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How can I declare and use Boolean variables in a shell script?
...s before the revision on Feb 12, 2014 pertain only to the original answer, and many of the comments are wrong when associated with the revised answer. For example, Dennis Williamson's comment about bash builtin true on Jun 2, 2010 only applies to the original answer, not the revised.
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How to extract a floating number from a string [duplicate]
I have a number of strings similar to Current Level: 13.4 db. and I would like to extract just the floating point number. I say floating and not decimal as it's sometimes whole. Can RegEx do this or is there a better way?
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Rails find_or_create_by more than one attribute?
There is a handy dynamic attribute in active-record called find_or_create_by:
5 Answers
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Is Redis just a cache?
I have been reading some Redis docs and trying the tutorial at http://try.redis-db.com/ . So far, I can't see any difference between Redis and caching technologies like Velocity or the Enterprise Library Caching Framework
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What is the difference between server side cookie and client side cookie?
What is the difference between creating cookies on the server and on the client? Are these called server side cookies and client side cookies? Is there a way to create cookies that can only be read on the server or on the client?
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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
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Bottom Line
Use either COUNT(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those ...
What does CultureInfo.InvariantCulture mean?
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Not all cultures use the same format for dates and decimal / currency values.
This will matter for you when you are converting input values (read) that are stored as strings to DateTime, float, double or decimal. It will also matter if you try to format the aforementio...
Vagrant stuck connection timeout retrying
...g perfectly fine last night. I've just turned the PC on, hit vagrant up , and this is what I get:
47 Answers
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What are carriage return, linefeed, and form feed?
...when the name was coined. This is commonly escaped as \r, abbreviated CR, and has ASCII value 13 or 0x0D.
Linefeed means to advance downward to the next line; however, it has been repurposed and renamed. Used as "newline", it terminates lines (commonly confused with separating lines). This is co...
What is the difference between linear regression and logistic regression?
...ut as probabilities but it's a mistake because the output can be negative, and greater than 1 whereas probability can not. As regression might actually
produce probabilities that could be less than 0, or even bigger than
1, logistic regression was introduced.
Source: http://gerardnico.com/wiki/dat...