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The Concept of 'Hold space' and 'Pattern space' in sed
I'm confused by the two concepts in sed: hold space and pattern space. Can someone help explain them?
3 Answers
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Do threads have a distinct heap?
...far as I know each thread gets a distinct stack when the thread is created by the operating system. I wonder if each thread has a heap distinct to itself also?
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What does 'wb' mean in this code, using Python?
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File mode, write and binary. Since you are writing a .jpg file, it looks fine.
But if you supposed to read that jpg file you need to use 'rb'
More info
On Windows, 'b' appended to the mode
opens the file in binary mode, so
there are al...
Why does HTML5 form-validation allow emails without a dot?
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Because a@b is a valid email address (eg localhost is a valid domain). See http://en.wikipedia.org/wiki/Email_address#Examples
Also, keep in mind that you should always do the input validation in server. The client side vali...
Using fonts with Rails asset pipeline
I have some fonts being configured in my Scss file like so:
12 Answers
12
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For-each over an array in JavaScript
...in unless you use it with safeguards or are at least aware of why it might bite you.
Your best bets are usually
a for-of loop (ES2015+ only),
Array#forEach (spec | MDN) (or its relatives some and such) (ES5+ only),
a simple old-fashioned for loop,
or for-in with safeguards.
But there's lots mor...
To ternary or not to ternary? [closed]
...te of the ternary operator: () ? : ; I do realize that it has its place, but I have come across many programmers that are completely against ever using it, and some that use it too often.
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Convert data.frame columns from factors to characters
I have a data frame. Let's call him bob :
18 Answers
18
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How to get a variable name as a string in PHP?
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You could use get_defined_vars() to find the name of a variable that has the same value as the one you're trying to find the name of. Obviously this will not always work, since different variables often have the same values, but it's the only way I can think of to do this.
Edit: get_...
Is std::unique_ptr required to know the full definition of T?
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Adopted from here.
Most templates in the C++ standard library require that they be instantiated with complete types. However shared_ptr and unique_ptr are partial exceptions. Some, but not all of their members can be instantiated with incomplete types. The motivation for this is t...