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Why is require_once so bad to use?
...system keeps a log of what's already been included/required. Every *_once call means checking that log. So there's definitely some extra work being done there but enough to detriment the speed of the whole app?
... I really doubt it... Not unless you're on really old hardware or doing it a lot.
I...
How to assign colors to categorical variables in ggplot2 that have stable mapping?
...maintain consistent color schemes across multiple data frames that are not all obtained by subsetting a single large data frame. Managing the factors levels in multiple data frames can become tedious if they are being pulled from separate files and not all factor levels appear in each file.
One way...
How to detect reliably Mac OS X, iOS, Linux, Windows in C preprocessor? [duplicate]
... Apple platform"
#endif
#elif __linux__
// linux
#elif __unix__ // all unices not caught above
// Unix
#elif defined(_POSIX_VERSION)
// POSIX
#else
# error "Unknown compiler"
#endif
The defined macros depend on the compiler that you are going to use.
The _WIN64 #ifdef can be nes...
Windows threading: _beginthread vs _beginthreadex vs CreateThread C++
...
CreateThread() is a raw Win32 API call for creating another thread of control at the kernel level.
_beginthread() & _beginthreadex() are C runtime library calls that call CreateThread() behind the scenes. Once CreateThread() has returned, _beginthread/ex...
Using os.walk() to recursively traverse directories in Python
I want to navigate from the root directory to all other directories within and print the same.
13 Answers
...
Using python's eval() vs. ast.literal_eval()?
...
datamap = eval(raw_input('Provide some data here: ')) means that you actually evaluate the code before you deem it to be unsafe or not. It evaluates the code as soon as the function is called. See also the dangers of eval.
ast.literal_eval raises an exception if the input isn't a valid Python dat...
Is the list of Python reserved words and builtins available in a library?
...break', 'class', 'continue', 'def',
'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import',
'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try',
'while', 'with', 'yield']
If you want to include built-in names as well (Python 3), then c...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
...ut this, but I gave up in the end, as the rules are somewhat diffuse. Basically, you’ll have to get the hang of it.
Perhaps it is best to concentrate on where curly braces and parenthesis can be used interchangeably: when passing parameters to method calls. You may replace parenthesis with curly b...
SQL: deleting tables with prefix
How to delete my tables who all have the prefix myprefix_ ?
10 Answers
10
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廉价共享存储解决方案1-drbd+ha+nfs - 更多技术 - 清泛网 - 专注C/C++及内核技术
...缓存的情况下可能会报目录不存在的错误，无视
yum clean all
yum makecache
3安装drbd(share1和2上操作)
3.1 准备编译环境
yum -y install gcc make automake autoconf flex rpm-build kernel-devel
3.2 上传解压源文件
利用xftp 把 drbd-8.4.6.tar.gz，d...