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Why is the gets function so dangerous that it should not be used?
...icial part of the language up to the 1999 ISO C standard, but
it was officially removed by the 2011 standard. Most C implementations still support it, but at least gcc issues a warning for any code that uses it.
share
...
Difference between variable declaration syntaxes in Javascript (including global variables)?
...here are a couple of differences, though in practical terms they're not usually big ones.
There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:
var a = 0; // 1
let a = 0; // 1...
Converting JSON String to Dictionary Not List
...datapoints[0][0]). Just to list them, I tried doing datapoints[0:5][0] but all I get is the first datapoint with both elements as opposed to wanting to get the first 5 datapoints containing only the first element. Is there a way to do this?
datapoints[0:5][0] doesn't do what you're expecting. dat...
OpenSSH升级后不能登录的问题 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...顺利
具体情况这里http://pkgs.org/centos-6/ghettoforge-testing-x86_64/openssh-6.6.1p1-4.gf.el6.x86_64.rpm.html
备份原有源
cd /etc/yum.repos.d/
mv rhel-source.repo rhel-source.repo.bak
mv packagekit-media.repo packagekit-media.repo.bak
配置源
vi CentOS-Base.repo
[base]
name...
Fastest way to determine if an integer's square root is an integer
... CPU (x86) and programming language (C/C++). Your results may vary, especially because I don't know how the Java factor will play out.
My approach is threefold:
First, filter out obvious answers. This includes negative numbers and looking at the last 4 bits. (I found looking at the last six di...
Better way to sum a property value in an array
...
Updated Answer
Due to all the downsides of adding a function to the Array prototype, I am updating this answer to provide an alternative that keeps the syntax similar to the syntax originally requested in the question.
class TravellerCollection e...
Run a single migration file
...f the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require returns an array of class names:
sc...
Golang tests in sub-directory
...
Note that you can run go test "recursively": you need to list all the packages you want to test.
If you are in the root folder of your Go project, type:
go test ./...
The './...' notation is described in the section "Description of package lists" of the "command go":
An import path is...
Why does volatile exist?
...ed 16 bit value as a semaphore to know when the other guy was done. Essentially we did this:
void waitForSemaphore()
{
volatile uint16_t* semPtr = WELL_KNOWN_SEM_ADDR;/*well known address to my semaphore*/
while ((*semPtr) != IS_OK_FOR_ME_TO_PROCEED);
}
Without volatile, the optimizer sees ...
How do you iterate through every file/directory recursively in standard C++?
...e to the standard.
An example, taken straight from the website:
bool find_file( const path & dir_path, // in this directory,
const std::string & file_name, // search for this name,
path & path_found ) // placing path here if found
{
...