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Variable interpolation in the shell

...h}_newstap.sh or $filepath\_newstap.sh _ is a valid character in identifiers. Dot is not, so the shell tried to interpolate $filepath_newstap. You can use set -u to make the shell exit with an error when you reference an undefined variable. ...
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Count number of records returned by group by

...rGroup, COUNT(*) OVER () AS TotalRecords from temptable group by column_1, column_2, column_3, column_4 share | improve this answer | follow | ...
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Hidden Features of Java

...d it, never heard of it before. ThreadLocals are typically not so widely known as a way to store per-thread state. Since JDK 1.5 Java has had extremely well implemented and robust concurrency tools beyond just locks, they live in java.util.concurrent and a specifically interesting example is the j...
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Generate JSON string from NSDictionary in iOS

... error:&error]; if (! jsonData) { NSLog(@"%s: error: %@", __func__, error.localizedDescription); return @"{}"; } else { return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]; } } @e...
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PSQLException: current transaction is aborted, commands ignored until end of transaction block

...tarted using Postgres... it's really annoying that Postgres does this, and now we have to be really rewrite a big bulk of our program that we are porting from Oracle to Postgres. Why isn't there an option like the first to make it behave like Oracle but without the auto-commit? ...
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What tools are there for functional programming in C?

... Sadly, this doesn’t work in practice: if you want the closure to capture anything, it requires an executable stack, which is a terrible security practice. Personally, I don’t think it is useful at all. – Demi Aug 2 '17 at...
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Remove blank attributes from an Object in Javascript

... test3 : 3, } function clean(obj) { for (var propName in obj) { if (obj[propName] === null || obj[propName] === undefined) { delete obj[propName]; } } } clean(test); If you're concerned about this property removal not running up object's proptype chain, you can also: funct...
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sqlalchemy IS NOT NULL select

... The other answer is the preferred answer now; it also avoids many IDEs including PyCharm from generating warnings. – Antti Haapala Oct 6 '16 at 7:21 ...
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How do I look inside a Python object?

... I beg to differ. dir() is just so much quicker and in 99% of the cases let's you find out what you need in combination with help(). – bayer Jun 17 '09 at 17:22 ...
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JavaScript is in array

... Try this: if(blockedTile.indexOf("118") != -1) { // element found } share | improve this answer | follo...