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Perform an action in every sub-directory using Bash
... command, this is more concise:
for D in *; do [ -d "${D}" ] && my_command; done
Or an even more concise version (thanks @enzotib). Note that in this version each value of D will have a trailing slash:
for D in */; do my_command; done
...
How to avoid overflow in expr. A * B - C * D
...e their types are: signed long long int A, B, C, D;
Each number can be really big (not overflowing its type). While A*B could cause overflow, at same time expression A*B - C*D can be really small. How can I compute it correctly?
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Converting a list to a set changes element order
...ct.fromkeys(x for x in a if x not in b)
{2: None, 210: None}
b doesn't really need to be ordered here – you could use a set as well. Note that a.keys() - b.keys() returns the set difference as a set, so it won't preserve the insertion order.
In older versions of Python, you can use collections....
React.js: onChange event for contentEditable
...hich fixes a bug in my implementation.
Use the onInput event, and optionally onBlur as a fallback. You might want to save the previous contents to prevent sending extra events.
I'd personally have this as my render function.
var handleChange = function(event){
this.setState({html: event.ta...
How to test if list element exists?
...
This is actually a bit trickier than you'd think. Since a list can actually (with some effort) contain NULL elements, it might not be enough to check is.null(foo$a). A more stringent test might be to check that the name is actually defin...
How to post pictures to instagram using API
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@usama unfortunately not officially but I've heard rumours that if you go on to their website and scale it down to mobile view you can. Not tried it myself though
– Albzi
Jul 2 '17 at 13:16
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Regex exactly n OR m times
...character before) as you can see here: https://regex101.com/r/oC5oJ4/1
Finally, to match the one character distant match, you can add a positive look ahead (?=) on the "no 'x' after" or a positive look behind (?<=) on the "no 'x' before", like this: https://regex101.com/r/mC4uX3/1
(?<=[^x]|^...
Java ByteBuffer to String
... Charset charset). You can use the same offset and length values for both calls.
– Andy Thomas
Jul 24 '15 at 14:55
1
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How do you find the current user in a Windows environment?
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The extra information with all the environment variables makes this a wonderful extended answer.
– bballdave025
May 21 at 19:32
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`static` keyword inside function?
...e value of the given variable ($has_run in your example) between multiple calls.
You could use this for different purposes, for example:
function doStuff() {
static $cache = null;
if ($cache === null) {
$cache = '%heavy database stuff or something%';
}
// code using $cache
}
In th...