符串不是时间戳，这将避免抛出异常：
function isTimestamp($timestamp) {
if(ctype_digit($timestamp) && strtotime(date('Y-m-d H:i:s',$timestamp)) === (int)$timestamp) {
return true;
} else {
return false;
}
回答by goat
This doesn't account for negative times(before 1970), nor does it account for extended ranges(you can use 64 bit integers so that a timestamp can represent a value far after 2038)
这不考虑负时间（1970 年之前），也不考虑扩展范围（您可以使用 64 位整数，以便时间戳可以表示远在 2038 年之后的值）
$valid = ctype_digit($str) && $str <= 2147483647;
回答by Patrick Cornelissen
You want to check if a string contains a high number?
你想检查一个字符串是否包含一个大数字？
is_numeric() is the key
is_numeric() 是关键
Or convert it to DateTime and do some checks with it like an expected date range.
或者将其转换为 DateTime 并对其进行一些检查，例如预期的日期范围。
回答by alex toader
or
或者
if ($startDate < strtotime('-30 years') || $startDate > strtotime('+30 years')) {
//throw exception
}
回答by Aleksandr Matiushkin
If you might think to replace thissolution with is_numeric(), please consider that php native function provides false positives for input strings like "1.1", "0123", "0xFF" which are not in timestamp format.
如果您可能想用is_numeric()替换此解决方案，请考虑 php 本机函数为诸如“1.1”、“0123”、“0xFF”之类的非时间戳格式的输入字符串提供误报。
回答by Chris
Another possibility:
另一种可能：
$date_arg = time();
$date_is_ok = ($date_arg === strtotime(date('c', $date_arg)));
