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How to get the last N records in mongodb?
...need to sort in ascending order.
Assuming you have some id or date field called "x" you would do ...
.sort()
db.foo.find().sort({x:1});
The 1 will sort ascending (oldest to newest) and -1 will sort descending (newest to oldest.)
If you use the auto created _id field it has a date embedded in...
What is the difference between char s[] and char *s?
...puts the literal string in read-only memory and copies the string to newly allocated memory on the stack. Thus making
s[0] = 'J';
legal.
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How to check whether a variable is a class or not?
...
The inspect.isclass is probably the best solution, and it's really easy to see how it's actually implemented
def isclass(object):
"""Return true if the object is a class.
Class objects provide these attributes:
__doc__ documentation string
__module__ ...
Is it better to use std::memcpy() or std::copy() in terms to performance?
...y.
I wrote a C++ SHA-2 implementation. In my test, I hash 5 strings using all four SHA-2 versions (224, 256, 384, 512), and I loop 300 times. I measure times using Boost.timer. That 300 loop counter is enough to completely stabilize my results. I ran the test 5 times each, alternating between the m...
In C, do braces act as a stack frame?
...'t have to generate code that pushes/pops anything on entry/exit (and generally, they don't).
Also note that local variables may not use any stack space at all: they could be held in CPU registers or in some other auxiliary storage location, or be optimized away entirely.
So, the d array, in theor...
Get URL query string parameters
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This is actually the best answer based on the question. The other answers only get the current URI whereas the question only specifies "from URL".
– Chris Harrison
Aug 29 '13 at 5:38
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Looping over arrays, printing both index and value
...., not splitting them on whitespace. If foo=(x 'y z'), then f "${foo[@]}" calls f with two arguments, x and 'y z'. Metadata queries like "${!foo[@]}" and "${#foo[@]}" similarly act on foo as an array.
– BallpointBen
Sep 5 '18 at 1:23
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Is it possible to import a whole directory in sass using @import?
...rails/sass-rails, features glob importing.
@import "foo/*" // import all the files in the foo folder
@import "bar/**/*" // import all the files in the bar tree
To answer the concern in another answer "If you import a directory, how can you determine import order? There's no way that doesn't...
Get the name of the currently executing method
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Even better than my first answer you can use __method__:
class Foo
def test_method
__method__
end
end
This returns a symbol – for example, :test_method. To return the method name as a string, call __method__.to_s instead.
Note: This requires Ruby 1.8.7.
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What optimizations can GHC be expected to perform reliably?
...has a lot of optimizations that it can perform, but I don't know what they all are, nor how likely they are to be performed and under what circumstances.
...