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What's the difference between Perl's backticks, system, and exec?
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exec
executes a command and never returns.
It's like a return statement in a function.
If the command is not found exec returns false.
It never returns true, because if the command is found it never returns at all.
There is also no point in returning STDOUT, STDE...
What exactly is Arel in Rails 3.0?
I understand that it is a replacement for ActiveRecord and that it uses objects instead of queries.
4 Answers
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How can I make an svg scale with its parent container?
...g element's contents scale when size is non-native. Of course I could have it as a separate file and scale it like that.
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How do I integrate Ajax with Django applications?
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Even though this isn't entirely in the SO spirit, I love this question, because I had the same trouble when I started, so I'll give you a quick guide. Obviously you don't understand the principles behind them (don't take it as an offense, but if you did you wouldn't be a...
How do C++ class members get initialized if I don't do it explicitly?
Suppose I have a class with private memebers ptr , name , pname , rname , crname and age . What happens if I don't initialize them myself? Here is an example:
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Image width/height as an attribute or in CSS? [duplicate]
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It should be defined inline. If you are using the img tag, that image should have semantic value to the content, which is why the alt attribute is required for validation.
If the image is to be part of the layout or templat...
C# Object Pooling Pattern implementation
...ave a good resource on implementing a shared object pool strategy for a limited resource in vein of Sql connection pooling? (ie would be implemented fully that it is thread safe).
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Limitations of Intel Assembly Syntax Compared to AT&T [closed]
... Intel syntax, will I miss anything? Is there any reason I would want to switch to AT&T (outside of being able to read others' AT&T assembly)? My first clue is that gdb uses AT&T by default.
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Why do most C developers use define instead of const? [duplicate]
...ery solid reason for this: const in C does not mean something is constant. It just means a variable is read-only.
In places where the compiler requires a true constant (such as for array sizes for non-VLA arrays), using a const variable, such as fieldWidth is just not possible.
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How to prevent SIGPIPEs (or handle them properly)
...blem is that the client may have no interest in the answer sometimes and exits early, so writing to that socket will cause a SIGPIPE and make my server crash. What's the best practice to prevent the crash here? Is there a way to check if the other side of the line is still reading? (select() doesn't...