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How to check if command line tools is installed

I have a macbook pro with OS X 10.8.2. XCode is installed. I know this as it appears in the Applications directory. There are also the xcodebuild and xcode-select files in /usr/bin I need to know if the command line tools is installed. Is there a command for it? What can I do to see if XCode CLT is ...
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Converting NSString to NSDate (and back again)

... totally worth checking this post. – iOmi Jan 22 '13 at 9:45 7 ...
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How to check if a process id (PID) exists

...kill to just check if a signal could be sent to the process, which is for most purposes more or less equivalent to checking if it exists. See linux.die.net/man/2/kill and linux.die.net/man/7/signal – Christoffer Hammarström Jun 15 '10 at 10:58 ...
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Will iOS launch my app into the background if it was force-quit by the user?

...E2: You can achieve this using the new PushKit framework, introduced in iOS 8. Though PushKit is used for VoIP. So your usage should be for VoIP related otherwise there is risk of app rejection. (See this answer). UDPDATE1: The documentation has been clarified for iOS8. The documentation can b...
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Why does an NSInteger variable have to be cast to long when used as a format argument?

... You get this warning if you compile on OS X (64-bit), because on that platform NSInteger is defined as long and is a 64-bit integer. The %i format, on the other hand, is for int, which is 32-bit. So the format and the actual parameter do not match in size. Since ...
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NSOperation vs Grand Central Dispatch

I'm learning about concurrent programming for iOS. So far I've read about NSOperation/NSOperationQueue and GCD . What are the reasons for using NSOperationQueue over GCD and vice versa? ...
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Can a local variable's memory be accessed outside its scope?

...n and replaced with a football stadium, and you are going to die in an explosion while you are sneaking around. You don't know what is going to happen; when you checked out of the hotel and stole a key to illegally use later, you gave up the right to live in a predictable, safe world because you c...
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Why doesn't JavaScript support multithreading?

...d updating an element accordingly will just let you see the start and end positions, and nothing in between. We use an abstraction library in JavaScript that allows us to create processes and threads which are all managed by the same JavaScript interpreter. This allows us to run actions in the foll...
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What should every programmer know about security? [closed]

... However, unfortunately it's almost impossible to instantiate the principle of least privilege in any modern system. For example, the Linux kernel (source I'm currently using) contains over 9.4 million lines of C code and over 400K lines of assembly, all of...
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Android - Start service on boot

... I have everything set up correctly to start an IntentService when Android OS boots. Unfortunately it is not starting on boot, and I'm not getting any errors. Maybe the experts can help... ...