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Git: How to remove file from index without deleting files from any repository
...ware (directly out of a repository).
Keep File as a ‘Default’ and Manually/Automatically Activate It
If it is not completely unacceptable to continue to maintain the configuration file's content in the repository, you might be able to rename the tracked file from (e.g.) foo.conf to foo.conf.de...
Getting started with Haskell
...'ve done this by reading tutorials and watching screencasts, but nothing really seems to stick.
Now, in learning various imperative/OO languages (like C, Java, PHP), exercises have been a good way for me to go. But since I don't really know what Haskell is capable of and because there are many new c...
How to insert a text at the beginning of a file?
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To actually insert a new line: sed -i '1s/^/<added text> \n/' file
– jslatts
Sep 17 '13 at 13:27
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Why doesn't .NET/C# optimize for tail-call recursion?
...n was responsible for the machine code.
The CLR itself does support tail call optimization, but the language-specific compiler must know how to generate the relevant opcode and the JIT must be willing to respect it.
F#'s fsc will generate the relevant opcodes (though for a simple recursion it may j...
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...e to go with @Moody_Mudskipper's answer: Using .drop=FALSE can give potentially unexpected results when one or more grouping variables are not coded as factors. See examples below:
library(dplyr)
data(iris)
# Add an additional level to Species
iris$Species = factor(iris$Species, levels=c(levels(ir...
How to assign the output of a Bash command to a variable? [duplicate]
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In this specific case, note that bash has a variable called PWD that contains the current directory: $PWD is equivalent to `pwd`. (So do other shells, this is a standard feature.) So you can write your script like this:
#!/bin/bash
until [ "$PWD" = "/" ]; do
echo "$PWD"
ls ...
SQL Client for Mac OS X that works with MS SQL Server [closed]
How can I connect to a remote SQL server using Mac OS X? I don't really need a GUI, but it would be nice to have for the color coding and resultset grid. I'd rather not have to use a VM.
...
How to generate a random integer number from within a range
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All the answers so far are mathematically wrong. Returning rand() % N does not uniformly give a number in the range [0, N) unless N divides the length of the interval into which rand() returns (i.e. is a power of 2). Furthe...
Boolean operators && and ||
...es the longer form "appropriate for programming control-flow and [is] typically preferred in if clauses."
So you want to use the long forms only when you are certain the vectors are length one.
You should be absolutely certain your vectors are only length 1, such as in cases where they are funct...
Difference between a virtual function and a pure virtual function [duplicate]
... class. Derived classes can override virtual functions. Virtual functions called through base class pointers/references will be resolved at run-time. That is, the dynamic type of the object is used instead of its static type:
Derived d;
Base& rb = d;
// if Base::f() is virtual and Derived o...