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What's the difference between Perl's backticks, system, and exec?
...ere you want to fetch STDOUT, STDERR or the return code, you can use well known standard modules like IPC::Open2 and IPC::Open3.
Example:
use IPC::Open2;
my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'some', 'cmd', 'and', 'args');
waitpid( $pid, 0 );
my $child_exit_status = $? >> 8;
Finally, IPC:...
Removing empty lines in Notepad++
...
There is now a built-in way to do this as of version 6.5.2
Edit -> Line Operations -> Remove Empty Lines or Remove Empty Lines (Containing Blank characters)
...
Making HTTP Requests using Chrome Developer tools
...ince the Fetch API is supported by Chrome (and most other browsers), it is now quite easy to make HTTP requests from the devtools console.
To GET a JSON file for instance:
fetch('https://jsonplaceholder.typicode.com/posts/1')
.then(res => res.json())
.then(console.log)
Or to PO...
Python vs Bash - In which kind of tasks each one outruns the other performance-wise? [closed]
...lly runs a short Bash script. That script, either directly or indirectly, knows where all the files needed are and sets variables and command line parameters, finally calling the program. That's a shell's simplest use.
Linux as we know it however would hardly be Linux without the thousands of shell...
How do function pointers in C work?
... which receives 2 ints and returns an int:
int (*functionPtr)(int,int);
Now we can safely point to our function:
functionPtr = &addInt;
Now that we have a pointer to the function, let's use it:
int sum = (*functionPtr)(2, 3); // sum == 5
Passing the pointer to another function is basica...
UILabel sizeToFit doesn't work with autolayout ios6
...If we run the app in the simulator, sure enough, we see the same thing:
Now, let's select the UILabel in Interface Builder, and take a look at the default settings in the Size inspector:
Note the highlighted constraint above. That is the Content Hugging Priority. As Erica Sadun describes it in...
What does this mean: Failure [INSTALL_FAILED_CONTAINER_ERROR]?
...ecure folder, only root has access. I was able to run the app before, only now since a while, cannot run it and it gives the above error.
– Mathias Conradt
Apr 21 '11 at 13:27
1
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error: ‘NULL’ was not declared in this scope
...
Now that C++11 is more generally supported by compilers, it might be worth mentioning the nullptr keyword, which is an actual keyword and doesn't require any #includes. It's also more typesafe than NULL.
...
On delete cascade with doctrine2
...also want to point out that the way you have your cascade={"remove"} right now, if you delete a Child object, this cascade will remove the Parent object. Clearly not what you want.
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What is “lifting” in Haskell?
...rn than a mathematical concept (although I expect someone around here will now refute me by showing how lifts are a category or something).
Typically you have some data type with a parameter. Something like
data Foo a = Foo { ...stuff here ...}
Suppose you find that a lot of uses of Foo take nu...