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How do you round a floating point number in Perl?
.... For rounding to a certain number of digits, sprintf() or printf() is usually the easiest
route.
printf("%.3f", 3.1415926535); # prints 3.142
The POSIX module (part of the standard Perl distribution) implements
ceil(), floor(), and a number of other mathematical and trigonometric
func...
C library function to perform sort
...
qsort() is the function you're looking for. You call it with a pointer to your array of data, the number of elements in that array, the size of each element and a comparison function.
It does its magic and your array is sorted in-place. An example follows:
#include <st...
How to check if DST (Daylight Saving Time) is in effect, and if so, the offset?
...et returns positive numbers of minutes for zones west of UTC, which are usually stated as negative hours (since they're "behind" UTC). For example, Los Angeles is UTC–8h Standard, UTC-7h DST. getTimezoneOffset returns 480 (positive 480 minutes) in December (winter, Standard Time), rather than -480...
Difference between a Factory, Provider and a Service?
...ind of context
Provider: Provider is something microsoft "invented" (basically an abstract factory pattern) that is a way of doing a factory of factories, or having a common factory interface which allows factories to be swappable. It is used all over in the MS web stack as a way to keep components...
Getting Java version at runtime
...
Wow, that kind of blew my mind. Though in my case, all I wanted was the first two parts of the version so: Runtime.class.getPackage().getSpecificationVersion()
– Wesley Hartford
Dec 10 '14 at 21:44
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How could I use requests in asyncio?
I want to do parallel http request tasks in asyncio , but I find that python-requests would block the event loop of asyncio . I've found aiohttp but it couldn't provide the service of http request using a http proxy.
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Invert “if” statement to reduce nesting
...cked this code from the refactoring catalog. This specific refactoring is called: Replace Nested Conditional with Guard Clauses.
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Equals(=) vs. LIKE
...tify an example where these operators produce obviously different results. Allow me to quote from the MySQL manual:
Per the SQL standard, LIKE performs matching on a per-character basis, thus it can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLA...
What is the difference between require and require-dev sections in composer.json?
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Different Environments
Typically, software will run in different environments:
development
testing
staging
production
Different Dependencies in Different Environments
The dependencies which are declared in the require section of composer.json are t...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...ssing token (see below), is
replaced by the corresponding argument after all macros contained therein have been
expanded. Before being substituted, each argument’s preprocessing tokens are
completely macro replaced as if they formed the rest of the preprocessing file; no other
preprocessin...