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Difference between single and double quotes in Bash
...o "upg")"
upg
$ echo '$(echo "upg")'
$(echo "upg")
The Bash manual has this to say:
3.1.2.2 Single Quotes
Enclosing characters in single quotes (') preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a ...
What are the underlying data structures used for Redis?
I'm trying to answer two questions in a definitive list:
3 Answers
3
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getting exception “IllegalStateException: Can not perform this action after onSaveInstanceState”
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This is the most stupid bug I have encountered so far. I had a Fragment application working perfectly for API < 11, and Force Closing on API > 11.
I really couldn't figure out what they changed inside the Activity lifecy...
Deep null checking, is there a better way?
Note: This question was asked before the introduction of the .? operator in C# 6 / Visual Studio 2015 .
16 Answers
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Cutting the videos based on start and end time using ffmpeg
...f the data starting with the previous keyframe.
With the mp4 container it is possible to cut at a non-keyframe without re-encoding using an edit list. In other words, if the closest keyframe before 3s is at 0s then it will copy the video starting at 0s and use an edit list to tell the player to st...
Strtotime() doesn't work with dd/mm/YYYY format
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Here is the simplified solution:
$date = '25/05/2010';
$date = str_replace('/', '-', $date);
echo date('Y-m-d', strtotime($date));
Result:
2010-05-25
The strtotime documentation reads:
Dates in the m/d/y or d-m-y formats...
How can I convert a datetime object to milliseconds since epoch (unix time) in Python?
...thon datetime object that I want to convert to unix time, or seconds/milliseconds since the 1970 epoch.
13 Answers
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How to Update Multiple Array Elements in mongodb
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At this moment it is not possible to use the positional operator to update all items in an array. See JIRA http://jira.mongodb.org/browse/SERVER-1243
As a work around you can:
Update each item individually
(events.0.handled eve...
What is the effect of extern “C” in C++?
...t contains just the declaration of your function. Your function definition is contained in a binary format (that was compiled by your C++ compiler) that the client C linker will then link to using the C name.
Since C++ has overloading of function names and C does not, the C++ compiler cannot just us...
What is InputStream & Output Stream? Why and when do we use them?
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The goal of InputStream and OutputStream is to abstract different ways to input and output: whether the stream is a file, a web page, or the screen shouldn't matter. All that matters is that you receive information from the stream (or send information into that str...