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How to output only captured groups with sed?
...as well as specifying what you do want.
string='This is a sample 123 text and some 987 numbers'
echo "$string" | sed -rn 's/[^[:digit:]]*([[:digit:]]+)[^[:digit:]]+([[:digit:]]+)[^[:digit:]]*/\1 \2/p'
This says:
don't default to printing each line (-n)
exclude zero or more non-digits
include on...
Why `null >= 0 && null
...utine that increments the value of a variable by 1 if its type is number and assigns 0 to the variable if not, where the variable is initially null or undefined .
...
How to update gradle in android studio?
I installed Android Studio 0.1.9. Today I got and update to version 0.2 and of course I updated. After the installation I restarted Android Studio but now I get this message:
...
Is object empty? [duplicate]
...y = Object.prototype.hasOwnProperty;
function isEmpty(obj) {
// null and undefined are "empty"
if (obj == null) return true;
// Assume if it has a length property with a non-zero value
// that that property is correct.
if (obj.length > 0) return false;
if (obj.length...
Check if at least two out of three booleans are true
...ewer recently asked me this question: given three boolean variables, a, b, and c, return true if at least two out of the three are true.
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Black transparent overlay on image hover with only CSS?
...t;/div>
As for the CSS, set optional dimensions on the .image element, and relatively position it. If you are aiming for a responsive image, just omit the dimensions and this will still work (example). It's just worth noting that the dimensions must be on the parent element as opposed to the img...
Stack vs heap allocation of structs in Go, and how they relate to garbage collection
I'm new to Go and I'm experiencing a bit of congitive dissonance between C-style stack-based programming where automatic variables live on the stack and allocated memory lives on the heap and and Python-style stack-based-programming where the only thing that lives on the stack are references/pointer...
Performance of foreach, array_map with lambda and array_map with static function
...2 compare with mcfedr's answer below for additional results without XDebug and a more recent PHP version.
function lap($func) {
$t0 = microtime(1);
$numbers = range(0, 1000000);
$ret = $func($numbers);
$t1 = microtime(1);
return array($t1 - $t0, $ret);
}
function useForeach($numbers) {...
Is floating point math broken?
...is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose denominator is not a power of two cannot be exactly re...
How to create GUID / UUID?
...vaScript. I'm not sure what routines are available on all browsers, how "random" and seeded the built-in random number generator is, etc.
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