大约有 45,000 项符合查询结果（耗时：0.0412秒） [XML]
Extract substring in Bash
...
If x is constant, the following parameter expansion performs substring extraction:
b=${a:12:5}
where 12 is the offset (zero-based) and 5 is the length
If the underscores around the digits are the only ones in the input, y...
Returning http status code from Web Api controller
...
I did not know the answer so asked the ASP.NET team here.
So the trick is to change the signature to HttpResponseMessage and use Request.CreateResponse.
[ResponseType(typeof(User))]
public HttpResponseMessage GetUser(HttpRequestMessag...
编译器内部的秘密--微软的编译器是如何解析Try/Catch/Throw的 - C/C++ - 清...
...
unsigned long __stdcall mainHandler1(LPEXCEPTION_POINTERS info)
{
if(info->ExceptionRecord->ExceptionCode != 0xE06D7363)
return EXCEPTION_CONTINUE_SEARCH; //非C++类异常，则继续寻找SEH链表的下个结构进行处理
if(WeHaveAHandlerForThisTypeSomeWhere(info->ExceptionRecord))...
python design patterns [closed]
... The third link is dead. Tried to find mirror but couldn't, If anybody has the correct link please add
– formatkaka
Oct 27 '16 at 12:40
1
...
What's the best way to send a signal to all members of a process group?
...
You don't say if the tree you want to kill is a single process group. (This is often the case if the tree is the result of forking from a server start or a shell command line.) You can discover process groups using GNU ps as follows:
p...
Should a return statement be inside or outside a lock?
...ideal, but I wouldn't bend the code out of shape just to achieve it... And if the alternative is declaring a local variable (outside the lock), initializing it (inside the lock) and then returning it (outside the lock), then I'd say that a simple "return foo" inside the lock is a lot simpler.
To sh...
Why return NotImplemented instead of raising NotImplementedError
...hould ask someone else to satisfy the operation. In the expression a == b, if a.__eq__(b) returns NotImplemented, then Python tries b.__eq__(a). If b knows enough to return True or False, then the expression can succeed. If it doesn't, then the runtime will fall back to the built-in behavior (which ...
Circle line-segment collision detection algorithm?
...
(x - h)2 + (y - k)2 = r2
(h,k) = center of circle.
Note: We've simplified the problem to 2D here, the solution we get applies also in 3D
to get:
Expand
x2 - 2xh + h2 + y2 - 2yk + k2 - r2 = 0
Plug
x = ex + tdx
y = ey + tdy
( ex + tdx )2 - 2( ex + tdx )h + h2 +
( ey + tdy )2 - 2( ey + tdy ...
What's the difference between echo, print, and print_r in PHP?
...ess the same; they are both language constructs that display strings. The differences are subtle: print has a return value of 1 so it can be used in expressions whereas echo has a void return type; echo can take multiple parameters, although such usage is rare; echo is slightly faster than print. (P...
What is the difference between 'my' and 'our' in Perl?
...
Great question: How does our differ from my and what does our do?
In Summary:
Available since Perl 5, my is a way to declare non-package variables, that are:
private
new
non-global
separate from any package, so that the variable cannot be accessed i...