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How does the socket API accept() function work?
The socket API is the de-facto standard for TCP/IP and UDP/IP communications (that is, networking code as we know it). However, one of its core functions, accept() is a bit magical.
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Why are floating point numbers inaccurate?
...t numbers are represented a lot like scientific notation: with an exponent and a mantissa (also called the significand). A very simple number, say 9.2, is actually this fraction:
5179139571476070 * 2 -49
Where the exponent is -49 and the mantissa is 5179139571476070. The reason it is impossibl...
How to validate an email address in PHP
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The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function:
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
// invalid emailaddress
}
Additionally you can check whether the do...
Why do indexes in XPath start with 1 and not 0?
Some colleagues and I were comparing past languages we had programmed in and were talking about our experience with VBScript with its odd features such as 1-based index instead of 0-based indexes like almost every other language has, the reasoning being that it was a language for users (e.g....
How to store standard error in a variable
... the error file thus:
ERROR=$(</tmp/Error)
The shell recognizes this and doesn't have to run 'cat' to get the data.
The bigger question is hard. I don't think there's an easy way to do it. You'd have to build the entire pipeline into the sub-shell, eventually sending its final standard outp...
Symbolic links and synced folders in Vagrant
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I suspect the OP and many people viewing this question were using the term "shared" and "synced" interchangeably. Note the OP's second bullet point which strongly implies he was using shared folders, but tried switching to an rsynced folder b...
Can you change what a symlink points to after it is created?
Does any operating system provide a mechanism (system call — not command line program) to change the pathname referenced by a symbolic link (symlink) — other than by unlinking the old one and creating a new one?
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The “unexpected ++” error in jslint [duplicate]
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@MattClarkson: According to Crockford: The increment ++ and decrement -- operators make it possible to write in an extremely terse style. In languages such as C, they made it possible to write one-liners that: for (p = src, q = dest; !*p; p++, q++) *q = *p; Most of the buffer over...
unix - head AND tail of file
Say you have a txt file, what is the command to view the top 10 lines and bottom 10 lines of file simultaneously?
20 Answer...
An example of how to use getopts in bash
...t;0 (for the sake of simplicity I didn't differentiate between those cases and nobody forces you to print the usage text in the latter case). I have seen programs which always return != 0, though, even on -h/--help. Maybe I should update the snippet in case people use this as boilerplate (I hope not...