大约有 5,475 项符合查询结果（耗时：0.0231秒） [XML]
How does password salt help against a rainbow table attack?
...for the purpose: let's say the attacker wants to build a rainbow table for 100,000 commonly used english words and typical passwords (think "secret"). Without salt she would have to precompute 100,000 hashes. Even with the traditional UNIX salt of 2 characters (each is one of 64 choices: [a–zA–Z...
Why is setTimeout(fn, 0) sometimes useful?
... 1.9)
function long_running(status_div) {
var result = 0;
// Use 1000/700/300 limits in Chrome,
// 300/100/100 in IE8,
// 1000/500/200 in FireFox
// I have no idea why identical runtimes fail on diff browsers.
for (var i = 0; i < 1000; i++) {
for (var j =...
What is the fastest method for selecting descendant elements in jQuery?
...hin 20 ops/sec to each other on most runs. Compared to 1 and 2, 4 is about 100-200 ops slower, and 5 is about 400 ops slower which is understandable because it goes through all descendants and not just children. Chart - tinyurl.com/25p4dhq
– Anurag
Jul 5 '10 at...
Fast Linux File Count for a large number of files
... in a particular directory when there are a very large number of files ( > 100,000).
18 Answers
...
How to copy from CSV file to PostgreSQL table with headers in CSV file?
I want to copy a CSV file to a Postgres table. There are about 100 columns in this table, so I do not want to rewrite them if I don't have to.
...
Is the “struct hack” technically undefined behavior?
...ch happens to point to an object which can legally be interpreted as char [100]; inside the allocated object.
– R.. GitHub STOP HELPING ICE
Sep 14 '10 at 23:34
3
...
How can I display just a portion of an image in HTML/CSS?
...
position: relative;
}
#clip {
position: absolute;
clip: rect(0, 100px, 200px, 0);
/* clip: shape(top, right, bottom, left); NB 'rect' is the only available option */
}
<div class="container">
<img src="http://lorempixel.com/200/200/nightlife/3" />
</div>
<di...
When should I use a table variable vs temporary table in sql server?
...MARY KEY, Flag BIT);
INSERT INTO @T
output inserted.* into #T
SELECT TOP 1000000 ROW_NUMBER() OVER (ORDER BY @@SPID), 0
FROM master..spt_values v1, master..spt_values v2
SET STATISTICS TIME ON
/*CPU time = 7016 ms, elapsed time = 7860 ms.*/
UPDATE @T SET Flag=1;
/*CPU time = 6234 ms, elapsed ...
const vs constexpr on variables
... value that is known at compile time.
For example:
constexpr int max = 100;
void use(int n)
{
constexpr int c1 = max+7; // OK: c1 is 107
constexpr int c2 = n+7; // Error: we don’t know the value of c2
// ...
}
To handle cases where the value of a “variable” that is initial...
Is there a way to pass optional parameters to a function?
...
def my_func(mandatory_arg, optional_arg=100):
print(mandatory_arg, optional_arg)
http://docs.python.org/2/tutorial/controlflow.html#default-argument-values
I find this more readable than using **kwargs.
To determine if an argument was passed at all, I use a...