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In the shell, what does “ 2>&1 ” mean?
...file
Mon Jan 7 13:18:21 CET 2013
The file is overwritten each time, well now:
$ set -o noclobber
$ date > $testfile ; cat $testfile
bash: /tmp/testNoClobberDate-WW1xi9: cannot overwrite existing file
Mon Jan 7 13:18:21 CET 2013
$ date > $testfile ; cat $testfile
bash: /tmp/testNoClobberDa...
What's wrong with foreign keys?
...n get nice "on delete cascade" behavior, automatically cleaning up tables
knowing about the relationships between tables in the database helps the Optimizer plan your queries for most efficient execution, since it is able to get better estimates on join cardinality.
FKs give a pretty big hint on wh...
How to install an npm package from GitHub directly?
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Only solution I think of for now is to specify a commit with .../express.git#commit
– Gaston Sanchez
Dec 8 '14 at 18:23
40
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Android: Difference between Parcelable and Serializable?
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Now the implementation of Parcelable is as fast as Serializable, just press ALT + INSERT on any class implementing Parcelable in Android Studio and the IDE will do it.
– Ali Nem
Nov 25 '...
How can I get seconds since epoch in Javascript?
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Re: arcane magic: Per these docs, Javascript knows how to convert a Date object to a Number. This means that you can type Number(new Date()) to get a number, or even +(new Date()), or use any Date instance in a numerical context such as new Date()/1000 and Javascript wi...
How to check if an app is installed from a web-page on an iPhone?
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As far as I know you can not, from a browser, check if an app is installed or not.
But you can try redirecting the phone to the app, and if nothing happens redirect the phone to a specified page, like this:
setTimeout(function () { wind...
What is a Y-combinator? [closed]
... concept from the “functional” side of things. Most programmers don't know much at all about combinators, if they've even heard about them.
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Are there legitimate uses for JavaScript's “with” statement?
...e feature, and had never given much thought to how it might cause trouble. Now, I'm curious as to how I might make effective use of with , while avoiding its pitfalls.
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Add 2 hours to current time in MySQL?
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SELECT *
FROM courses
WHERE DATE_ADD(NOW(), INTERVAL 2 HOUR) > start_time
See Date and Time Functions for other date/time manipulation.
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What is :: (double colon) in Python when subscripting sequences?
I know that I can use something like string[3:4] to get a substring in Python, but what does the 3 mean in somesequence[::3] ?
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