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What are the uses of the exec command in shell scripts? [closed]
...ons in the kernel, there are a family of them based on execve, which is usually called from C.
exec replaces the current program in the current process, without forking a new process. It is not something you would use in every script you write, but it comes in handy on occasion. Here are some sce...
Does ruby have real multithreading?
...ing
models.
(Unfortunately, only two of those 11 implementations are actually
ready for production use, but by the end of the year that number
will probably go up to four or five.) (Update: it's now 5: MRI, JRuby, YARV (the interpreter for Ruby 1.9), Rubinius and IronRuby).
The first implement...
How to set top-left alignment for UILabel for iOS application?
...turn nil;
// set inital value via IVAR so the setter isn't called
_verticalAlignment = VerticalAlignmentTop;
return self;
}
-(VerticalAlignment) verticalAlignment
{
return _verticalAlignment;
}
-(void) setVerticalAlignment:(VerticalAlignment)value
{
_verticalAlignment = value...
How to Truncate a string in PHP to the word closest to a certain number of characters?
...ars, but the result would be cutting off in the middle of words-- what I really want is to chop the text at the end of the last word before 200 chars.
...
How to find third or nth maximum salary from salary table?
...
Use ROW_NUMBER(if you want a single) or DENSE_RANK(for all related rows):
WITH CTE AS
(
SELECT EmpID, EmpName, EmpSalary,
RN = ROW_NUMBER() OVER (ORDER BY EmpSalary DESC)
FROM dbo.Salary
)
SELECT EmpID, EmpName, EmpSalary
FROM CTE
WHERE RN = @NthRow
...
Usage of protocols as array types and function parameters in swift
...help overcome this limitation in some cases.
struct AnyX {
private let _x: () -> Int
var x: Int { return _x() }
init<T: X>(_ some: T) {
_x = { some.x }
}
}
// Usage Example
struct XY: X {
var x: Int
var y: Int
}
struct XZ: X {
var x: Int
var z: In...
How do you create a random string that's suitable for a session ID in PostgreSQL?
...
random() gets called length times (like in many of the other solutions). Is there a more efficient way to choose from 62 characters each time? How does this perform compared to md5()?
– ma11hew28
Feb 1...
Why do we need a pure virtual destructor in C++?
...
Probably the real reason that pure virtual destructors are allowed is that to prohibit them would mean adding another rule to the language and there's no need for this rule since no ill-effects can come from allowing a pure virtual destructor.
Nope, plain old virtual is enough.
If...
How to build & install GLFW 3 and use it in a Linux project
...
Step 1: Installing GLFW 3 on your system with CMAKE
For this install, I was using KUbuntu 13.04, 64bit.
The first step is to download the latest version (assuming versions in the future work in a similar way) from www.glfw.org, probably ...
线程访问窗口资源的问题 - C/C++ - 清泛网 - 专注C/C++及内核技术
...并行运行的窗口）。在工作线程里调用AfxGetMainWnd（）->m_hWnd出错，也会发生发生内存访问冲突。（AfxGetMainWnd得到的是当前线程的主窗口）。
2.ASSERT((p = pMap->LookupPermanent(m_hWnd)) != NULL ||
(p = pMap->LookupTemporary(m_hWnd)) != NULL)失败;从...