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Base64 length calculation?
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Consider if you have one byte of input. That will produce four characters of output. But only two output characters are needed to encode the input. So two characters will be padding.
– David Schwartz
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Insert line after first match using sed
... about inserting a choice line of text after the first line matching a specific string using the sed command. I have ...
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Disabling swap files creation in vim
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Swap files are good if your editor crashes though (power outage etc.), just keep in mind.
– koonse
Mar 3 '15 at 2:52
2
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How to subtract 30 days from the current datetime in mysql?
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SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add
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iPhone Debugging: How to resolve 'failed to get the task for process'?
I have just added a provisioning profile to XCode (needed to support notifications and in app purchase), setup as needed the build configuration for ad hoc distribution, and tried to run the app on the device (I have done this several times in the past, without any problem).
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android asynctask sending callbacks to ui [duplicate]
...}
EDIT
Since this answer got quite popular, I want to add some things.
If you're a new to Android development, AsyncTask is a fast way to make things work without blocking UI thread. It does solves some problems indeed, there is nothing wrong with how the class works itself. However, it brings s...
How to set UICollectionViewDelegateFlowLayout?
...ller maintains a reference to a UICollectionView. The controller should modify the built-in flow layout using the UICollectionViewDelegateFlowLayout.
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Error installing libv8: ERROR: Failed to build gem native extension
... for the V8 engine used by therubyracer,
you may need to use libv8, even if you have V8 installed already. If
you wish to use your own V8 installation, rather than have it built
for you, use the --with-system-v8 option.
For more you can go through the documentation of libv8 on github
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MySQL “NOT IN” query
...ble2 ON table2.principal=table1.principal
WHERE table2.principal IS NULL
If you want to check multiple tables to make sure it's not present in any of the tables (like in SRKR's comment), you can use this:
SELECT table1.*
FROM table1
LEFT JOIN table2 ON table2.name=table1.name
LEFT JOIN table3 ON ...
Recursion or Iteration?
Is there a performance hit if we use a loop instead of recursion or vice versa in algorithms where both can serve the same purpose? Eg: Check if the given string is a palindrome.
I have seen many programmers using recursion as a means to show off when a simple iteration algorithm can fit the bill.
D...