大约有 45,000 项符合查询结果（耗时：0.0580秒） [XML]
How do I check if file exists in Makefile so I can delete it?
...
The second top answer mentions ifeq, however, it fails to mention that these must be on the same level as the name of the target, e.g., to download a file only if it doesn't currently exist, the following code could be used:
download:
ifeq (,$(wildcard ./glob.c))
cur...
Add Keypair to existing EC2 instance
I was given AWS Console access to an account with 2 instances running that I cannot shut down (in production). I would however like to gain SSH access to these instances, is it possible to create a new Keypair and apply it to the instances so I can SSH in? Obtaining the exisiting pem file for the ke...
When to use reinterpret_cast?
I am little confused with the applicability of reinterpret_cast vs static_cast . From what I have read the general rules are to use static cast when the types can be interpreted at compile time hence the word static . This is the cast the C++ compiler uses internally for implicit casts also.
...
SHA512 vs. Blowfish and Bcrypt [closed]
I'm looking at hashing algorithms, but couldn't find an answer.
6 Answers
6
...
Creating an API for mobile applications - Authentication and Authorization
I'm looking to create a (REST) API for my application. The initial/primary purpose will be for consumption by mobile apps (iPhone, Android, Symbian, etc). I've been looking into different mechanisms for authentication and authorization for web-based APIs (by studying other implementations). I've ...
When NOT to call super() method when overriding?
When I make my own Android custom class, I extend its native class. Then when I want to override the base method, I always call super() method, just like I always do in onCreate , onStop , etc.
...
Differences between socket.io and websockets
...
Its advantages are that it simplifies the usage of WebSockets as you described in #2, and probably more importantly it provides fail-overs to other protocols in the event that WebSockets are not supported on the browser or se...
Variable declared in for-loop is local variable?
I have been using C# for quite a long time but never realised the following:
9 Answers
...
Why does Hibernate require no argument constructor?
... no-arg constructor, since serialization uses jvm magic to create objects without invoking the constructor. But this is not available across all VMs. For example, XStream can create instances of objects that don't have a public no-arg constructor, but only by running in a so-called "enhanced" mode w...
Do I really have a car in my garage? [duplicate]
...stract int getPriceAfterYears(int years);
}
Every Vehicle has a price so it can be put inside the Vehicle abstract class.
Yet, the formula determining the price after n years depends on the vehicle, so it left to the implementing class to define it. For instance:
public Car extends Vehicle {
...